Tracking Human Ancestry | Biology

<!DOCTYPE html> <html lang="en" dir="ltr"> <head>  <meta http-equiv="X-UA-Compatible" content="ie=edge"> <meta charset="utf-8"> <base href="https://www.visionlearning.com"> <title>Tracking Human Ancestry | Biology | Visionlearning</title> <link rel="canonical" href="https://www.visionlearning.com/en/library/biology/2/tracking-human-ancestry/248"> <meta name="description" content="Using genetic markers passed down through the male or female line, scientists can construct family trees going back thousands of years. This module introduces haplotypes – genetic sequences that we inherit from only one parent. As an example, the module looks at the degree of interbreeding between now-extinct Neanderthals and modern humans as determined through an analysis of Y-chromosome haplotypes (male lineage) and mitochondrial DNA haplotypes (female lineage)."> <meta name="keywords" content="y-chromosome, mitochondrial, DNA, haplotype, human genetics"> <meta name="viewport" content="width=device-width, initial-scale=1.0, shrink-to-fit=no"> <meta name="msvalidate.01" content="D8E20F39AD48052260032E56DE409970"> <script type="application/ld+json"> { "@context": "http://schema.org/", "@type": "Article", "mainEntityOfPage": { "@type": "WebPage", "@id": "https://visionlearning.com/en/library/biology/2/tracking-human-ancestry/248" }, "name": "Tracking Human Ancestry", "headline": "Tracking Human Ancestry: The Y-chromosome and mitochondrial DNA", "author": [ { "@type": "Person", "name": "David Warmflash, MD" } , { "@type": "Person", "name": "Nathan H Lents, Ph.D." }], "datePublished": "2017-04-01 18:29:08", "dateModified": "2017-02-12T08:30:00+05:00", "image": { "@type": "ImageObject", "url": "/img/library/moduleImages/featured_image_248-23061209063715.jpg", "width": 696, "height": 464 }, "publisher": { "@type": "Organization", "name": "Visionlearning, Inc.", "logo": { "@type": "ImageObject", "url": "http://visionlearning.com/images/logo.png", "width": 278, "height": 60 } }, "description": "Using genetic markers passed down through the male or female line, scientists can construct family trees going back thousands of years. This module introduces haplotypes – genetic sequences that we inherit from only one parent. As an example, the module looks at the degree of interbreeding between now-extinct Neanderthals and modern humans as determined through an analysis of Y-chromosome haplotypes (male lineage) and mitochondrial DNA haplotypes (female lineage).", "keywords": "y-chromosome, mitochondrial, DNA, haplotype, human genetics", "inLanguage": { "@type": "Language", "name": "English", "alternateName": "en" }, "copyrightHolder": { "@type": "Organization", "name": "Visionlearning, Inc." }, "copyrightYear": "2017"} </script> <meta property="og:url" content="https://visionlearning.com/en/library/biology/2/tracking-human-ancestry/248"> <meta property="og:title" content="Tracking Human Ancestry | Biology | Visionlearning" /> <meta property="og:type" content="website"> <meta property="og:site_name" content="Visionlearning"> <meta property="og:description" content="Using genetic markers passed down through the male or female line, scientists can construct family trees going back thousands of years. This module introduces haplotypes – genetic sequences that we inherit from only one parent. As an example, the module looks at the degree of interbreeding between now-extinct Neanderthals and modern humans as determined through an analysis of Y-chromosome haplotypes (male lineage) and mitochondrial DNA haplotypes (female lineage)."> <meta property="og:image" content="https://visionlearning.com/images/logo.png"> <meta property="fb:admins" content="100000299664514"> <link rel="stylesheet" type="text/css" href="/css/visionlearning.css">  <link rel="stylesheet" type="text/css" href="/css/visionlearning-icons.css">  <link rel="preload" href="https://fonts.gstatic.com"> <link rel="preload" href="https://fonts.googleapis.com/css2?family=Open+Sans:ital,wght@0,400;0,700;1,400;1,700&family=Schoolbell&display=swap"> <style> textarea.myEditor { width: 90%; height: 350px; } </style> <script type="text/x-mathjax-config" src="/js/mathjax-config.js"></script> <script id="MathJax-script" async src="/js/mathjax/tex-svg.js"></script> <script async 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href="/en/library/environmental-science/61/biodiversity-i/276">Biodiversity I</a></li> <li><a href="/en/library/environmental-science/61/biodiversity-ii/281">Biodiversity II</a></li> <li><a href="/en/library/environmental-science/61/ecosystem-services/279">Ecosystem Services</a></li> <li><a href="/en/library/environmental-science/61/population-biology/287">Population Biology</a></li> </ul> </div> <button class="accordion__button" id="acc-button-earth-cycles" data-accordion="button" aria-controls="acc-panel-earth-cycles" aria-expanded="false"> <span class="accordion__button__label"> Earth Cycles </span> </button> <div class="accordion__panel" id="acc-panel-earth-cycles" data-accordion="panel" aria-labelledby="acc-button-earth-cycles" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/the-nitrogen-cycle/98">The Nitrogen Cycle</a></li> <li><a href="/en/library/environmental-science/61/the-carbon-cycle/95">The Carbon Cycle</a></li> <li><a href="/en/library/environmental-science/61/the-phosphorus-cycle/197">The Phosphorus Cycle</a></li> </ul> </div> <button class="accordion__button" id="acc-button-scientific-research" data-accordion="button" aria-controls="acc-panel-scientific-research" aria-expanded="false"> <span class="accordion__button__label"> Scientific Research </span> </button> <div class="accordion__panel" id="acc-panel-scientific-research" data-accordion="panel" aria-labelledby="acc-button-scientific-research" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/environmental-science/61/collaborative-research-in-the-arctic-towards-understanding-climate-change/183">Collaborative Research in the Arctic Towards Understanding Climate Change</a></li> <li><a href="/en/library/environmental-science/61/atmospheric-chemistry-research-that-changed-global-policy/211">Atmospheric Chemistry Research that Changed Global Policy</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-general-science" data-accordion="button" aria-controls="acc-panel-general-science" aria-expanded="false"> <span class="accordion__button__label"> General Science </span> </button> <div class="accordion__panel" id="acc-panel-general-science" data-accordion="panel" aria-labelledby="acc-button-general-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-methods" data-accordion="button" aria-controls="acc-panel-methods" aria-expanded="false"> <span class="accordion__button__label"> Methods </span> </button> <div class="accordion__panel" id="acc-panel-methods" data-accordion="panel" aria-labelledby="acc-button-methods" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/the-scientific-method/45">The Scientific Method</a></li> </ul> </div> <button class="accordion__button" id="acc-button-measurement" data-accordion="button" aria-controls="acc-panel-measurement" aria-expanded="false"> <span class="accordion__button__label"> Measurement </span> </button> <div class="accordion__panel" id="acc-panel-measurement" data-accordion="panel" aria-labelledby="acc-button-measurement" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/the-metric-system/47">The Metric System</a></li> </ul> </div> <button class="accordion__button" id="acc-button-physical-properties" data-accordion="button" aria-controls="acc-panel-physical-properties" aria-expanded="false"> <span class="accordion__button__label"> Physical Properties </span> </button> <div class="accordion__panel" id="acc-panel-physical-properties" data-accordion="panel" aria-labelledby="acc-button-physical-properties" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/general-science/3/temperature/48">Temperature</a></li> <li><a href="/en/library/general-science/3/density-and-buoyancy/37">Density and Buoyancy</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-math-in-science" data-accordion="button" aria-controls="acc-panel-math-in-science" aria-expanded="false"> <span class="accordion__button__label"> Math in Science </span> </button> <div class="accordion__panel" id="acc-panel-math-in-science" data-accordion="panel" aria-labelledby="acc-button-math-in-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-equations" data-accordion="button" aria-controls="acc-panel-equations" aria-expanded="false"> <span class="accordion__button__label"> Equations </span> </button> <div class="accordion__panel" id="acc-panel-equations" data-accordion="panel" aria-labelledby="acc-button-equations" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/unit-conversion/144">Unit Conversion</a></li> <li><a href="/en/library/math-in-science/62/linear-equations/194">Linear Equations</a></li> <li><a href="/en/library/math-in-science/62/exponential-equations-i/206">Exponential Equations I</a></li> <li><a href="/en/library/math-in-science/62/exponential-equations-ii/210">Exponential Equations II</a></li> <li><a href="/en/library/math-in-science/62/scientific-notation/250">Scientific Notation</a></li> <li><a href="/en/library/math-in-science/62/measurement/257">Measurement</a></li> </ul> </div> <button class="accordion__button" id="acc-button-statistics" data-accordion="button" aria-controls="acc-panel-statistics" aria-expanded="false"> <span class="accordion__button__label"> Statistics </span> </button> <div class="accordion__panel" id="acc-panel-statistics" data-accordion="panel" aria-labelledby="acc-button-statistics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/introduction-to-descriptive-statistics/218">Introduction to Descriptive Statistics</a></li> <li><a href="/en/library/math-in-science/62/introduction-to-inferential-statistics/224">Introduction to Inferential Statistics</a></li> <li><a href="/en/library/math-in-science/62/statistical-techniques/239">Statistical Techniques</a></li> </ul> </div> <button class="accordion__button" id="acc-button-trigonometric-functions" data-accordion="button" aria-controls="acc-panel-trigonometric-functions" aria-expanded="false"> <span class="accordion__button__label"> Trigonometric Functions </span> </button> <div class="accordion__panel" id="acc-panel-trigonometric-functions" data-accordion="panel" aria-labelledby="acc-button-trigonometric-functions" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/math-in-science/62/wave-mathematics/131">Wave Mathematics</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-physics" data-accordion="button" aria-controls="acc-panel-physics" aria-expanded="false"> <span class="accordion__button__label"> Physics </span> </button> <div class="accordion__panel" id="acc-panel-physics" data-accordion="panel" aria-labelledby="acc-button-physics" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-light-and-optics" data-accordion="button" aria-controls="acc-panel-light-and-optics" aria-expanded="false"> <span class="accordion__button__label"> Light and Optics </span> </button> <div class="accordion__panel" id="acc-panel-light-and-optics" data-accordion="panel" aria-labelledby="acc-button-light-and-optics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/physics/24/the-nature-of-light/132">The