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<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /> <title>Hugo de Vries :: DNA from the Beginning</title> <meta name="description" content="Biography of Hugo de Vries from Concept 6: Genes are real things, DNA from the Beginning" /> <link rel="preload" as="style" src="/css/main.css"> <link rel="preload" as="script" src="/js/swfobject.js"> <link rel="preload" as="script" src="/js/prototype-1.6.1.js"> <link href="/css/main.css" rel="stylesheet" type="text/css" /> <link href='https://fonts.googleapis.com/css?family=Droid+Serif' rel='stylesheet' type='text/css'/> <link href='https://fonts.googleapis.com/css?family=Droid+Sans' rel='stylesheet' type='text/css'/> <script type="text/javascript" src="/js/swfobject.js"></script> <script type="text/javascript" src="/js/prototype-1.6.1.js"></script> </head> <body> <div id="container"> <div id="content"> <div id="header"> <div class="rollover-home"> <a href="/" class="rollover-home" title="DNA from the Beginning Home"><span class="displace">Home</span></a> </div> </div>  <div id="content-container"> <h1><span> Concept 6</span> Genes are real things.</h1> <div id="nav"> <ul> <li class="menu1"><a href="index.html" title="CONCEPT" ><span class="displace">CONCEPT</span></a></li> <li class="menu2"><a href="animation.html" title="ANIMATION"><span class="displace">ANIMATION</span></a></li> <li class="menu3"><a href="gallery.html" title="GALLERY"><span class="displace">GALLERY</span></a></li> <li class="menu4"><a href="av.html" title="VIDEO"><span class="displace">VIDEO</span></a></li> <li class="menu5"><a href="bio.html" title="BIO"><span class="displace">BIO</span></a></li> <li class="menu6"><a href="problem.html" title="PROBLEM"><span class="displace">PROBLEM</span></a></li> <li class="menu7"><a href="links.html" title="LINKS" ><span class="displace">LINKS</span></a></li> </ul> <br class="clearfloat" /> </div> <div id="bio" > <p> <a href="/6/bio.html"><img src="/images/6/bio_de_vries_thumb.jpg" alt="Hugo de Vries" class="floatLeft"/></a> <a href="/6/bio-2.html"><img src="/images/6/bio_correns_thumb.jpg" alt="Carl Correns" class="floatLeft" /></a> <a href="/6/bio-3.html"><img src="/images/6/bio_tschermak_seysenegg_thumb.jpg" alt="Erich von Tschermak-Seysenegg" class="floatLeft" /></a> <a href="/6/bio-4.html"><img src="/images/6/bio_hooke_thumb.jpg" alt="Robert Hooke" class="floatLeft" /></a> <a href="/6/bio-5.html"><img src="/images/6/bio_schwann_thumb.jpg" alt="Theodor Schwann" class="floatLeft" /></a> <a href="/6/bio.html">Hugo de Vries</a>, <a href="/6/bio-2.html">Carl Correns</a> and <a href="/6/bio-3.html">Erich von Tschermak-Seysenegg</a> were the three scientists who rediscovered Mendel's laws in 1900. They were all working independently on different plant hybrids, and came to the same conclusions about inheritance as Mendel. <a href="/6/bio-4.html">Robert Hooke</a> was one of the first scientists to describe a cell. <a href="/6/bio-5.html">Theodor Schwann</a> redefined the cell as a living unit.<br class="clearfloat" /></p> <div id="people-list"> <ul> <li><span class="small">Go to:</span></li> <li><a href="/6/bio-2.html">Carl Erich Correns (1864-1933)</a></li> <li><a href="/6/bio-3.html">Erich von Tschermak (1871-1962)</a></li> <li><a href="/6/bio-4.html">Robert Hooke (1635-1703)</a></li> <li><a href="/6/bio-5.html">Theodor Schwann (1810-1882)</a></li> </ul> </div> <div class="bio-current4"> <h2>Hugo de Vries (1848-1935)</h2> </div> <br class="clearfloat" /> <div id="border"></div> <img src="/images/6/6bio.gif" alt="Hugo de Vries" class="floatRight" /> <p>Hugo de Vries was born in Haarlem, Netherlands. He was a Professor of Botany at the <a href = "http://www.uva.nl/english/index.html"> University of Amsterdam</a> when he began his genetic experiments with plants in 1880. He completed most of his hybridization experiments without knowing about Mendel's work. Based on his own results, de Vries drew the same conclusions as Mendel. De Vries published his work in 1900, first in French then in German. In the French report there was no mention of Mendel, but this was amended by de Vries in the German paper. It is possible that de Vries read Mendel's paper before he published his own, and included Mendel's name in the later printing when he realized that other people also knew about Mendel's work. De Vries may have thought that his own conclusions were superior to Mendel's. </p> <p>De Vries was also a strong proponent of the idea of discontinuous variations. De Vries believed species evolve from other species through sudden, large changes of character traits. De Vries based this "theory of mutation" on work he did using <a href = "http://www.bio.uva.nl/propedeuse2000/data/algemeen/hugo/wetensch.htm"> <i>Oenothera lamarckiana</i></a> — the evening primrose. He observed that the original plant would occasionally have offspring with significant phenotypic differences such as leaf shape and plant sizes. Some of the offspring would pass the new "sport" (mutation) to their progeny; these de Vries designated as new species. </p> <p>It is now known that de Vries had the right idea, but for the wrong reasons. Most of the variants that de Vries isolated from <i>Oenothera lamarckiana</i> were due to aberrant chromosomal segregations, and not to mutations associated with specific genes.