Species | Definition, Types, & Examples

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text-black link-blue" href="https://www.britannica.com/science/species-taxon">species</a> </div> <button aria-label="Close" class="js-sections-close-button btn-link btn-sm btn d-lg-none position-absolute top-0 p-10 right-0" > <em class="material-icons font-26" data-icon="close"></em> </button> </div> <div class="section-content pl-10 pr-20 pl-sm-50 pr-sm-60 pl-lg-5 pr-lg-10 pt-10 pt-lg-0 bg-gray-50 clear-catfish-ad"> <div class="toc mb-20"> <div class="font-serif font-14 font-weight-bold mx-15 mb-15 mt-20"> Table of Contents </div> <ul class="list-unstyled my-0" data-level="h1"><li data-target="#ref1"><div class="pl-25"><a class="link-gray-900 w-100" href="/science/species-taxon">Introduction</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref281258"><div class="d-flex align-items-center"><div class="ml-25"></div><a class="w-100 link-gray-900" href="/science/species-taxon#ref281258">Taxonomy</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref281259"><div class="d-flex align-items-center"><div class="ml-25"></div><a class="w-100 link-gray-900" href="/science/species-taxon/Speciation">Speciation</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li><li data-target="#ref281260"><div class="d-flex align-items-center"><div class="ml-25"></div><a class="w-100 link-gray-900" href="/science/species-taxon/Speciation#ref281260">Identifying and cataloging species</a></div><div class="ml-40 toc-drawer sub-toc-drawer"></div></li></ul> <a class="toc-extra-link link-gray-900" href="https://www.britannica.com/science/species-taxon/additional-info">References & Edit History</a> <a class="toc-extra-link link-gray-900" href="/facts/species-taxon">Related Topics</a> </div> <div class="tlr-media-slider pb-10 mb-30"> <a class="section-header link-gray-900 font-serif font-14 font-weight-bold mb-10 mx-10" href="https://www.britannica.com/science/species-taxon/images-videos">Images & 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Gittleman</div> <div class="editor-description font-12 font-serif mt-5 clamp-description text-black">Dean of the graduate faculty at the University of Georgia's Odum School of Ecology. Editor of <em>Carnivore Behavior, Ecology, and Evolution</em>; co-editor of <em>Carnivore Conservation</em>.</div> </a> <div data-popper-arrow></div> </div> <span class="btn btn-link editor-link p-0 qa-byline-link gtm-byline font-12 byline-contributor text-decoration-underline"> John L. 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They write new content and verify and edit content received from contributors.</div> </a> <div data-popper-arrow></div> </div> <span class="btn btn-link editor-link p-0 qa-byline-link font-12 "> The Editors of Encyclopaedia Britannica</span></div> <div class="last-updated font-12 font-serif"> <span class="text-gray-700"> Last Updated: <time datetime="2024-10-30T00:00:00CDT" >Oct 30, 2024</time> •</span> <a class="byline-edit-history" href="https://www.britannica.com/science/species-taxon/additional-info#history" rel="nofollow">Article History</a> </div></div> </div> <button class="d-flex d-lg-none btn btn-outline-blue border rounded-sm shadow-sm mobile-toc-button gtm-mobile-toc-inline-button d-none d-sm-block js-sections-inline-button module-spacing btn d-lg-none"> <em class="material-icons mr-5 ml-n10 my-n5 md-icon" data-icon="toc"></em> Table of Contents </button> <div class="d-flex d-sm-none flex-row"> <button class="d-flex d-lg-none btn btn-outline-blue border rounded-sm shadow-sm mobile-toc-button gtm-mobile-toc-inline-button js-sections-inline-button module-spacing"> <em class="material-icons mr-5 ml-n10 my-n5 md-icon" data-icon="toc"></em> Table of Contents </button> <button class="ai-ask-button btn border-2 ai-ask-button btn border-2 module-spacing btn-sm js-inline-ai-ask-button btn-outline-red-400 border-red-400 p-10 ml-5"> Ask the Chatbot a Question </button> </div> <div class="js-qf-module qf-module px-40 px-sm-20 py-15 mx-auto module-spacing font-14 bg-gray-50 rounded"> <div class="facts-list mt-10"> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Key People: </dt> <dd><a href="/biography/John-Ray-English-naturalist" topicid="492392">John Ray</a></dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> </div> <div