Nature of Light</a></li> <li><a href="/en/library/physics/24/electromagnetism-and-light/138">Electromagnetism and Light</a></li> </ul> </div> <button class="accordion__button" id="acc-button-mechanics" data-accordion="button" aria-controls="acc-panel-mechanics" aria-expanded="false"> <span class="accordion__button__label"> Mechanics </span> </button> <div class="accordion__panel" id="acc-panel-mechanics" data-accordion="panel" aria-labelledby="acc-button-mechanics" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/physics/24/defining-energy/199">Defining Energy</a></li> <li><a href="/en/library/physics/24/waves-and-wave-motion/102">Waves and Wave Motion</a></li> <li><a href="/en/library/physics/24/gravity/118">Gravity</a></li> <li><a href="/en/library/physics/24/thermodynamics-i/200">Thermodynamics I</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-process-of-science" data-accordion="button" aria-controls="acc-panel-process-of-science" aria-expanded="false"> <span class="accordion__button__label"> Process of Science </span> </button> <div class="accordion__panel" id="acc-panel-process-of-science" data-accordion="panel" aria-labelledby="acc-button-process-of-science" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-introduction" data-accordion="button" aria-controls="acc-panel-introduction" aria-expanded="false"> <span class="accordion__button__label"> Introduction </span> </button> <div class="accordion__panel" id="acc-panel-introduction" data-accordion="panel" aria-labelledby="acc-button-introduction" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-process-of-science/176">The Process of Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-the-culture-of-science" data-accordion="button" aria-controls="acc-panel-the-culture-of-science" aria-expanded="false"> <span class="accordion__button__label"> The Culture of Science </span> </button> <div class="accordion__panel" id="acc-panel-the-culture-of-science" data-accordion="panel" aria-labelledby="acc-button-the-culture-of-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-nature-of-scientific-knowledge/185">The Nature of Scientific Knowledge</a></li> <li><a href="/en/library/process-of-science/49/scientists-and-the-scientific-community/172">Scientists and the Scientific Community</a></li> <li><a href="/en/library/process-of-science/49/scientific-ethics/161">Scientific Ethics</a></li> <li><a href="/en/library/process-of-science/49/scientific-institutions-and-societies/162">Scientific Institutions and Societies</a></li> </ul> </div> <button class="accordion__button" id="acc-button-ideas-in-science" data-accordion="button" aria-controls="acc-panel-ideas-in-science" aria-expanded="false"> <span class="accordion__button__label"> Ideas in Science </span> </button> <div class="accordion__panel" id="acc-panel-ideas-in-science" data-accordion="panel" aria-labelledby="acc-button-ideas-in-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/theories-hypotheses-and-laws/177">Theories, Hypotheses, and Laws</a></li> <li><a href="/en/library/process-of-science/49/scientific-controversy/181">Scientific Controversy</a></li> <li><a href="/en/library/process-of-science/49/creativity-in-science/182">Creativity in Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-research-methods" data-accordion="button" aria-controls="acc-panel-research-methods" aria-expanded="false"> <span class="accordion__button__label"> Research Methods </span> </button> <div class="accordion__panel" id="acc-panel-research-methods" data-accordion="panel" aria-labelledby="acc-button-research-methods" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/the-practice-of-science/148">The Practice of Science</a></li> <li><a href="/en/library/process-of-science/49/experimentation-in-scientific-research/150">Experimentation in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/description-in-scientific-research/151">Description in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/comparison-in-scientific-research/152">Comparison in Scientific Research</a></li> <li><a href="/en/library/process-of-science/49/modeling-in-scientific-research/153">Modeling in Scientific Research</a></li> </ul> </div> <button class="accordion__button" id="acc-button-data" data-accordion="button" aria-controls="acc-panel-data" aria-expanded="false"> <span class="accordion__button__label"> Data </span> </button> <div class="accordion__panel" id="acc-panel-data" data-accordion="panel" aria-labelledby="acc-button-data" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/data-analysis-and-interpretation/154">Data Analysis and Interpretation</a></li> <li><a href="/en/library/process-of-science/49/uncertainty-error-and-confidence/157">Uncertainty, Error, and Confidence</a></li> <li><a href="/en/library/process-of-science/49/statistics-in-science/155">Statistics in Science</a></li> <li><a href="/en/library/process-of-science/49/using-graphs-and-visual-data-in-science/156">Using Graphs and Visual Data in Science</a></li> </ul> </div> <button class="accordion__button" id="acc-button-scientific-communication" data-accordion="button" aria-controls="acc-panel-scientific-communication" aria-expanded="false"> <span class="accordion__button__label"> Scientific Communication </span> </button> <div class="accordion__panel" id="acc-panel-scientific-communication" data-accordion="panel" aria-labelledby="acc-button-scientific-communication" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/process-of-science/49/understanding-scientific-journals-and-articles/158">Understanding Scientific Journals and Articles</a></li> <li><a href="/en/library/process-of-science/49/utilizing-the-scientific-literature/173">Utilizing the Scientific Literature</a></li> <li><a href="/en/library/process-of-science/49/peer-review-in-scientific-publishing/159">Peer Review in Scientific Publishing</a></li> <li><a href="/en/library/process-of-science/49/the-how-and-why-of-scientific-meetings/186">The How and Why of Scientific Meetings</a></li> </ul> </div> </div> </div> <button class="accordion__button" id="acc-button-scientists-and-research" data-accordion="button" aria-controls="acc-panel-scientists-and-research" aria-expanded="false"> <span class="accordion__button__label"> Scientists and Research </span> </button> <div class="accordion__panel" id="acc-panel-scientists-and-research" data-accordion="panel" aria-labelledby="acc-button-scientists-and-research" role="region"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-button-scientific-research" data-accordion="button" aria-controls="acc-panel-scientific-research" aria-expanded="false"> <span class="accordion__button__label"> Scientific Research </span> </button> <div class="accordion__panel" id="acc-panel-scientific-research" data-accordion="panel" aria-labelledby="acc-button-scientific-research" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/scientists-and-research/58/collaborative-research-in-the-arctic-towards-understanding-climate-change/183">Collaborative Research in the Arctic Towards Understanding Climate Change</a></li> <li><a href="/en/library/scientists-and-research/58/from-stable-chromosomes-to-jumping-genes/184">From Stable Chromosomes to Jumping Genes</a></li> <li><a href="/en/library/scientists-and-research/58/an-elegant-experiment-to-test-the-process-of-dna-replication/187">An Elegant Experiment to Test the Process of DNA Replication</a></li> <li><a href="/en/library/scientists-and-research/58/the-founding-of-neuroscience/233">The Founding of Neuroscience</a></li> <li><a href="/en/library/scientists-and-research/58/tracking-endangered-jaguars-across-the-border/189">Tracking Endangered Jaguars across the Border</a></li> <li><a href="/en/library/scientists-and-research/58/atmospheric-chemistry-research-that-changed-global-policy/211">Atmospheric Chemistry Research that Changed Global Policy</a></li> <li><a href="/en/library/scientists-and-research/58/revolutionizing-medicine-with-monoclonal-antibodies/220">Revolutionizing Medicine with Monoclonal Antibodies</a></li> <li><a href="/en/library/scientists-and-research/58/uncovering-the-mysteries-of-chronic-mountain-sickness/238">Uncovering the Mysteries of Chronic Mountain Sickness</a></li> </ul> </div> <button class="accordion__button" id="acc-button-profiles-in-science" data-accordion="button" aria-controls="acc-panel-profiles-in-science" aria-expanded="false"> <span class="accordion__button__label"> Profiles in Science </span> </button> <div class="accordion__panel" id="acc-panel-profiles-in-science" data-accordion="panel" aria-labelledby="acc-button-profiles-in-science" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/scientists-and-research/58/luis-e.-miramontes/232">Luis E. Miramontes</a></li> <li><a href="/en/library/scientists-and-research/58/bernardo-houssay/237">Bernardo Houssay</a></li> <li><a href="/en/library/scientists-and-research/58/craig-lee/256">Craig Lee</a></li> <li><a href="/en/library/scientists-and-research/58/david-ho/241">David Ho</a></li> <li><a href="/en/library/scientists-and-research/58/louis-tompkins-wright/244">Louis Tompkins Wright</a></li> <li><a href="/en/library/scientists-and-research/58/carlos-j.-finlay/217">Carlos J. Finlay</a></li> <li><a href="/en/library/scientists-and-research/58/cecilia-payne/290">Cecilia Payne</a></li> <li><a href="/en/library/scientists-and-research/58/jazmin-scarlett/291">Jazmin Scarlett</a></li> <li><a href="/en/library/scientists-and-research/58/ramari-stewart/292">Ramari Stewart</a></li> <li><a href="/en/library/scientists-and-research/58/johnson-cerda/300">Johnson Cerda</a></li> <li><a href="/en/library/scientists-and-research/58/ellen-ochoa/201">Ellen Ochoa</a></li> <li><a href="/en/library/scientists-and-research/58/ruth-benerito/205">Ruth Benerito</a></li> <li><a href="/en/library/scientists-and-research/58/franklin-chang-díaz/219">Franklin Chang Díaz</a></li> <li><a href="/en/library/scientists-and-research/58/percy-lavon-julian/221">Percy Lavon Julian</a></li> <li><a href="/en/library/scientists-and-research/58/luis-walter-alvarez/229">Luis Walter Alvarez</a></li> <li><a href="/en/library/scientists-and-research/58/france-anne-dominic-córdova/230">France Anne-Dominic Córdova</a></li> </ul> </div> </div> </div> </div> </div> </li> <li>  <button class="button" data-toggle="dropdown">Biology </button> <div class="nav__dropdown box-shadow-1 padding-1"> <div class="accordion accordion--secondary font-size-sm"> <div class="accordion accordion--secondary"> <button class="accordion__button" id="acc-sub-button-biological-molecules" data-accordion="button" aria-controls="acc-sub-panel-biological-molecules" aria-expanded="false"> <span class="accordion__button__label"> Biological Molecules </span> </button> <div class="accordion__panel" id="acc-sub-panel-biological-molecules" data-accordion="panel" aria-labelledby="acc-sub-button-biological-molecules" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/biology/2/carbohydrates/61">Carbohydrates</a></li> <li><a href="/en/library/biology/2/fats-and-proteins/62">Fats and Proteins</a></li> <li><a href="/en/library/biology/2/biological-proteins/243">Biological Proteins</a></li> <li><a href="/en/library/biology/2/blood-biology-i/242">Blood Biology I</a></li> <li><a href="/en/library/biology/2/lipids/207">Lipids</a></li> </ul> </div> <button