Micro- and macroevolution (Interested)

<body text="#000000" bgcolor="#FFFFFF"><script language="JavaScript"></script><table border=0 cellspacing=0 cellpadding=0 width=840 style="table-layout:fixed"> <colgroup><col width=118><col width=562><col width=160></colgroup> <tr> <td rowspan=4 valign="top" style="text-align:right;"><a name="0"></a><img src="../grafik/fg_u_103.gif" vspace=2 width=97 height=75 border=0 alt="Evolution: Biology - Micro- and macroevolution"></td> <td colspan=2 height=26> </td> </tr> <tr> <td colspan=2 height=26 class="kopfzeile"> <h1><a target="main" href="https://www.genesisnet.info/artikel/artikel.php?Sprache=en&Artikel=40000">Evolution: Biology</a></h1> </td> </tr> <tr><td colspan=2><img src="s.gif" width=1 height=2 border=0 alt="evolution, creation"></td></tr> <tr><td><h2><i>Basic Ideas: </i>Micro- and macroevolution</h2></td> <td valign="top" bgcolor="#E6E6E6"> <div class="muiep" style="padding-top:4px;"><a target="main" href="https://www.genesisnet.info/artikel/artikel.php?l=0&Artikel=41220&Sprache=en"><img src="../grafik/1_pfeil_grau.gif" width=9 height=9 border=0 alt="evolution, creation"> Overview </a></div> </td> </tr> </table> <table border=0 cellspacing=0 cellpadding=0 width=840> <colgroup><col width=680><col width=160></colgroup> <tr> <td colspan=2><img src="s.gif" width=1 height=2 border=0 alt="evolution, creation"></td> </tr> <tr> <td><h3 style="padding-top:16px;">Content</h3> <P>In evolutionary research the terms of microevolution and macroevolution are often used. These terms are explained. Unfortunately they are not used uniformly. The opinions differ concerning the question whether or not there is a fundamental difference between microevolution and macroevolution.</P><p><a href="#1"><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> Microevolution</a></p> <p><a href="#3"><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> Macroevolution</a></p> <p><a href="#5"><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> An attempt at distinction</a></p> <p><a href="#6"><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> A lot of microevolution = macroevolution?</a></p> <p><a href="#7"><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> Arguments for the equivalence of both terms</a></p> <p><a href="#8"><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> Polyvalence and macroevolution</a></p> <p><a href="https://www.genesisnet.info/artikel/interessierte_druck.php?Sprache=en&Artikel=41223" target=_blank><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> Show a printer-friendly version of this page   <img src="../grafik/drucker.gif" width="14" height="14" border="0" style="vertical-align:middle;" alt="evolution, creation"></a></p> </td> <td class=rb> </td> </tr> </table> <table border=0 cellspacing=0 cellpadding=0 width="840"> <colgroup><col width="680"><col width="160"></colgroup><tr><td valign="top"><img src="s.gif" width="680" height="1" border="0" alt="evolution, creation"><h3><a name="1"></a>Microevolution</h3> </td> <td class=rb> </td></tr> <tr><td valign="top"><P>Two very important terms in evolutionary research are <B>microevolution</B> and <B>macroevolution</B>.</P></td> <td valign="top" class=rb> </td></tr> </table> <table border=0 cellspacing=0 cellpadding=0 width="840"> <colgroup><col width="680"><col width="160"></colgroup><tr><td valign="top"><img src="s.gif" width="680" height="1" border="0" alt="evolution, creation"><div class=textbild><a href="../bild.php?Sprache=en&ID=26" onclick="return Bild_Anzeigen('../bild.php?ID=26&Sprache=en',400,136);"><img src="../bilder/bild_26_en" width=400 height=129 border=0 alt="Fig. 26: Micro- and macroevolution (Zum Vergrößern anklicken)"><br>Fig. 26: Characteristics of microevolution and macroevolution</a></div></td> <td class=rb> </td></tr> <tr><td valign="top"><P><B>Microevolution</B> means variation founded on already existing constructions, for instance specialization on certain environmental factors, optimization of single features (for instance the size of grain seed) or their degeneration. Microevolution could be described as variation on a theme, process of optimization or as survival strategy.</P></td> <td valign="top" class=rb> </td></tr> </table> <table border=0 cellspacing=0 cellpadding=0 width="840"> <colgroup><col width="680"><col width="160"></colgroup><tr><td valign="top"><img src="s.gif" width="680" height="1" border="0" alt="evolution, creation"><p style="padding-bottom:3px;text-align:right;"><a href="#0"><img src="../grafik/evo_top.gif" width=31 height=10 border=0 alt="evolution, creation"></a></p><h3 style="padding-bottom:4px;"><a name="3"></a>Macroevolution</h3> </td> <td class=rb> </td></tr> <tr><td valign="top"><P>On the other hand <B>macroevolution</B> means the formation of new constructions - and in the end formation of new blueprints (see fig. 257).