</p> <div id="factoid-bio"> <img src="/images/general/factoid.gif" alt="factoid" class="factoid-image" /> <img src="/images/general/didyouknow.jpg" alt="Did you know ?" /> <p>Theodor Schwann recognized that eggs, ova, are cells. In 1841, sperm were classified as cells when they were seen developing from testis cells.</p> <img src="/images/general/hmmm.jpg" alt="Hmmm..." /> <p>What is the largest single cell in existence?</p> </div>  </p> </div> </div> <br class="clearfloat" /> <div id="footer"> <ul> <li><a href="/">Home</a></li> <li><a href="/sitemap.html">Site Map</a></li> <li><a href="/scientists.html">Scientists</a></li> <li><a href="/glossary.html">Glossary</a></li> <li><a href="/feedback.html">Feedback</a></li> <li><a href="/awards.html">Awards</a></li> <li><a href="/credits.html">Credits</a></li> <li><a href="http://blogs.dnalc.org/dnaftb/" style="background-image:none;">Blog</a></li> </ul> <p> Funded by <a href="http://macyfoundation.org">The Josiah Macy, Jr. Foundation</a><br /> © 2002 - 2011, <a href="http://www.dnalc.org/"> DNA Learning Center</a>, <a href="https://www.cshl.edu/">Cold Spring Harbor Laboratory</a>. All rights reserved. </p> </div>  </div> <div id="sidebar"> <div id="search" > <form method="get" action="/search"> <div class="fieldHolder1"> <input type="search" id="q" name="q" placeholder="Search" onclick="this.value=''" value="" /> <img style="background-color:#9C0;" src="/images/general/search_icon.jpg" alt="Search" onclick="document.forms[0].submit()" /> </div> </form> </div>  <div id="sidebar"> <ul class="sections-side sections-side1a" style="padding-top: 56px; margin-top: 3px;"> <li ><a href="/1/"><img src="/images/thumbnails/1-thumb-sm.png" alt="1." />Children resemble their parents.</a></li> <li ><a href="/2/"><img src="/images/thumbnails/2-thumb-sm.png" alt="2." />Genes come in pairs.</a></li> <li ><a href="/3/"><img src="/images/thumbnails/3-thumb-sm.png" alt="3." />Genes don't blend.</a></li> <li ><a href="/4/"><img src="/images/thumbnails/4-thumb-sm.png" alt="4." />Some genes are dominant.</a></li> <li ><a href="/5/"><img src="/images/thumbnails/5-thumb-sm.png" alt="5." />Genetic inheritance follows rules.</a></li> <li ><a class="concept-highlight" href="/6/"><img src="/images/thumbnails/6-thumb-sm.png" alt="6." />Genes are real things.</a></li> <li ><a href="/7/"><img src="/images/thumbnails/7-thumb-sm.png" alt="7." />All cells arise from pre-existing cells.</a></li> <li ><a href="/8/"><img src="/images/thumbnails/8-thumb-sm.png" alt="8." />Sex cells have one set of chromosomes; body cells have two.</a></li> <li ><a href="/9/"><img src="/images/thumbnails/9-thumb-sm.png" alt="9." />Specialized chromosomes determine sex.</a></li> <li ><a href="/10/"><img src="/images/thumbnails/10-thumb-sm.png" alt="10." />Chromosomes carry genes.</a></li> <li ><a href="/11/"><img src="/images/thumbnails/11-thumb-sm.png" alt="11." />Genes get shuffled when chromosomes exchange pieces.</a></li> <li ><a href="/12/"><img src="/images/thumbnails/12-thumb-sm.png" alt="12." />Evolution begins with the inheritance of gene variations.</a></li> <li ><a href="/13/"><img src="/images/thumbnails/13-thumb-sm.png" alt="13." />Mendelian laws apply to human beings.</a></li> <li style="border-bottom: 1px solid #669;"><a href="/14/"><img src="/images/thumbnails/14-thumb-sm.png" alt="14." />Mendelian genetics cannot fully explain human health and behavior.</a></li> </ul> <ul class="menu-side"> <li class="section2"><a href="/15/index.html" title="Molecules of Genetics"><span class="displace">MOLECULES OF GENETICS</span></a></li> <li class="section3" ><a href="/29/index.html" title="Genetic Organization and Control"><span class="displace">GENETIC ORGANIZATION AND CONTROL</span></a></li> </ul> </div> </div>  <br class="clearfloat" /> </div>  <script type="text/javascript"> Event.observe(window, 'load', function() { var uri = '/6/bio.html'; uri = uri.replace(/-\d/,''); $('nav').down().descendants().each(function(s) { if (s.nodeName == 'A') { if (s.href.match(uri)) { s.addClassName('current'); throw $break; } } }); }); </script> <script type="text/javascript"> var _gaq = _gaq || []; _gaq.push(['_setAccount', 'UA-1818773-10']); _gaq.push(['_trackPageview']); (function() { var ga = document.createElement('script'); ga.type = 'text/javascript'; ga.async = true; ga.src = 'https://www.google-analytics.com/ga.js'; var s = document.getElementsByTagName('script')[0]; s.parentNode.insertBefore(ga, s); })(); </script>  <script async src="https://www.googletagmanager.com/gtag/js?id=G-K6EHFCRJBP"></script> <script> window.dataLayer = window.dataLayer || []; function gtag(){dataLayer.push(arguments);} gtag('js', new Date()); gtag('config', 'G-K6EHFCRJBP'); </script> </body> </html>