class="accordion__button" id="acc-sub-button-cell-biology" data-accordion="button" aria-controls="acc-sub-panel-cell-biology" aria-expanded="false"> <span class="accordion__button__label"> Cell Biology </span> </button> <div class="accordion__panel" id="acc-sub-panel-cell-biology" data-accordion="panel" aria-labelledby="acc-sub-button-cell-biology" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/biology/2/discovery-and-structure-of-cells/64">Discovery and Structure of Cells</a></li> <li><a href="/en/library/biology/2/respiration/285">Respiration</a></li> <li><a href="/en/library/biology/2/membranes-i/198">Membranes I</a></li> <li><a href="/en/library/biology/2/membranes-ii/204">Membranes II</a></li> <li><a href="/en/library/biology/2/cellular-organelles-i/195">Cellular Organelles I</a></li> <li><a href="/en/library/biology/2/cell-division-i/196">Cell Division I</a></li> <li><a href="/en/library/biology/2/cell-division-ii/212">Cell Division II</a></li> <li><a href="/en/library/biology/2/membranes-and-chemical-transport/106">Membranes and Chemical Transport</a></li> </ul> </div> <button class="accordion__button" id="acc-sub-button-energy-in-living-systems" data-accordion="button" aria-controls="acc-sub-panel-energy-in-living-systems" aria-expanded="false"> <span class="accordion__button__label"> Energy in Living Systems </span> </button> <div class="accordion__panel" id="acc-sub-panel-energy-in-living-systems" data-accordion="panel" aria-labelledby="acc-sub-button-energy-in-living-systems" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/biology/2/energy-metabolism-i/215">Energy Metabolism I</a></li> <li><a href="/en/library/biology/2/energy-metabolism-ii/225">Energy Metabolism II</a></li> <li><a href="/en/library/biology/2/photosynthesis-i/192">Photosynthesis I</a></li> </ul> </div> <button class="accordion__button" id="acc-sub-button-evolutionary-biology" data-accordion="button" aria-controls="acc-sub-panel-evolutionary-biology" aria-expanded="false"> <span class="accordion__button__label"> Evolutionary Biology </span> </button> <div class="accordion__panel" id="acc-sub-panel-evolutionary-biology" data-accordion="panel" aria-labelledby="acc-sub-button-evolutionary-biology" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/biology/2/origins-of-life-i/226">Origins of Life I</a></li> <li><a href="/en/library/biology/2/origins-of-life-ii/227">Origins of Life II</a></li> <li><a href="/en/library/biology/2/extinction/295">Extinction</a></li> <li><a href="/en/library/biology/2/mass-extinctions/294">Mass Extinctions</a></li> <li><a href="/en/library/biology/2/charles-darwin-i/110">Charles Darwin I</a></li> <li><a href="/en/library/biology/2/charles-darwin-ii/111">Charles Darwin II</a></li> <li><a href="/en/library/biology/2/charles-darwin-iii/112">Charles Darwin III</a></li> <li><a href="/en/library/biology/2/adaptation/68">Adaptation</a></li> <li><a href="/en/library/biology/2/taxonomy-i/70">Taxonomy I</a></li> <li><a href="/en/library/biology/2/taxonomy-ii/89">Taxonomy II</a></li> <li><a href="/en/library/biology/2/introduction-to-paleoanthropology/258">Introduction to Paleoanthropology</a></li> <li><a href="/en/library/biology/2/the-piltdown-hoax/263">The Piltdown Hoax</a></li> <li><a href="/en/library/biology/2/future-of-human-evolution/259">Future of Human Evolution</a></li> </ul> </div> <button class="accordion__button" id="acc-sub-button-genetics" data-accordion="button" aria-controls="acc-sub-panel-genetics" aria-expanded="false"> <span class="accordion__button__label"> Genetics </span> </button> <div class="accordion__panel" id="acc-sub-panel-genetics" data-accordion="panel" 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aria-labelledby="acc-sub-button-ecology" role="region"> <ul class="nav text-color-link"> <li><a href="/en/library/biology/2/biodiversity-i/276">Biodiversity I</a></li> <li><a href="/en/library/biology/2/ecosystem-services/279">Ecosystem Services</a></li> <li><a href="/en/library/biology/2/animal-ecology/283">Animal Ecology</a></li> <li><a href="/en/library/biology/2/biodiversity-ii/281">Biodiversity II</a></li> <li><a href="/en/library/biology/2/animal-behavior/286">Animal Behavior</a></li> <li><a href="/en/library/biology/2/population-biology/287">Population Biology</a></li> <li><a href="/en/library/biology/2/trophic-ecology/293">Trophic Ecology</a></li> </ul> </div> </div> </div> </div> </li> </ul> </nav>  <div id="theTop"></div> <main id="skip-header-content"> <div class="margin-bottom-5"> <article class="container wide module"> <header class="grid grid--sidebar-right module__header"> <div class="module__header__title"> <span class="subcategory"> <strong><em>Genetics</em></strong> </span> <h1>Tracking Human Ancestry: <sub><em>The Y-chromosome and mitochondrial DNA</em></sub></h1> <p class="byline">by David Warmflash, MD, Nathan H Lents, Ph.D.</p> <nav class="module__header__tabs"> <ul class="tabs-nav tabs-nav--horizontal library"> <li> <a href="/en/library/biology/2/tracking-human-ancestry/248/reading" aria-current="page" >Reading</a> </li> <li> <a href="/en/library/biology/2/tracking-human-ancestry/248/quiz">Quiz</a> </li> <li> <a href="/en/library/biology/2/tracking-human-ancestry/248/resources">Teach with this</a> </li> </ul> </nav> </div> </header> <hr class="divider"/>   <div class="grid grid--sidebar-right grid--divider"> <div class="order-2 order-1--lg module__main"> <div class="narrow margin-x-auto margin-y-5"> <div class="accordion margin-bottom-5">  <button class="accordion__button" id="acc-button-key-concepts" data-accordion="button" aria-controls="acc-panel-key-concepts" aria-expanded="true" tabindex="0"> Did you know? </button> <div class="accordion__panel shown show" id="acc-panel-key-concepts" data-accordion="panel" aria-labelledby="acc-button-key-concepts" role="region"> <div class="accordion__panel__content"> <p>Did you know that DNA testing of 50,000-year-old bones showed that the original Neanderthal man did not descend from the same mother as modern humans? However, male lineage tests revealed that 8% of the non-African human gene pool consists of Neanderthal DNA. Certain genetic sequences called haplotypes are passed on only by males or by females, so to get a complete picture of the ancestry of a population, scientists generate one family tree based on the male line and another based on the female line.</p> </div> </div>  <button class="accordion__button" id="acc-button-table-of-contents" data-accordion="button" aria-controls="acc-panel-table-of-contents" aria-expanded="false" tabindex="0"> Key concepts </button> <div class="accordion__panel" id="acc-panel-table-of-contents" data-accordion="panel" aria-labelledby="acc-button-table-of-contents" role="region" aria-hidden="true"> <div class="accordion__panel__content"> <ul class="bulleted"><li><p>Haplotypes are genetic sequences that we inherit from only one parent. There are two types: Y-chromosomes, inherited from your father, and mitochondrial DNA, inherited from your mother.</p></li> <li><p>Y-chromosome haplotypes are subject to random mutation and the discovery of numerous different haplotypes led scientists to construct the Y-chromosome family tree.</p></li> <li><p>Mitochondria are organelles in all eukaryotic cells and have some of their own DNA. All of your mitochondria come from your mother and help to build a mtDNA family tree.</p></li> <li><p>The most recent common ancestor (MRCA) is someone who exists in everyone's family tree.</p></li> <li><p>When scientists study populations of a given ethnic group, they generate one family tree based on the populations' Y-chromosomes and another one based on mtDNA.</p></li> <li><p>When constructing family trees, often an ancestor will appear in multiple places - this is a phenomenon known as pedigree collapse.</p></li></ul> </div> </div>  <button class="accordion__button" id="acc-button-terms-you-should-know" data-accordion="button" aria-controls="acc-panel-terms-you-should-know" aria-expanded="false" tabindex="0"> Terms you should know </button> <div class="accordion__panel" id="acc-panel-terms-you-should-know" data-accordion="panel" aria-labelledby="acc-button-terms-you-should-know" role="region" aria-hidden="true"> <div class="accordion__panel__content"> <dl> <dt>genetic sequence </dt> <dd> also called DNA sequence; the precise order of the four nucleotide bases in a DNA molecule, resulting in an individual’s genetic traits. </dd> <dt>Mendelian </dt> <dd> relating to the ideas proposed by Gregor Mendel, considered the founding father of genetics, whose painstaking experiments with pea plants resulted in a description of how dominant and recessive genes are passed from one generation to the next. </dd> <dt><a href="/en/glossary/view/neanderthal">Neanderthal </a></dt> <dd> an extinct species of humans who lived from approximately 300,000 to 30,000 years ago.</dd> </dl> </div> </div> </div> <hr class="border-color-dark" /> <section> <div class="container narrow"> <p>How much is your <mark class="term" data-term="genome" data-term-def="All of the genetic material of an organism, carried in its DNA." data-term-url="/en/glossary/view/genome/8517">genome</mark> (Figure 1) influenced by a great-great-great-great grandparent? The question is tricky since you have 64 of them. In theory, the number of ancestors you have double each <mark class="term" data-term="generation" data-term-def="Offspring at the same step in the line of descent from a common ancestor." data-term-url="/en/glossary/view/generation/8293">generation</mark> backward. When you reach 25 or 30 generations into the past, 600-700 years ago, the number of ancestors you should theoretically expect is larger than the entire human <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">population</mark> of that time. That is obviously impossible and begins to show how challenging it can be to track ancestry. There’s something wrong with our math.</p> <div class="figure"> <figure> <button class="lightbox-button lightbox-button--icon" data-lightbox="" data-lightbox-src="/img/library/large_images/image_11352.jpg"> <img src="/img/library/modules/mid248/Image/VLObject-11352-170311040343.jpg" alt="Figure 1: The genome is the entire set of genetic instructions found in a cell. In humans, the genome consists of 23 pairs of chromosomes (found in the nucleus), plus a small chromosome (found in the cells' mitochondria)." /> </button> <figcaption> <p><strong>Figure 1</strong>: The genome is the entire set of genetic instructions found in a cell. In humans, the genome consists of 23 pairs of chromosomes (found in the nucleus), plus a small chromosome (found in the cells' mitochondria).