</P> <P>An example will illustrate the difference between microevolution and macroevolution: Microevolution would be the variety of the form of bird beaks (see fig. 258). While one beak may be short and massive (good for cracking hard seeds) the other may be long and thin (good for poking insects in the bark of trees).</P> <P>On the other hand macroevolution means the formation of the same beak out of the toothed jawbone of a forerunner reptile. For this purpose conversion would be necessary in several respects, conversion that would not be achieved by simple variation (thicker, thinner, longer, shorter).  A beak is made up of different material than teeth, the muscular system and ingestional behavior (provision, motion) have to be adapted, beak and jawbone are differently anchored in the skull and so on.</P></td> <td rowspan=2 valign="top" class=rb><div class=bild><a href="../bild.php?Sprache=en&ID=258" onclick="return Bild_Anzeigen('../bild.php?ID=258&Sprache=en',460,600);"><img src="../bilder/bild_258_k" width=138 height=179 border=1 alt="Fig. 258: Microevolu- tionary variation (Click to magnify)" class=rb><br>Fig. 258: Microevolu-<br> tionary variation</a></div> </td></tr> <tr><td valign="top"><img src="s.gif" width="680" height="1" border="0" alt="evolution, creation"><div class=textbild><a href="../bild.php?Sprache=en&ID=257" onclick="return Bild_Anzeigen('../bild.php?ID=257&Sprache=en',738,600);"><img src="../bilder/bild_257" width=492 height=400 border=0 alt="Fig. 257: Micro- and Macroevolution (Zum Vergrößern anklicken)"><br>Fig. 257: left: Macroevolution across the board of basic types;<br> right: Microevolution within the basic types</a></div></td> </tr> </table> <table border=0 cellspacing=0 cellpadding=0 width="840"> <colgroup><col width="680"><col width="160"></colgroup><tr><td valign="top"><img src="s.gif" width="680" height="1" border="0" alt="evolution, creation"><p style="padding-bottom:3px;text-align:right;"><a href="#0"><img src="../grafik/evo_top.gif" width=31 height=10 border=0 alt="evolution, creation"></a></p><h3 style="padding-bottom:4px;"><a name="5"></a>An attempt at distinction</h3> </td> <td class=rb> </td></tr> <tr><td valign="top"><P>As in the example of the bird beak it is mostly easy to indicate whether a change from A to B is of microevolutionary or macroevolutionary nature. Nevertheless there are examples where a differentiation is more difficult or even impossible without closer examination. Is the acquisition of a new enzymatic function by a protein microevolution or macroevolution? Can the acquisition of poison resistance already be called macroevolution? To answer these questions a deeper knowledge of metabolism and genetics is required. Here studies of the isolated case will give an answer.</P> <P>These examples of grey areas however do not challenge the unquestionable cases of a clear differentiability between microevolution and macroevolution. Although a sharp line between both terms cannot (yet?) be drawn precisely in every aspect, a distinction between the two terms is still useful, because they both represent different problems to be solved. Typical of a macroevolutional transition is the <B>necessity of many independent yet matching changes</B> that have to be achieved to get a new functioning structure. It is possible to quantify the problem of “macroevolution” in the molecular field.</P></td> <td valign="top" class=rb> </td></tr> </table> <table border=0 cellspacing=0 cellpadding=0 width="840"> <colgroup><col width="680"><col width="160"></colgroup><tr><td valign="top"><img src="s.gif" width="680" height="1" border="0" alt="evolution, creation"><p style="padding-bottom:3px;text-align:right;"><a href="#0"><img src="../grafik/evo_top.gif" width=31 height=10 border=0 alt="evolution, creation"></a></p><h3 style="padding-bottom:4px;"><a name="6"></a>A lot of microevolution = macroevolution?</h3> </td> <td class=rb> </td></tr> <tr><td valign="top"><P>It is often challenged that there is a fundamental difference between microevolution and macroevolution. A lot of microevolution would then inevitably be macroevolution. This claim is often made without any appropriate argument. The qualitative equation of both terms neglects the fact that they are connected to totally different types of problems.