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Re: Non-serpentine lacertids (was RE:WHAT'S GOING ON?)

The fact that long legless lepidosaurs have
evolved several times [much to the distress of all those anti-convergance
people out there], has nothing to do with that.

eric l.

What "anti-convergence people"? I have never met a biologist who didn't accept that convergence happens. The question is the degree of convergence - for example, none of the legless lepidosaurs that are not snakes is identical to a snake (unless you are proposing that snakes themselves are polyphyletic) - it is always possible (and often relatively easy) to distinguish a snake from an anguid, a pygopodid, a legless scincid, or an amphisbaenean (for example).

Those who criticize Feduccia et al for his reliance on convergence as a catch-all explanation for any similarity whatever between birds and maniraptorian dinosaurs are not denying convergence - merely stating (a) that there are so many similarities between the two (with hardly any major differences that are not new to birds) that convergence seems less likely than common descent as an explanation for them and (b) convergence, which requires similar lifestyles to at least some degree, may be a poor explanation for similarities among creatures that may well have faced quite different sets of selective pressures.

Ronald I. Orenstein Phone: (905) 820-7886
International Wildlife Coalition Fax/Modem: (905) 569-0116
1825 Shady Creek Court
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