Why for some animals, sex is worth waiting for

<body leftmargin="0" bgcolor="#000060" text="#FFFFFF" link="#FFFF00" vlink="#FF9900"> <b> <p class="MsoNormal"><font face="Arial" size="4">Why for some animals, sex is worth waiting for</font></b></o:p> </p> <p class="MsoNormal"><font face="Arial" size="2"><o:p></font><font face="Arial" size="1">Posted August 17<br> World Science staff<br> </font><br> <b><font face="Arial" size="2">Some animals, in seeming violation of evolutionary logic and every natural instinct, patiently forego sex until and unless they win a place at the top of their group's pecking order. Researchers are learning why this might be.</font></b></p> <p class="MsoNormal"><b><font face="Arial" size="2">Cornell University's P.M. Buxton says clownfish have arranged such a predictable, orderly way of climbing their social ladder that waiting to breed makes sense. Each of the two to six clownfish that typically form a clownfish group, which lives in protective coral reef niches, occupies a separate rung on a hierarchy. Only the top pair breeds, possibly because additional breeders would create crowding or resource problems. </font></b></p> <p class="MsoNormal"><b><font face="Arial" size="2">The rules for who gets which rung are simple: newest members go to the bottom, and nobody rises until and unless someone above them dies or leaves, in which case everyone below moves up one step. </font></b></p> <p class="MsoNormal"><b><font face="Arial" size="2">The system, Buston calculates, gives everyone a reasonable chance of not only eventually breeding, but also of inheriting precious territory. The findings are described in the May issue of the Proceedings of the Royal Society of London.</font></b></p> <p class="MsoNormal"><b><font face="Arial" size="2">A summary of the paper (fairly technical) can be found <a href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=pubmed&dopt=Abstract&list_uids=15252999" target="_top">here</a>.</font></b></p> <p class="MsoNormal"><font face="Arial" size="1">Front image courtesy U.S. Geological Survey</font></p> </body>