</P></td> <td valign="top" class=rb> </td></tr> </table> <table border=0 cellspacing=0 cellpadding=0 width="840"> <colgroup><col width="680"><col width="160"></colgroup><tr><td valign="top"><img src="s.gif" width="680" height="1" border="0" alt="evolution, creation"><p style="padding-bottom:3px;text-align:right;"><a href="#0"><img src="../grafik/evo_top.gif" width=31 height=10 border=0 alt="evolution, creation"></a></p><h3 style="padding-bottom:4px;"><a name="7"></a>Arguments for the equivalence of both terms</h3> </td> <td class=rb> </td></tr> <tr><td valign="top"><UL> <LI>Whatever does not happen within a short period of time might be possible within a longer period. This argument lacks substance. For an explanation we fall back on the bird beak: Ever so much variation of the beak does not give any hint on its origin. Time does not matter in this question. The availability of time is no argument for the possibility of macroevolution. <LI>Sometimes it is suggested that there are no hints on special mechanisms for macroevolution. Then a differentiation between microevolution and macroevolution would be out of place. This suggestion does not hit the question of distinguishing microevolution and macroevolution – it could as well mean that macroevolution never occurred. The fact that no special macroevolutionary mechanisms were found can therefore not be taken as a proof that microevolutionary processes are sufficient for macroevolution. <LI>Even the application of the principle that present events can be extrapolated to understand past events only allows the conclusion that the evolutional processes of the past took course in microevolutionary limits as well.</LI></UL></td> <td valign="top" class=rb> </td></tr> </table> <table border=0 cellspacing=0 cellpadding=0 width="840"> <colgroup><col width="680"><col width="160"></colgroup><tr><td valign="top"><img src="s.gif" width="680" height="1" border="0" alt="evolution, creation"><p style="padding-bottom:3px;text-align:right;"><a href="#0"><img src="../grafik/evo_top.gif" width=31 height=10 border=0 alt="evolution, creation"></a></p><h3 style="padding-bottom:4px;"><a name="8"></a>Polyvalence and macroevolution</h3> </td> <td class=rb> </td></tr> <tr><td valign="top"><P>Macroevolutionary changes can possibly be simulated if a species has the ability to develop certain features only if required. Biologists speak of “latent genetic potencies” – hidden abilities in the genome. Daphnias for instance can change their outer form enormously depending on the amount of salt in the water. This and other examples are known for a long time and named “<B>modifications</B>”. Every now and then abilities of living beings are found that were unknown until then and now occur as quasi “new feature”. These cases are no example for macroevolution because the features already existed before within the genome. The ability for modification is much more a sign of already existing polyvalence of living beings.</P></td> <td valign="top" class=rb> </td></tr> </table> <table border=0 cellspacing=0 cellpadding=0 width="840"> <colgroup><col width="680"><col width="160"></colgroup><tr><td valign="top"><img src="s.gif" width="680" height="1" border="0" alt="evolution, creation"><p><br>Translator: Sarah Aziz, 07.01.2008</p><p><a href="https://www.genesisnet.info/intern/mitarbeiter.php?Sprache=en&ID=18&Artikel=41223" target=main><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> Information about the translator</a></p><p><a href="https://www.genesisnet.info/kontakt/email.php?Sprache=en&Autor=18&Artikel=41223" target=main><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> Email to the translator</a></p><p><br>Author: Reinhard Junker</p><p><a href="https://www.genesisnet.info/intern/mitarbeiter.php?Sprache=en&ID=3&Artikel=41223" target=main><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> Information about the author</a></p><hr size=1 color="#CCCCCC" style="margin-top:20px;margin-left:128px;margin-right:30px;"><p style="margin-bottom:0px;margin-top:10px;"><a href="https://www.genesisnet.info/artikel/interessierte_druck.php?Sprache=en&Artikel=41223" target="_blank"><img src="../grafik/1_pfeil_weiss.gif" width=9 height=9 border=0 style="vertical-align:middle;" alt="evolution, creation"> Show a printer-friendly version of this page   <img src="../grafik/drucker.gif" width="14" height="14" border="0" style="vertical-align:middle;" alt="evolution, creation"></a></p><hr size=1 color="#CCCCCC" style="margin-left:128px;margin-right:30px;"><p style="padding-top:7px;">Set a <a target=_top href="https://www.genesisnet.info/dateien_en/i41223_micro__and_macroevolution.php" onclick="if (navigator.userAgent.toLowerCase().indexOf('msie')>-1) {window.external.AddFavorite('https://www.genesisnet.info/index.php?Sprache=en&Artikel=41223&l=1','Genesisnet - Micro- and macroevolution (Level: Basic Ideas)');} else {alert('Unfortunately this browser does not support this function.\n\nPlease click this link again with the RIGHT mouse button and select the appropriat entry of the context menu.');} return false;">bookmark (favorite)</a> on this page or send the location <a href="mailto:@?body=https://www.genesisnet.info/dateien_en/i41223_micro__and_macroevolution.php">by email</a>.</p><p style="color:#666666;white-space:break-word"> <br>© 2008, https://www.genesisnet.info/dateien_en/i41223.php</p></td> <td valign="top" class=rb> </td></tr> </table> </body>