</p> <span class="credit">image ©Darryl Leja, NHGRI</span> </figcaption> </figure> </div> <p>In <a href="http://www.visionlearning.com/en/library/Biology/2/Population-Genetics/249">Population Genetics: An Introduction</a> we discussed that <mark class="term" data-term="genetic drift" data-term-def="Changes in gene frequencies due to random events, such as when a small group is isolated from the rest of the&hellip;" data-term-url="/en/glossary/view/genetic+drift/11401">genetic drift</mark>, <mark class="term" data-term="gene" data-term-def="Material (usually DNA) that is inherited from a parent and which encodes for a cellular component important for some cellular function." data-term-url="/en/glossary/view/gene/3294">gene</mark> flow, <mark class="term" data-term="mutation" data-term-def="A change in gene sequences of cell DNA." data-term-url="/en/glossary/view/mutation/8757">mutation</mark>, and <mark class="term" data-term="natural selection" data-term-def="The process whereby characteristics that promote survival and reproduction are passed on to future generations, so these characteristics become more frequent&hellip;" data-term-url="/en/glossary/view/natural+selection/11402">natural selection</mark> all are forces of <mark class="term" data-term="evolution" data-term-def="Change in the gene pool of a population from generation to generation by such processes as mutation, natural selection, and genetic drift." data-term-url="/en/glossary/view/evolution/5284">evolution</mark> that interact to shape the <mark class="term" data-term="genome" data-term-def="All of the genetic material of an organism, carried in its DNA." data-term-url="/en/glossary/view/genome/8517">genomes</mark> of <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">populations</mark>. But how does one uncover the influence of these forces in sexually reproducing <mark class="term" data-term="species" data-term-def="1. In biological classifications, it is the lowest and most basic unit of the Linnaean taxonomic hierarchy (although it is also&hellip;" data-term-url="/en/glossary/view/species/893">species</mark>, such as humans, whose genes gets shuffled each generation? In our module <a href="/library/module_viewer.php?mid=145">Mendel and Independent Assortment</a> we discussed how genes sort independently as they are passed down from <mark class="term" data-term="generation" data-term-def="Offspring at the same step in the line of descent from a common ancestor." data-term-url="/en/glossary/view/generation/8293">generation</mark> to generation. This is due to recombination of segments of <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> that transfer, or crossover, during <mark class="term" data-term="meiosis" data-term-def="Process, occurring in sexually reproducing eukaryotes, in which a single cell divides twice, yielding four cells, also called gametes, each of&hellip;" data-term-url="/en/glossary/view/meiosis/10187">meiosis</mark> between homologous <mark class="term" data-term="chromosome" data-term-def="The organized genetic structure of DNA with associated proteins that contains the hereditary information necessary for reproduction, protein manufacture, and other functions." data-term-url="/en/glossary/view/chromosome/3760">chromosomes</mark> (similar, but not identical chromosomes, one <mark class="term" data-term="inherited" data-term-def="Passed down from one generation to another generation." data-term-url="/en/glossary/view/inherited/8738">inherited</mark> from the father and one from the mother). Think of a deck of cards nicely organized with hearts, spades, diamonds, and clubs each grouped together at first. Once shuffled, everything is all mixed up. The same thing happens with genetic recombination and if you attempt to track a certain <mark class="term" data-term="trait" data-term-def="A specific characteristic that is genetically determined." data-term-url="/en/glossary/view/trait/8271">trait</mark> backward more than a couple generations, you’ll have a very difficult time, considering how many ancestors there are to consider.</p><p>But not all of our <mark class="term" data-term="gene" data-term-def="Material (usually DNA) that is inherited from a parent and which encodes for a cellular component important for some cellular function." data-term-url="/en/glossary/view/gene/3294">genes</mark> get shuffled in the way that Mendel described in his pea plant <mark class="term" data-term="experiment" data-term-def="A test or trial carried out under controlled conditions so that specific actions can be performed and the results can be observed." data-term-url="/en/glossary/view/experiment/8292">experiments</mark>. In addition to gene shuffling, a Mendelian force, there are non-Mendelian means by which genetic <mark class="term" data-term="trait" data-term-def="A specific characteristic that is genetically determined." data-term-url="/en/glossary/view/trait/8271">traits</mark> can be passed down through <mark class="term" data-term="generation" data-term-def="Offspring at the same step in the line of descent from a common ancestor." data-term-url="/en/glossary/view/generation/8293">generations</mark>. <mark class="term" data-term="genetic drift" data-term-def="Changes in gene frequencies due to random events, such as when a small group is isolated from the rest of the&hellip;" data-term-url="/en/glossary/view/genetic+drift/11401">Genetic drift</mark> (which we emphasized in our <a href="http://www.visionlearning.com/en/library/Biology/2/Population-Genetics/249">Population Genetics: An Introduction</a> module) is one example, but there are other non-Mendelian phenomena. These include <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark>, genetic sequences that we inherit from only one <mark class="term" data-term="parent" data-term-def="The material or source from which something is derived." data-term-url="/en/glossary/view/parent/1618">parent</mark>, which allows us to solve our problems with tracking genetic traits and ancestry backward through time and geography.</p> <div class="comprehension-checkpoint margin-y-4"> <h6 class="comprehension-checkpoint__header"> <span> <span class="icon icon-question"></span> </span> Comprehension Checkpoint </h6> <form class="" name="cc11362"> <div class="form-entry"> <div class="form-entry__field"> <span class="form-entry__field__label">All genetic material is shuffled in a manner described by Gregor Mendel.</span> <div class="form-entry__option"> <div class="form-entry__option__radio" data-answer="incorrect"> <label> <input id="q1-11362-0-option-a" name="quiz-option-11362" type="radio" value="True" > <span class="option__label"> <span class="screen-reader-only">a.</span> True </span> </label> <span class="quiz__response" id="response-11362-0"> <strong>Incorrect.</strong> </span> </div> <div class="form-entry__option__radio" data-answer="correct"> <label> <input id="q1-11362-1-option-b" name="quiz-option-11362" type="radio" value="False" > <span class="option__label"> <span class="screen-reader-only">b.</span> False </span> </label> <span class="quiz__response" id="response-11362-1"> <strong>Correct!</strong> </span> </div> </div> </div> </div> </form> </div> <p><section id="toc_1" class=""> <h2>Tracking history with the Y-chromosome</h2></p> <p>William Sanchez of Albuquerque, New Mexico, was fascinated with genealogy and so had his <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> tested in 2001. Certain customs in his family made him ponder his ancestors who had been colonists in Mexico nearly a half millennium before his birth. He knew they had come from Spain, but there were things that his family did that anthropologists would call ‘crypto-Jewish’. They lit candles on Friday nights, covered mirrors when people died, and did several other things that as a boy Sanchez had assumed were normal for a Spanish-speaking Roman Catholic family in the Southwestern United States.</p><p>At age 52, though, he knew better, so when he got a call from a scientist at the genetic testing company, he was pretty sure they were going to tell him that he had some Jewish ancestry. Spain, after all, had expelled its Jewish <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">population</mark> in 1492, except for those agreeing to convert to Christianity. Some had converted but had continued their Jewish practices in secret, and many had fled Spain for the Americas. It therefore seemed plausible that some genetic sequences common in Jews might be part of his <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark>.</p><p>Sanchez was puzzled when the scientist on the phone told him that the testing showed he had genetic sequences of priests. Poetically, it was fitting: Sanchez actually was a priest –a Catholic priest, but it didn’t actually make sense.</p><p>"I mean that you’re a Kohane," the scientist explained. "You share ancestry with the Jewish priesthood." The company was telling Sanchez that he had a genetic marker that was patrilineal – passed down from father to son, because it was a Y-chromosome <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotype</mark> – and identifiable because it was carried by people with a particular historical role in Jewish culture.</p></section> <section id="toc2_1"><h3>Y-chromosome haplotypes</h3><p>Haplotypes are genetic sequences that we inherit from only one <mark class="term" data-term="parent" data-term-def="The material or source from which something is derived." data-term-url="/en/glossary/view/parent/1618">parent</mark>. This is different from autosomal <mark class="term" data-term="gene" data-term-def="Material (usually DNA) that is inherited from a parent and which encodes for a cellular component important for some cellular function." data-term-url="/en/glossary/view/gene/3294">genes</mark>, which are genes on a numbered <mark class="term" data-term="chromosome" data-term-def="The organized genetic structure of DNA with associated proteins that contains the hereditary information necessary for reproduction, protein manufacture, and other functions." data-term-url="/en/glossary/view/chromosome/3760">chromosome</mark> and usually affect males and females in similar ways. Although a small portion of the Y-chromosome has homology, or similarity of genes at the same place, with a region of the X-chromosome, where crossing over can occur between a dozen or so genes, the rest of the Y-chromosome is unique and non-homologous. It is passed down purely from father to son with no recombination. In this way, it is like a surname in many cultures, or for that matter like the Jewish priesthood: passed down from father to son.</p><p>While Y-chromosome <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark> are <mark class="term" data-term="inherited" data-term-def="Passed down from one generation to another generation." data-term-url="/en/glossary/view/inherited/8738">inherited</mark> as single genetic units without shuffling, they are subject to random <mark class="term" data-term="mutation" data-term-def="A change in gene sequences of cell DNA." data-term-url="/en/glossary/view/mutation/8757">mutation</mark>, just like the rest of the <mark class="term" data-term="genome" data-term-def="All of the genetic material of an organism, carried in its DNA." data-term-url="/en/glossary/view/genome/8517">genome</mark>. Harmful mutations are weeded out of the <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">population</mark> through <mark class="term" data-term="natural selection" data-term-def="The process whereby characteristics that promote survival and reproduction are passed on to future generations, so these characteristics become more frequent&hellip;" data-term-url="/en/glossary/view/natural+selection/11402">natural selections</mark>, but many mutations can stick around. For example, natural selection does not eliminate mutations that occur in an intron (a non-coding region of a gene) or in non-coding regions between <mark class="term" data-term="gene" data-term-def="Material (usually DNA) that is inherited from a parent and which encodes for a cellular component important for some cellular function." data-term-url="/en/glossary/view/gene/3294">genes</mark>.