class=""> <div class="js-fact mb-10 line-clamp clamp-3"> <dl> <dt>Related Topics: </dt> <dd><a href="/science/pioneer-species" topicid="663430">pioneer species</a></dd> <dd><a href="/science/endemic-species" topicid="1307542">endemic species</a></dd> <dd><a href="/science/r-selected-species" topicid="487821">r-selected species</a></dd> <dd><a href="/science/eusocial-species" topicid="1512491">eusocial species</a></dd> <dd><a href="/science/K-selected-species" topicid="309092">K-selected species</a></dd> </dl> <button class="js-more-btn d-none btn btn-unstyled font-12 bg-gray-50" aria-label="Toggle more/less fact data"> <em class="js-content link-blue">(Show more)</em> </button> </div> <div class="text-center"> <a class="btn btn-sm btn-link p-0" href="/facts/species-taxon"> See all related content </a> </div> </div> </div> </div><span class="marker before-article"></span><section data-level="1" id="ref1"><span class="marker PREMOD1 mod-inline"></span><p class="topic-paragraph"><strong><span id="ref76048"></span>species</strong>, in <a href="https://www.britannica.com/science/biology" class="md-crosslink " data-show-preview="true">biology</a>, <a href="https://www.britannica.com/science/classification-biology" class="md-crosslink autoxref " data-show-preview="true">classification</a> <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="comprising" href="https://www.merriam-webster.com/dictionary/comprising" data-type="MW">comprising</a> related organisms that share common characteristics and are capable of <span id="ref76052"></span><a href="https://www.britannica.com/science/interbreeding" class="md-crosslink ">interbreeding</a>. This biological species concept is widely used in biology and related fields of study. There are more than 20 other different species concepts, however. Some examples include the ecological species concept, which describes a species as a group of organisms framed by the resources they depend on (in other words, their <a href="https://www.britannica.com/science/niche-ecology" class="md-crosslink " data-show-preview="true">ecological niche</a>), and the genetic species concept, which considers all organisms capable of inheriting <a href="https://www.britannica.com/science/character-biology" class="md-crosslink " data-show-preview="true">traits</a> from one another within a common <a href="https://www.britannica.com/science/gene-pool" class="md-crosslink " data-show-preview="true">gene pool</a> and the amount of genetic difference between <a href="https://www.britannica.com/science/population-biology-and-anthropology" class="md-crosslink " data-show-preview="true">populations</a> of that species. Like the biological species concept, the genetic species concept considers which individuals are capable of interbreeding, as well as the amount of genetic difference between populations of that species, but it may also be used to estimate when the species originated.</p><span class="marker MOD1 mod-inline"></span></section> <span class="marker h2"></span><section data-level="1" id="ref281258"><h2 class="h1">Taxonomy</h2> <span class="marker PREMOD2 mod-inline"></span><div class="assemblies multiple medialist slider js-slider position-relative d-inline-flex align-items-center mw-100" data-type="other"><div class="slider-container js-slider-container overflow-hidden d-flex"><div class="rw-track d-flex align-items-center"><div class="position-relative rw-slide col-100 px-20 "><figure class="md-assembly m-0 mb-md-0 card card-borderless print-false" data-assembly-id="148663" data-asm-type="image"><div class="md-assembly-wrapper card-media " data-type="image"><a href="https://cdn.britannica.com/78/103778-050-D797CF4F/Animals-groups-organisms-succession-general-particular.jpg" class="gtm-assembly-link position-relative d-flex align-items-center justify-content-center media-overlay-link card-media" data-href="/media/1/558649/148663"><picture><source media="(min-width: 680px)" srcset="https://cdn.britannica.com/78/103778-050-D797CF4F/Animals-groups-organisms-succession-general-particular.jpg"><img src="https://cdn.britannica.com/78/103778-050-D797CF4F/Animals-groups-organisms-succession-general-particular.jpg?w=300" alt="animal taxonomy" data-width="1600" data-height="1524" loading="eager"></picture><div class="position-absolute top-10 left-10 assembly-slide-tag