</p><p>The <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> polymerase <mark class="term" data-term="enzyme" data-term-def="Molecules produced by living organisms that help catalyze biochemical reactions. Enzymes are predominantly protein or protein-based molecules and are highly&hellip;" data-term-url="/en/glossary/view/enzyme/1595">enzyme</mark> is extremely efficient, so random <mark class="term" data-term="mutation" data-term-def="A change in gene sequences of cell DNA." data-term-url="/en/glossary/view/mutation/8757">mutation</mark> is rare. On average, it happens only once per hundred million base pairs of DNA per <mark class="term" data-term="generation" data-term-def="Offspring at the same step in the line of descent from a common ancestor." data-term-url="/en/glossary/view/generation/8293">generation</mark>. Knowing this rate, we can use mutations in <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark> as a kind of molecular clock. Based on the amount of variation in <mark class="term" data-term="haplotype" data-term-url="/en/glossary/view/haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;">haplotypes</mark> in different people, scientists can produce family trees estimating the common ancestry of those people.</p></section> <section id="toc2_2"><h3>Y-chromosome family tree</h3><p>In the mid-1990s, the discovery of numerous Y-chromosome <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark> enabled scientists to start building a Y-chromosome family tree, consisting of various branches all stemming back to a common trunk representing the common ancestor of all Y-chromosome <mark class="term" data-term="haplotype" data-term-url="/en/glossary/view/haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;">haplotypes</mark> (Figure 2). This common ancestor is called Y-MRCA, for "most recent common ancestor." This is sometimes called the Y-chromosome Adam, and it tracks back to 200,000 – 300,000 years ago.</p> <div class="figure"> <figure> <button class="lightbox-button lightbox-button--icon" data-lightbox="" data-lightbox-src="/img/library/large_images/image_11355.jpg"> <img src="/img/library/modules/mid248/Image/VLObject-11355-170312040335.jpg" alt="Figure 2: This family tree traces various branches all stemming back to a common ancestor of all Y-chromosome haplotypes. This common ancestor is called Y-MRCA, for "most recent common ancestor," or Y-chromosome Adam." /> </button> <figcaption> <p><strong>Figure 2</strong>: This family tree traces various branches all stemming back to a common ancestor of all Y-chromosome haplotypes. This common ancestor is called Y-MRCA, for "most recent common ancestor," or Y-chromosome Adam.</p> </figcaption> </figure> </div> <p>It is important to note that, while all living men have a Y-chromosome that is descended from a single male living in the Pleistocene epoch, there were many other men living at that time and many of them also left many descendants. The Y-chromosome Adam is just the man that all living men have in common through our patrilineal ancestry. Plenty of Adam’s contemporaries also left many descendants, just not through a purely patrilineal line. </p><p>In 1997, researchers in Haifa, Israel, and Toronto, Canada applied the same principles to test the claims that the Jewish priesthood began with a single man who lived more than 3,000 years ago. Among <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> from Jewish men from many different countries, the researchers identified two sequences, or markers, that were much more common in Jewish priests (Kohanim; singular Kohane) compared with Jews in general. A year later, the team identified four additional markers common in Kohanim, and they designated the six markers as the J1 Cohen Modal <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotype</mark>.</p><p>The Cohen Modal <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotype</mark> is found in both Ashkenazi and Sephardi Jews, the two largest Jewish <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">populations</mark>. It also exists among non-Jewish whose ancestry is in the Middle East, but there are great differences in frequencies of the six different markers that comprise the haplotype. Notably, the two markers that the team identified initially (called YAP and DYS19) were found to be present in 55 percent of Kohanim. The rate differed among Ashkenazi and Sephardi populations, the two main Jewish populations; 58 percent of Sephardi Kohanim showed the markers versus 48 percent of their Ashkenazi counterparts. But the rates in non-Kohanic Jews and in non-Jews were found to be much lower, meaning that Kohanim represented a distinct population, stemming from a common Y-chromosomal ancestor.</p><p>By comparing the Kohanic markers of the J1 Cohen <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotype</mark> to other Y-chromosome <mark class="term" data-term="haplotype" data-term-url="/en/glossary/view/haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;">haplotypes</mark>, researchers were able to place Jewish priests on the Y-chromosome family tree. This allowed them to date the common ancestor for the Kohanic priests of both Ashkenazi and Sephardi Jewish <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">populations</mark> to 2,400 to 3,000 years ago (Figure 3).</p> <div class="figure"> <figure> <button class="lightbox-button lightbox-button--icon" data-lightbox="" data-lightbox-src="/img/library/large_images/image_11354.jpg"> <img src="/img/library/modules/mid248/Image/VLObject-11354-170311060332.jpg" alt="Figure 3: A haplotype tree diagram of the Kohanim population's Y-chromosomal family tree." /> </button> <figcaption> <p><strong>Figure 3</strong>: A haplotype tree diagram of the Kohanim population's Y-chromosomal family tree.</p> <span class="credit">image ©Chriscohen</span> </figcaption> </figure> </div> <p>Sanchez was told he was a priest because he had the Cohen Modal <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotype</mark>, but perhaps more surprising is that the same haplotype was also found among the priests of the Lemba tribe in Zimbabwe, South Africa, Mozambique, and Malawi. The Lemba had always claimed to be part of the Jewish People, but anthropologists had been dismissing the idea for over a century. When molecular geneticists tested the Lemba priestly class called the Buba in the early 2000s, not only did they harbor the Cohen Modal haplotype, they carried it at a rate of 65 percent. They were Kohanim, with a patrilineal line even more pure than that of the Kohanim of Ashkenazi and Sephardi Jews. That these African Jews more closely resemble their fellow Africans than they do their fellow Jews of Europe and the Middle East tells of the extensive intermarriage of the Jewish diaspora with local <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">populations</mark>. Despite this, the Jewish blood lines were maintained as revealed by their Y-chromosomes.</p> <div class="comprehension-checkpoint margin-y-4"> <h6 class="comprehension-checkpoint__header"> <span> <span class="icon icon-question"></span> </span> Comprehension Checkpoint </h6> <form class="" name="cc11363"> <div class="form-entry"> <div class="form-entry__field"> <span class="form-entry__field__label">_____ are genetic sequences that we inherit from only one parent.</span> <div class="form-entry__option"> <div class="form-entry__option__radio" data-answer="correct"> <label> <input id="q1-11363-0-option-a" name="quiz-option-11363" type="radio" value="Haplotypes" > <span class="option__label"> <span class="screen-reader-only">a.</span> Haplotypes </span> </label> <span class="quiz__response" id="response-11363-0"> <strong>Correct!</strong> </span> </div> <div class="form-entry__option__radio" data-answer="incorrect"> <label> <input id="q1-11363-1-option-b" name="quiz-option-11363" type="radio" value="Genes" > <span class="option__label"> <span class="screen-reader-only">b.</span> Genes </span> </label> <span class="quiz__response" id="response-11363-1"> <strong>Incorrect.</strong> </span> </div> </div> </div> </div> </form> </div> </section> <section id="toc_2"> <h2>Mitochondrial DNA</h2><p>The Kohanim are one of many groups whose ancestry can be studied based on the Y-chromosome. The same technique used by the Haifa/Toronto researchers has been applied to track ancestry of various <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">populations</mark> of Europe and Asia as well as Native American tribes going back thousands of years. Since the Y-MRCA dates back to at least 200,000, Y-haplotypes also have been used in studying the emergence of our very <mark class="term" data-term="species" data-term-def="1. In biological classifications, it is the lowest and most basic unit of the Linnaean taxonomic hierarchy (although it is also&hellip;" data-term-url="/en/glossary/view/species/893">species</mark>.</p><p>As useful as Y-chromosome <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark> are, they track male ancestors only. This has several limitations. For example, Y-chromosome ancestry would give the same result if a whole <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">population</mark> of peoples moved from one place to another or if just a small group of mostly males migrated to a new area and conquered and subjugated the population there. This is what happened throughout Latin America during the age of the conquistadors. Even among individuals with almost exclusively indigenous roots, Spanish last names abound and so do European Y-chromosomes. For this and other reasons, examining Y-chromosomes paints only a partial picture of human ancestry.</p><p>The genetics of the Jewish diaspora exemplifies this. Ashkenazi Jews share a biological heritage with non-Jewish <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">populations</mark> of central and eastern Europe, where the Ashkenazi population emerged. Sephardi Jews, on the other hand, resemble non-Jews of the geographic areas that were host to Sephardi populations (Spain, Portugal, Turkey, Greece), both in appearance and in the frequency of certain genetic diseases. The same is true of Jewish populations based in the Middle East, and the Lemba tribe in southeast Africa. The Lemba have dark skin just like all the other peoples in the area and share other genetic similarities to their compatriots in southeast Africa. The Y-chromosome <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark> of their priestly class, the Buba, is the exception and shows they have common ancestry with Ashkenazi, Sephardi, and other populations of Jews.</p><p>How can this mixed ancestry be sorted out? A possible answer comes from another category of <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark>, those found in mitochondrial <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> (mtDNA). </p></section> <section id="toc2_3"><h3>mtDNA haplotypes</h3><p>Mitochondria are <mark class="term" data-term="organelle" data-term-def="Structure or compartment within a cell that performs a specialized function such as respiration or photosynthesis. An organelle is analogous to&hellip;" data-term-url="/en/glossary/view/organelle/5281">organelles</mark> found in all <mark class="term" data-term="eukaryotic" data-term-def="Of cells with a nucleus and other organelles that are surrounded by lipid membranes" data-term-url="/en/glossary/view/eukaryotic/6539">eukaryotic</mark> <mark class="term" data-term="cell" data-term-def="The basic structural unit of all living things." data-term-url="/en/glossary/view/cell/8286">cells</mark> that assist in cellular <mark class="term" data-term="respiration" data-term-def="The physical and chemical processes by which an organism supplies its cells and tissues with the oxygen needed for metabolism and&hellip;" data-term-url="/en/glossary/view/respiration/2195">respiration</mark> and the <mark class="term" data-term="synthesis" data-term-def="The production of a chemical compound by combining simpler compounds or elements." data-term-url="/en/glossary/view/synthesis/8756">synthesis</mark> of <mark class="term" data-term="adenosine triphosphate" data-term-url="/en/glossary/view/adenosine+triphosphate" data-term-def="(ATP) Molecules that provide energy for important chemical reactions within the cell; the main energy currency of the cell.">ATP</mark>. Owing to their distant past as autonomous bacterial cells, <mark class="term" data-term="mitochondria" data-term-def="Organelles that convert energy from food molecules into ATP, the main energy currency inside cells." data-term-url="/en/glossary/view/mitochondria/6542">mitochondria</mark> have some of their own <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> which harbors <mark class="term" data-term="gene" data-term-def="Material (usually DNA) that is inherited from a parent and which encodes for a cellular component important for some cellular function." data-term-url="/en/glossary/view/gene/3294">genes</mark> essential to mitochondrial function (Figure 4). Mitochondria reproduce on their own within your cells, and you have quadrillions of them in your body, but not one of them is from your father. Whether you are male or female, all of your mitochondria come from your mother, your mother’s mother, your mother’s mother’s mother, and on and on, going back to the first <mark class="term" data-term="eukaryote" data-term-def="A single- or multi-cellular organism whose cells contain a distinct nucleus that encloses the organism's genetic material." data-term-url="/en/glossary/view/eukaryote/5297">eukaryotes</mark> some billion and a half years ago.</p> <div class="figure"> <figure> <button class="lightbox-button lightbox-button--icon" data-lightbox="" data-lightbox-src="/img/library/large_images/image_11356.jpg"> <img src="/img/library/modules/mid248/Image/VLObject-11356-170312040350.jpg" alt="Figure 4: Mitochondria are the “power suppliers” for the cell, generating most of the ATP used in cell processes through the conversion of nutrients into energy. Mitochondria, along with mitochondrial DNA (mtDNA), are passed from mother to offspring." /> </button> <figcaption> <p><strong>Figure 4</strong>: Mitochondria are the “power suppliers” for the cell, generating most of the ATP used in cell processes through the conversion of nutrients into energy. Mitochondria, along with mitochondrial DNA (mtDNA), are passed from mother to offspring.</p> <span class="credit">image ©NIH</span> </figcaption> </figure> </div> <p>Like the Y-chromosome, mitochondrial <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> exists as single-copy, not paired <mark class="term" data-term="allele" data-term-def="A variation of a genetic element, usually resulting in a distinct trait." data-term-url="/en/glossary/view/allele/3302">alleles</mark>. Because our maternally-inherited mtDNA is not recombined with other alleles from our fathers, it stays pure along matrilineal ancestry. Only the occasional <mark class="term" data-term="mutation" data-term-def="A change in gene sequences of cell DNA." data-term-url="/en/glossary/view/mutation/8757">mutation</mark> alters mtDNA <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark>. Also, like the Y-chromosome, some mutations that occur in mtDNA are not harmful but neutral. These kinds of neutral mutations give us the mtDNA <mark class="term" data-term="haplotype" data-term-url="/en/glossary/view/haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;">haplotypes</mark>, which are useful for tracking matriarchal ancestry.</p></section> <section id="toc2_4"><h3>mtDNA most recent common ancestor</h3><p>Just as the tree for Y-chromosome <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark> coalesce with the Y-MRCA, the mtDNA <mark class="term" data-term="haplotype" data-term-url="/en/glossary/view/haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;">haplotypes</mark> coalesce backward in time to a last common mitochondrial ancestor, sometimes called the mitochondrial Eve. We are all descended from so-called mitochondrial Eve in an unbroken line of mothers and daughters (Figure 5). (Remember, though, that we will also be descended from other women living during and even before the time of mitochondrial Eve. We just didn’t get their mitochondrial <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> because we are related to them through at least one male.) Scientists estimate that mitochondrial Eve lived between 100,000 and 200,000 years ago.</p> <div class="figure"> <figure> <button class="lightbox-button lightbox-button--icon" data-lightbox="" data-lightbox-src="/img/library/large_images/image_11353.png"> <img src="/img/library/modules/mid248/Image/VLObject-11353-170311060308.png" alt="Figure 5: The Mitochondrial Eve female-lineage. Here the black matrilineal line is descended from mtDNA matrilineal most recent common ancestor (MRCA)." /> </button> <figcaption> <p><strong>Figure 5</strong>: The Mitochondrial Eve female-lineage. Here the black matrilineal line is descended from mtDNA matrilineal most recent common ancestor (MRCA).</p> <span class="credit">image ©C. Rottensteiner</span> </figcaption> </figure> </div> <p>Bible stories aside, it is exceedingly unlikely that Y-chromosome Adam and mitochondrial Eve lived at the same time, let alone in the same place, and they were certainly not alone in the world. However, they were real living people that made their way in the African savannah of a bygone era, totally unaware of their impending genetic legacy.</p><p>When scientists study <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">populations</mark> of a given ethnic group, they generate one family tree based on the Y-chromosomes and another tree based on mtDNA found in that population. When they do this, the trees almost never coincide perfectly. This is because humans have not always moved around in families consisting of a father, a mother, and their children. Polygyny was common in many cultures prior to modern times, and, during both prehistorical and modern times, men have migrated to new places and took local women as mates. By studying both the Y-chromosomes and the mtDNA, we can get both sides of the story.</p><p>While the Y-chromosome reveals links between Ashkenazi, Sephardic, Middle Eastern, and Lemba Jewish <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">populations</mark>, the matriarchal <mark class="term" data-term="lineage" data-term-def="In organisms, lineage is the line of descent from an ancestor." data-term-url="/en/glossary/view/lineage/5291">lineage</mark> recorded in mtDNA tells another story. It turns out that the <mark class="term" data-term="mitochondria" data-term-def="Organelles that convert energy from food molecules into ATP, the main energy currency inside cells." data-term-url="/en/glossary/view/mitochondria/6542">mitochondria</mark> of most Ashkenazi Jews have their most recent common ancestry on the Italian peninsula around 2,000 years ago. Thus, the matriarchs of much of the Ashkenazi population were not Jewish. They were non-Jews (pagans or Christians) from the heart of the Roman Empire. Rather than being in conflict with the Y-chromosome studies, mtDNA merely adds a new dimension to the story of Jewish populations.</p><p>Piecing the genetic information together with what is known from scraps of historical record, what seems to have happened is that the Ashkenazi <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">population</mark> started with Jewish men of Middle Eastern <mark class="term" data-term="descent" data-term-def="Ancestry or heritage." data-term-url="/en/glossary/view/descent/8285">descent</mark> who traveled through the Roman Empire, perhaps because they were merchants, and took local wives. The same thing happened in Zimbabwe; Jewish men traveled there in ancient times, bringing their traditions along with their Y-chromosomes. Upon marrying with the Jewish men, the local women added African <mark class="term" data-term="gene" data-term-def="Material (usually DNA) that is inherited from a parent and which encodes for a cellular component important for some cellular function." data-term-url="/en/glossary/view/gene/3294">genes</mark> into the gene pool of the resulting mixed population.</p> <div class="comprehension-checkpoint margin-y-4"> <h6 class="comprehension-checkpoint__header"> <span> <span class="icon icon-question"></span> </span> Comprehension Checkpoint </h6> <form class="" name="cc11368"> <div class="form-entry"> <div class="form-entry__field"> <span class="form-entry__field__label">_____ were autonomous bacterial cells in their distant past, which is why they have some of their own DNA.</span> <div class="form-entry__option"> <div class="form-entry__option__radio" data-answer="incorrect"> <label> <input id="q1-11368-0-option-a" name="quiz-option-11368" type="radio" value="MRCA" > <span class="option__label"> <span class="screen-reader-only">a.</span> MRCA </span> </label> <span class="quiz__response" id="response-11368-0"> <strong>Incorrect.</strong> </span> </div> <div class="form-entry__option__radio" data-answer="correct"> <label> <input id="q1-11368-1-option-b" name="quiz-option-11368" type="radio" value="Mitochondria" > <span class="option__label"> <span class="screen-reader-only">b.</span> Mitochondria </span> </label> <span class="quiz__response" id="response-11368-1"> <strong>Correct!