rounded-lg">1 of 3</div><button class="magnifying-glass btn btn-circle position-absolute shadow btn-white top-10 right-10" aria-label="Zoom in"><em class="material-icons link-blue" data-icon="zoom_in"></em></button></a></div><figcaption class="card-body"><div class="md-assembly-caption text-muted font-14 font-serif line-clamp"><span><a class="gtm-assembly-link md-assembly-title font-weight-bold d-inline font-sans-serif mr-5 media-overlay-link" href="https://cdn.britannica.com/78/103778-050-D797CF4F/Animals-groups-organisms-succession-general-particular.jpg" data-href="/media/1/558649/148663">animal taxonomy</a><span>Animals and other organisms are classified within a succession of nested groups that ranges from the general to the particular.</span><button class="js-more-btn d-none btn btn-unstyled font-12 bg-white js-content" aria-label="Toggle more/less fact data"><span class="link-blue">(more)</span></button></span></div></figcaption></figure></div><div class="position-relative rw-slide col-100 px-20 "><figure class="md-assembly m-0 mb-md-0 card card-borderless print-false" data-assembly-id="8026" data-asm-type="image"><div class="md-assembly-wrapper card-media " data-type="image"><a href="https://cdn.britannica.com/07/5207-050-5BC9F251/Gray-wolf.jpg" class="gtm-assembly-link position-relative d-flex align-items-center justify-content-center media-overlay-link card-media" data-href="/media/1/558649/8026"><picture><source media="(min-width: 680px)" srcset="https://cdn.britannica.com/07/5207-050-5BC9F251/Gray-wolf.jpg?w=300"><img src="https://cdn.britannica.com/07/5207-050-5BC9F251/Gray-wolf.jpg?w=300" alt="gray wolf" data-width="918" data-height="608" loading="eager"></picture><div class="position-absolute top-10 left-10 assembly-slide-tag rounded-lg">2 of 3</div><button class="magnifying-glass btn btn-circle position-absolute shadow btn-white top-10 right-10" aria-label="Zoom in"><em class="material-icons link-blue" data-icon="zoom_in"></em></button></a></div><figcaption class="card-body"><div class="md-assembly-caption text-muted font-14 font-serif line-clamp"><span><a class="gtm-assembly-link md-assembly-title font-weight-bold d-inline font-sans-serif mr-5 media-overlay-link" href="https://cdn.britannica.com/07/5207-050-5BC9F251/Gray-wolf.jpg" data-href="/media/1/558649/8026">gray wolf</a><span>Gray wolf (<em>Canis lupus</em>).</span><button class="js-more-btn d-none btn btn-unstyled font-12 bg-white js-content" aria-label="Toggle more/less fact data"><span class="link-blue">(more)</span></button></span></div></figcaption></figure></div><div class="position-relative rw-slide col-100 px-20 "><figure class="md-assembly m-0 mb-md-0 card card-borderless print-false" data-assembly-id="119646" data-asm-type="image"><div class="md-assembly-wrapper card-media " data-type="image"><a href="https://cdn.britannica.com/45/125545-050-B705597E/Coyote.jpg" class="gtm-assembly-link position-relative d-flex align-items-center justify-content-center media-overlay-link card-media" data-href="/media/1/558649/119646"><picture><source media="(min-width: 680px)" srcset="https://cdn.britannica.com/45/125545-050-B705597E/Coyote.jpg?w=300"><img src="https://cdn.britannica.com/45/125545-050-B705597E/Coyote.jpg?w=300" alt="coyote" data-width="1600" data-height="1182" loading="eager"></picture><div class="position-absolute top-10 left-10 assembly-slide-tag rounded-lg">3 of 3</div><button class="magnifying-glass btn btn-circle position-absolute shadow btn-white top-10 right-10" aria-label="Zoom in"><em class="material-icons link-blue" data-icon="zoom_in"></em></button></a></div><figcaption class="card-body"><div class="md-assembly-caption text-muted font-14 font-serif line-clamp"><span><a class="gtm-assembly-link md-assembly-title font-weight-bold d-inline font-sans-serif mr-5 media-overlay-link" href="https://cdn.britannica.com/45/125545-050-B705597E/Coyote.jpg" data-href="/media/1/558649/119646">coyote</a><span>Coyote (<em>Canis latrans</em>).