</strong> </span> </div> </div> </div> </div> </form> </div> </section> <section id="toc_3"> <h2>Haplotypes and early humans</h2><p>The same year that the Haifa and Toronto researchers published their findings on Y-chromosome <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark> in Kohanim, a mtDNA study was dominating the science news cycle. Applying techniques that were state of the art in the late 1990s, a team led by Swedish geneticist Svante Pääbo of the <mark class="term" data-term="Max Planck" data-term-def="Theoretical physicist, born in Kiel, Germany (1858–1947), who won the Nobel Prize in Physics in 1918 for his research on quantum&hellip;" data-term-url="/en/glossary/view/Planck%2C+Max/8894">Max Planck</mark> Institute was able to extract mtDNA from bones of a <mark class="term" data-term="Neanderthal" data-term-def="An extinct species of humans, <em>Homo neanderthalensis</em>, who lived from approximately 400,000 to 40,000 years ago" data-term-url="/en/glossary/view/Neanderthal/11407">Neanderthal</mark> specimen – actually, the original "Neanderthal man," unearthed in 1856 in the Neanderthal Valley in what is now Germany. Certain bone <mark class="term" data-term="cell" data-term-def="The basic structural unit of all living things." data-term-url="/en/glossary/view/cell/8286">cells</mark> can have multiple nuclei, but nuclei throughout bone are vastly outnumbered by <mark class="term" data-term="mitochondria" data-term-def="Organelles that convert energy from food molecules into ATP, the main energy currency inside cells." data-term-url="/en/glossary/view/mitochondria/6542">mitochondria</mark>. Thus, mtDNA is orders of <mark class="term" data-term="magnitude" data-term-def="Magnitude is a number assigned to a quantity and refers to the size or extent of something. There are several differing&hellip;" data-term-url="/en/glossary/view/magnitude/11226">magnitude</mark> more abundant than nuclear <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark>. Each cell has hundreds or thousands of copies of the same mitochondrial <mark class="term" data-term="chromosome" data-term-def="The organized genetic structure of DNA with associated proteins that contains the hereditary information necessary for reproduction, protein manufacture, and other functions." data-term-url="/en/glossary/view/chromosome/3760">chromosome</mark>, so Pääbo and his team knew that if they could get any useful DNA sequences, they’d be coming from mtDNA. That was already a tall order in 1997, whereas getting nuclear DNA from an ancient bone was considered science fiction.</p><p>After extracting <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> and amplifying it (making multiple copies of its sequence) through a technique called the polymerase chain reaction (PCR), the team went through a painstaking <mark class="term" data-term="process" data-term-def="Method, procedure; series of actions or steps." data-term-url="/en/glossary/view/process/8256">process</mark> of weeding out sequences belonging to different <mark class="term" data-term="species" data-term-def="1. In biological classifications, it is the lowest and most basic unit of the Linnaean taxonomic hierarchy (although it is also&hellip;" data-term-url="/en/glossary/view/species/893">species</mark> of <mark class="term" data-term="bacteria" data-term-def="(plural of bacterium) A large group of one-celled organisms that are found almost everywhere." data-term-url="/en/glossary/view/bacteria/8679">bacteria</mark> that came from the dirt. This left a tiny percentage of the sample; that was the mtDNA from the <mark class="term" data-term="Neanderthal" data-term-def="An extinct species of humans, <em>Homo neanderthalensis</em>, who lived from approximately 400,000 to 40,000 years ago" data-term-url="/en/glossary/view/Neanderthal/11407">Neanderthal</mark> individual to whom the bones had belonged.</p><p>Neanderthals were a <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">population</mark> of humans whose bones and tools indicate that they lived from about 300,000 years ago until about 30,000 years ago when they went <mark class="term" data-term="extinction" data-term-url="/en/glossary/view/extinction" data-term-def="The complete and permanent loss of all individuals of a species of organism.">extinct</mark>. They existed in parallel with our own <mark class="term" data-term="species" data-term-def="1. In biological classifications, it is the lowest and most basic unit of the Linnaean taxonomic hierarchy (although it is also&hellip;" data-term-url="/en/glossary/view/species/893">species</mark>, Homo sapiens sapiens (modern humans), and with other species of humans that also suffered <mark class="term" data-term="extinction" data-term-def="The complete and permanent loss of all individuals of a species of organism." data-term-url="/en/glossary/view/extinction/5615">extinction</mark>. A big question has always been whether <mark class="term" data-term="Neanderthal" data-term-def="An extinct species of humans, <em>Homo neanderthalensis</em>, who lived from approximately 400,000 to 40,000 years ago" data-term-url="/en/glossary/view/Neanderthal/11407">Neanderthals</mark> and modern humans interbred, or were reproductively isolated from one another. Using the mtDNA extracted and amplified from the Neanderthal specimens, Pääbo and his team were able to do <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotype</mark> <mark class="term" data-term="analysis" data-term-def="The careful study of data to look for patterns." data-term-url="/en/glossary/view/analysis/8553">analysis</mark> in comparison with mtDNA from present-day modern humans (Figure 6). The result showed a difference between Neanderthal mtDNA and modern human mtDNA greater than any difference between different branches of the modern human mtDNA family tree. In other words, Neanderthals did not descend from the mitochondrial Eve of modern humans. Instead, Neanderthals had their own mitochondrial Eve, which Pääbo’s analysis showed had lived a lot further into the past than our own mitochondrial Eve. This proved that Neanderthals did not contribute mtDNA to our line.</p> <div class="figure"> <figure> <button class="lightbox-button lightbox-button--icon" data-lightbox="" data-lightbox-src="/img/library/large_images/image_11357.jpg"> <img src="/img/library/modules/mid248/Image/VLObject-11357-170312060330.jpg" alt="Figure 6: Researchers extracted DNA from neanderthal bones, carefully ensuring it was not contaminated with DNA from any other source (like modern humans)." /> </button> <figcaption> <p><strong>Figure 6</strong>: Researchers extracted DNA from neanderthal bones, carefully ensuring it was not contaminated with DNA from any other source (like modern humans).</p> <span class="credit">image ©NHGRI</span> </figcaption> </figure> </div> <p>As discussed earlier, mtDNA reveals only one dimension of a population’s history, the <mark class="term" data-term="maternal" data-term-def="Derived from or related to one's mother." data-term-url="/en/glossary/view/maternal/5315">maternal</mark> side. However, in the late 1990s, retrieving nuclear <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> from bones that were more than 50,000 years old was thought to be impossible, and so mtDNA was thought to be all we would ever know of the genetics of our <mark class="term" data-term="Neanderthal" data-term-def="An extinct species of humans, <em>Homo neanderthalensis</em>, who lived from approximately 400,000 to 40,000 years ago" data-term-url="/en/glossary/view/Neanderthal/11407">Neanderthal</mark> cousins.</p><p>This changed with the advent of Next-generation in-solution <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> sequencing, often abbreviated "Next-gen sequencing," which became available just a few years after the mtDNA of <mark class="term" data-term="Neanderthal" data-term-def="An extinct species of humans, <em>Homo neanderthalensis</em>, who lived from approximately 400,000 to 40,000 years ago" data-term-url="/en/glossary/view/Neanderthal/11407">Neanderthals</mark> was published. With this far more sensitive technique, Pääbo and others were able to amplify and analyze the Y-chromosome <mark class="term" data-term="haplotype" data-term-def="Genetic sequences that we inherit from only one parent. Haplotypes include sequences from mitochondrial DNA (mtDNA) and the non-homologous portion of&hellip;" data-term-url="/en/glossary/view/haplotype/10181">haplotypes</mark> of Neanderthals and another <mark class="term" data-term="extinction" data-term-url="/en/glossary/view/extinction" data-term-def="The complete and permanent loss of all individuals of a species of organism.">extinct</mark> human subspecies, called the Denisovans. Similar to the Jewish story, the Y-chromosome and mtDNA family trees disagree in comparisons of modern humans with Neanderthals. In contrast to mtDNA, the Y-chromosomal <mark class="term" data-term="data" data-term-def="(plural form of <b>datum</b>) A collection of pieces of information, generally taking the form of numbers, text, bits, or facts, that&hellip;" data-term-url="/en/glossary/view/data/3729">data</mark> show instances of <mark class="term" data-term="gene" data-term-def="Material (usually DNA) that is inherited from a parent and which encodes for a cellular component important for some cellular function." data-term-url="/en/glossary/view/gene/3294">gene</mark> flow, interbreeding between modern humans and Neanderthals and other extinct human <mark class="term" data-term="species" data-term-def="1. In biological classifications, it is the lowest and most basic unit of the Linnaean taxonomic hierarchy (although it is also&hellip;" data-term-url="/en/glossary/view/species/893">species</mark> </p><p>We now have now sequenced a complete <mark class="term" data-term="Neanderthal" data-term-def="An extinct species of humans, <em>Homo neanderthalensis</em>, who lived from approximately 400,000 to 40,000 years ago" data-term-url="/en/glossary/view/Neanderthal/11407">Neanderthal</mark> <mark class="term" data-term="genome" data-term-def="All of the genetic material of an organism, carried in its DNA." data-term-url="/en/glossary/view/genome/8517">genome</mark>, completing the picture of their genetic ancestry and its relation to our own. It turns out that, while the modern human <mark class="term" data-term="lineage" data-term-def="In organisms, lineage is the line of descent from an ancestor." data-term-url="/en/glossary/view/lineage/5291">lineage</mark> diverged from the Neanderthal lineage about 500,000 years ago, and remained separate for most of that time, the two <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">populations</mark> exchanged <mark class="term" data-term="gene" data-term-def="Material (usually DNA) that is inherited from a parent and which encodes for a cellular component important for some cellular function." data-term-url="/en/glossary/view/gene/3294">genes</mark> on at least four occasions. Today, about 8 percent of the non-African human gene pool consists of Neanderthal DNA! Africans, however, do not have any detectable Neanderthal <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> in their genomes, indicating that the admixture took place only after humans had migrated out of Africa and encountered Neanderthals on the Eurasian continent.</p><p>Similar to the kohanim priests, the difference between mtDNA and nuclear <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> can be explained with scenarios in which the men migrated and interbred with women from other <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">populations</mark>. Many modern humans have some <mark class="term" data-term="Neanderthal" data-term-def="An extinct species of humans, <em>Homo neanderthalensis</em>, who lived from approximately 400,000 to 40,000 years ago" data-term-url="/en/glossary/view/Neanderthal/11407">Neanderthal</mark> or Denisovan forefathers, but not foremothers. Our mitochondrial line is more "pure," for lack of a better term, compared with the patrilineal lines and that is why scientists in the mid-1990s incorrectly deduced that modern humans had little or no genetic input from Neanderthals.</p> <div class="comprehension-checkpoint margin-y-4"> <h6 class="comprehension-checkpoint__header"> <span> <span class="icon icon-question"></span> </span> Comprehension Checkpoint </h6> <form class="" name="cc11369"> <div class="form-entry"> <div class="form-entry__field"> <span class="form-entry__field__label">Analysis of _____ shows that modern humans and neanderthals interbred at some point.</span> <div class="form-entry__option"> <div class="form-entry__option__radio" data-answer="correct"> <label> <input id="q1-11369-0-option-a" name="quiz-option-11369" type="radio" value="Y-chromosome haplotypes" > <span class="option__label"> <span class="screen-reader-only">a.</span> Y-chromosome haplotypes </span> </label> <span class="quiz__response" id="response-11369-0"> <strong>Correct!</strong> </span> </div> <div class="form-entry__option__radio" data-answer="incorrect"> <label> <input id="q1-11369-1-option-b" name="quiz-option-11369" type="radio" value="mtDNA haplotypes" > <span class="option__label"> <span class="screen-reader-only">b.</span> mtDNA haplotypes </span> </label> <span class="quiz__response" id="response-11369-1"> <strong>Incorrect.</strong> </span> </div> </div> </div> </div> </form> </div> </section> <section id="toc_4"> <h2>Back to the ancestry math problem</h2><p>At the beginning of this module, we explained how, if you double the number of ancestors you have in each preceding <mark class="term" data-term="generation" data-term-def="Offspring at the same step in the line of descent from a common ancestor." data-term-url="/en/glossary/view/generation/8293">generation</mark>, you only have to go back a few hundred years before, theoretically, the total number of ancestors you have is larger than the <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">population</mark> of the earth. This is obviously not possible. The math gets even stranger the further back you go. What is wrong with these calculations?</p><p>The answer is that, as you go back in your family tree, ancestors will start to pop up more than once. If you go back two <mark class="term" data-term="generation" data-term-def="Offspring at the same step in the line of descent from a common ancestor." data-term-url="/en/glossary/view/generation/8293">generations</mark> to your grandparents, you have four different ancestors. If you go back two more, you almost certainly have sixteen distinct ancestors. However, if you go back eight generations or about 200 years, the math would predict that you have 256 ancestors, but you almost certainly don’t. In fact, you may have closer to 200. This is because the farther back you go, the more "repeat" ancestors you will find. In fact, after 12-15 generations, the total number of your ancestors barely increases each additional generation that you go back.</p><p>This is a phenomenon known as “pedigree collapse,” in which distant relatives mate with each other creating a family tree in which an ancestor will appear in multiple places. In the royal families of Europe, the pedigrees collapse in the very recent past. For example, both Queen Elizabeth II and her consort, Prince Philip Mountbatten, are the great-grandchildren of Queen Victoria (Figure 7). In fact, if we want to trace Queen Elizabeth’s line all the way back to William the Conqueror, there are dozens of paths to choose from. But the rest of us can hardly poke fun. Our own family trees collapse quickly enough.</p> <div class="figure"> <figure> <button class="lightbox-button lightbox-button--icon" data-lightbox="" data-lightbox-src="/img/library/large_images/image_11359.jpg"> <img src="/img/library/modules/mid248/Image/VLObject-11359-170312070332.jpg" alt="Figure 7: This family tree shows how both Queen Elizabeth II and her husband, Prince Philip Mountbatten, are the great-grandchildren of Queen Victoria" /> </button> <figcaption> <p><strong>Figure 7</strong>: This family tree shows how both Queen Elizabeth II and her husband, Prince Philip Mountbatten, are the great-grandchildren of Queen Victoria</p> </figcaption> </figure> </div> <p>The sum of all this is that we are all related and probably a lot more closely than you think. In fact, scientists estimate that the most recent common ancestor of all humans lived just 2,000-3,000 years ago somewhere in the Levant or Northern Africa. This is different from Y-chromosome Adam or mitochondrial Eve, who gave rise to very specific <mark class="term" data-term="lineage" data-term-def="In organisms, lineage is the line of descent from an ancestor." data-term-url="/en/glossary/view/lineage/5291">lineages</mark> that then came to comprise the entire <mark class="term" data-term="population" data-term-def="In biology, the population is all individuals of a certain kind of plant or animal that live in a particular habitat.&hellip;" data-term-url="/en/glossary/view/population/8283">population</mark>. The most recent common ancestor (MRCA) is just someone who is in everyone’s family tree at least once, even though we can never know what, if any, genetic contribution is his because the <mark class="term" data-term="DNA" data-term-def="Deoxyribonucleic acid. A double-stranded nucleic acid containing the sugar 2-deoxy-D-ribose. A constituent of cellular nuclear material responsible for encoding&hellip;" data-term-url="/en/glossary/view/DNA/1604">DNA</mark> we <mark class="term" data-term="inherited" data-term-def="Passed down from one generation to another generation." data-term-url="/en/glossary/view/inherited/8738">inherited</mark> from our two <mark class="term" data-term="parent" data-term-def="The material or source from which something is derived." data-term-url="/en/glossary/view/parent/1618">parents</mark> becomes shuffled when we pass it down to the next <mark class="term" data-term="generation" data-term-def="Offspring at the same step in the line of descent from a common ancestor." data-term-url="/en/glossary/view/generation/8293">generation</mark>.</p><p>Nevertheless, every human alive today, from the Buma priests in Zimbabwe to native tribes on remote islands in the Pacific, all share this common ancestor. Of course, many other people living at that time left many, even millions of descendants, but only one of them, MRCA, is common to all of us.</p><p>So if anyone ever asks you, "Are you related to her?," there is only one correct answer: "yes."</p> </div> </section> <hr class="border-color-dark" /> <footer class="module__footer"> <p class="citation"> <em> David Warmflash, MD, Nathan H Lents, Ph.D. “Tracking Human Ancestry” Visionlearning Vol. BIO-5 (2), 2017. </em> </p>  <div class="title-list" name="further"> <p class="h6 title-list__title"> Further Reading </p> <ul class="grid grid--column-2--md grid--column-3--md gap-1"> <li> <a class="no-hover-focus height-100" href="/en/library/Biology/2/Gene-Expression/214"> <article class="flex-row align-items-center flex-column--md align-items-start--md height-100 theme-light padding-2 gap-2"> <div class="width-30 width-auto--md"> <img class="border-radius box-shadow-1" src="/img/library/moduleImages/featured_image_214-23061209063659.jpg" alt="Gene Expression"> </div> <div class="flex-grow-shrink"> <h2 class="h6 font-weight-normal"> Gene Expression: <em>Enzymes and hereditary conditions</em> </h2> </div> </article> </a> </li> <li> <a class="no-hover-focus height-100" href="/en/library/Biology/2/Population-Genetics/249"> <article class="flex-row align-items-center flex-column--md align-items-start--md height-100 theme-light padding-2 gap-2"> <div class="width-30 width-auto--md"> <img class="border-radius box-shadow-1" src="/img/library/moduleImages/featured_image_249-23061209063739.jpeg" alt="Population Genetics"> </div> <div class="flex-grow-shrink"> <h2 class="h6 font-weight-normal"> Population Genetics: <em>Hardy-Weinberg and genetic drift</em> </h2> </div> </article> </a> </li> </ul> </div> </footer> </div>   </div>  <div class="order-1 order-2--lg module__tools"> <div class="narrow margin-x-auto position-sticky-top font-size-md"> <div class="padding-2 border-radius box-shadow-1--lg"> <div class="tabs" role="tablist"> <nav> <button class="button button--icon-label" id="tab-button-in-this-module" aria-label="Table of Contents" aria-controls="tab-panel-module__tools" aria-selected="true" role="tab"> <span class="icon icon-list" aria-hidden="true"></span> <span class="button__text">Contents</span> </button> <button class="button button--icon-label" id="tab-button-toggle-terms" aria-controls="tab-panel-toggle-terms" aria-selected="false" role="tab"> <span class="icon icon-glossary-highlight"></span> <span class="button__text">Glossary Terms</span> </button> </nav> <hr class="divider" /> <div class="tabs__panel shown" id="tab-panel-module__tools" aria-labelledby="tab-button-module__tools" role="tabpanel"> <p class="font-weight-bold margin-bottom-1"> Table of Contents </p> <div class="table-of-contents" id="module-toc"> <ul> <li><a href="/en/library/biology/2/tracking-human-ancestry/248#toc_1">Tracking history with the Y-chromosome</a> </li> <li> <ul> <li><a href="/en/library/biology/2/tracking-human-ancestry/248#toc2_1">Y-chromosome haplotypes</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/biology/2/tracking-human-ancestry/248#toc2_2">Y-chromosome family tree</a> </li> </ul> </li> <li><a href="/en/library/biology/2/tracking-human-ancestry/248#toc_2">Mitochondrial DNA</a> </li> <li> <ul> <li><a href="/en/library/biology/2/tracking-human-ancestry/248#toc2_3">mtDNA haplotypes</a> </li> </ul> </li> <li> <ul> <li><a href="/en/library/biology/2/tracking-human-ancestry/248#toc2_4">mtDNA most recent common ancestor</a> </li> </ul> </li> <li><a href="/en/library/biology/2/tracking-human-ancestry/248#toc_3">Haplotypes and early humans</a> </li> <li><a href="/en/library/biology/2/tracking-human-ancestry/248#toc_4">Back to the ancestry math problem</a> </li> </ul> </div> </div>   <div class="tabs__panel" id="tab-panel-toggle-terms" aria-labelledby="tab-button-toggle-terms" role="tabpanel"> <div class="reading-toggle"> <div class="reading-toggle__switch"> <div class="form-entry__option__switch"> <label> <input type="checkbox" name="termsToggleSwitch" id="terms-toggle-switch" /> <span class="switch__slider"></span> <span class="option__label text-decoration-none font-size-md"> Highlight Glossary Terms </span> </label> </div> </div> <div class="reading-toggle__help"> <p> <em> Activate glossary term highlighting to easily identify key terms within the module. Once highlighted, you can click on these terms to view their definitions. </em> </p> </div> </div> </div> <div class="tabs__panel" id="tab-panel-toggle-ngss" aria-labelledby="tab-button-toggle-ngss" role="tabpanel"> <div class="reading-toggle"> <div class="reading-toggle__switch"> <div class="form-entry__option__switch"> <label> <input type="checkbox" name="ngssToggleSwitch" id="ngss-toggle-switch" /> <span class="switch__slider"></span> <span class="option__label text-decoration-none font-size-md"> Show NGSS Annotations </span> </label> </div> </div> <div class="reading-toggle__help"> <p> <em> Activate NGSS annotations to easily identify NGSS standards within the module. 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Tracking Human Ancestry | Biology | Visionlearning