</span><button class="js-more-btn d-none btn btn-unstyled font-12 bg-white js-content" aria-label="Toggle more/less fact data"><span class="link-blue">(more)</span></button></span></div></figcaption></figure></div></div></div><button disabled="true" class="prev-button js-prev-button position-absolute btn btn-circle shadow btn-lg btn-blue-dark m-20"><span class="material-icons" data-icon="keyboard_arrow_left"></span></button><button disabled="true" class="next-button js-next-button position-absolute btn btn-circle shadow btn-lg btn-blue-dark m-20"><span class="material-icons" data-icon="keyboard_arrow_right"></span></button></div><p class="topic-paragraph">The <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="designation" href="https://www.merriam-webster.com/dictionary/designation" data-type="MW">designation</a> of species originates in <span id="ref1264504"></span><a href="https://www.britannica.com/science/taxonomy" class="md-crosslink " data-show-preview="true">taxonomy</a>, where the species is the fundamental unit of classification recognized by the International Commission of Zoological <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="Nomenclature" href="https://www.merriam-webster.com/dictionary/Nomenclature" data-type="MW">Nomenclature</a>. Every species is assigned a standard two-part name of <span id="ref76050"></span><a href="https://www.britannica.com/science/genus-taxon" class="md-crosslink " data-show-preview="true">genus</a> and species. The genus is the generic name that includes closely related species; the gray <a href="https://www.britannica.com/animal/wolf" class="md-crosslink " data-show-preview="true">wolf</a>, for example, is classified as <em>Canis lupus</em> and is a close relative of the <a href="https://www.britannica.com/animal/coyote-mammal" class="md-crosslink " data-show-preview="true">coyote</a> found in <a href="https://www.britannica.com/place/North-America" class="md-crosslink " data-show-preview="true">North America</a> and designated as <em>Canis latrans</em>, their systematic relation indicated by their sharing the same genus name, <em>Canis</em>. Similarly, genera that have shared <a href="https://www.britannica.com/science/character-biology" class="md-crosslink " data-show-preview="true">characters</a> (or traits) are classified in the same taxonomic family; related families are placed in the same order; related orders are placed in the same class; and related classes are placed in the same phylum. This classification system is a <a class="md-dictionary-link md-dictionary-tt-off mw" data-term="hierarchy" href="https://www.merriam-webster.com/dictionary/hierarchy" data-type="MW">hierarchy</a> applied to all animals and plants, as originally set forth by the Swedish naturalist <span id="ref1264505"></span><a href="https://www.britannica.com/biography/Carolus-Linnaeus" class="md-crosslink " data-show-preview="true">Carolus Linnaeus</a> in the 18th century.</p><span class="marker MOD2 mod-inline"></span> <span class="marker PREMOD3 mod-inline"></span><p class="topic-paragraph">Organisms are grouped into species partly according to their <a href="https://www.britannica.com/science/morphology-biology" class="md-crosslink " data-show-preview="true">morphological</a>, or external, similarities, but more important in classifying sexually reproducing organisms is the organisms’ ability to successfully interbreed. Individuals of a single species can mate and produce viable offspring with one another but almost never with members of other species. Separate species have been known to produce hybrid offspring (for example, the <a href="https://www.britannica.com/animal/horse" class="md-crosslink " data-show-preview="true">horse</a> and the <a href="https://www.britannica.com/animal/donkey" class="md-crosslink " data-show-preview="true">donkey</a> producing the <a href="https://www.britannica.com/animal/mule-mammal" class="md-crosslink " data-show-preview="true">mule</a>), but, because the <a class="md-dictionary-link md-dictionary-tt-off eb" data-term="offspring" href="https://www.britannica.com/dictionary/offspring" data-type="EB">offspring</a> are almost always inviable or sterile, the interbreeding is not considered successful.</p><div class="one-good-fact-module"> </div><span class="marker MOD3 mod-inline"></span> <span class="marker PREMOD4 mod-inline"></span><p class="topic-paragraph">Interbreeding only within the species is of great importance for evolution in that individuals of one species share a common <a href="https://www.britannica.com/science/gene" class="md-crosslink " data-show-preview="true">gene</a> <span id="ref1029742"></span><a href="https://www.britannica.com/science/gene-pool" class="md-crosslink " data-show-preview="true">pool</a> that members of other species do not. Within a single pool there is always a certain amount of <a href="https://www.britannica.com/science/variation-biology" class="md-crosslink " data-show-preview="true">variation</a> among individuals, and those whose genetic variations leave them at a disadvantage in a particular <a href="https://www.britannica.com/science/environment" class="md-crosslink " data-show-preview="true">environment</a> tend to be eliminated in favour of those with advantageous variations. This process of <span id="ref76055"></span><a href="https://www.britannica.com/science/natural-selection" class="md-crosslink " data-show-preview="true">natural selection</a> results in the gene pool’s evolving in such a way that the advantageous variations become the norm. Because genetic variations originate in individuals of a species and because those individuals pass on their variations only within the species, then it is at the species level that evolution takes place. The <a href="https://www.britannica.com/science/evolution-scientific-theory" class="md-crosslink " data-show-preview="true">evolution</a> of one species into others is called <a href="https://www.britannica.com/science/speciation" class="md-crosslink " data-show-preview="true">speciation</a>.</p><span class="marker MOD4 mod-inline"></span></section> <span class="marker end-of-content"></span><span class="marker after-article"></span></div> <div id="chatbot-root"></div> </div> </div> </div> <div class="ai-dialog-placeholder"></div> </div> </div> <aside class="col-md-da-320"></aside> </div> </div> </div> </div> </article></div> </div></div> </div> </main> <div id="md-footer"></div> <noscript><iframe src="//www.googletagmanager.com/ns.html?id=GTM-5W6NC8" height="0" width="0" style="display:none;visibility:hidden"></iframe></noscript> <script type="text/javascript" id="_informizely_script_tag"> var IzWidget = IzWidget || {}; (function (d) { var scriptElement = d.createElement('script'); scriptElement.type = 'text/javascript'; scriptElement.async = true; scriptElement.src = "https://insitez.blob.core.windows.net/site/f780f33e-a610-4ac2-af81-3eb184037547.js"; var node = d.getElementById('_informizely_script_tag'); node.parentNode.insertBefore(scriptElement, node); } )(document); </script>  <script> window.ap3c = window.ap3c || {}; var ap3c = window.ap3c; ap3c.cmd = ap3c.cmd || []; ap3c.cmd.push(function() { ap3c.init('ZO4siT4cLwnykPnzZWJtd3Byb2Q', 'https://engage.email.britannica.com/'); ap3c.track({v: 0}); }); ap3c.activity = function(act) { ap3c.act = (ap3c.act || []); ap3c.act.push(act); }; var s, t; s = document.createElement('script'); s.type = 'text/javascript'; s.src = "https://engage.email.britannica.com/app.js"; t = document.getElementsByTagName('script')[0]; t.parentNode.insertBefore(s, t); </script> <script class="marketing-page-info" type="application/json"> {"pageType":"Topic","templateName":"DESKTOP","pageNumber":1,"pagesTotal":2,"pageId":558649,"pageLength":547,"initialLoad":true,"lastPageOfScroll":false} </script> <script class="marketing-content-info" type="application/json"> [] </script> <script src="https://cdn.britannica.com/mendel-resources/3-130/js/libs/jquery-3.5.0.min.js?v=3.130.14"></script> <script type="text/javascript" data-type="Init Mendel Code Splitting"> (function() { $.ajax({ dataType: 'script', cache: true, url: 'https://cdn.britannica.com/mendel-resources/3-130/dist/topic-page.js?v=3.130.14' }); })(); </script> <script class="analytics-metadata" type="application/json"> {"leg":"A","adLeg":"A","userType":"ANONYMOUS","pageType":"Topic","pageSubtype":null,"articleTemplateType":"PAGINATED","gisted":false,"pageNumber":1,"hasSummarizeButton":false,"hasAskButton":false} </script> <script type="text/javascript"> EBStat={accountId:-1,hostnameOverride:'webstats.eb.com',domain:'www.britannica.com', json:''}; </script> <script type="text/javascript"> ( function() { $.ajax( { dataType: 'script', cache: true, url: '//www.britannica.com/webstats/mendelstats.js?v=1' } ) .done( function() { try {writeStat(null,EBStat);} catch(err){} } ); })(); </script> <div id="bc-fixed-dialogue"></div> </body> </html>

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Species | Definition, Types, & Examples | Britannica