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Re: why larger?



"Dictator-for-life Calvin" (uh huh...) wrote:
>Good question.  Since we've all been talking about small animals 
>evolving into larger ones, does anyone know of any "pygmy" lineages 
>that got big again, or gave rise to larger descendents?
        How could you tell?  Given the lack of intermediates in the fossil
record (corroborated by the prediction that such intermediates should be
rare), we may attempt to reconstruct the path of character state change in a
clade, but we can only approximate it.  Couple this with the confusion
caused by size-linked characters in phylogenetic analysis, which may obscure
the true phylogeny and end up grouping larger animals irrespective of their
decent.
        Some imply that this is unlikely, due to mystical evolutionary
models which they have yet to share.  See all of the "bloody frigging"
"Cope's Rule" posts over the past few months (one is on my web page, btw...).

>I had gotten 
>the (possibly mistaken) impression that pygmyism was kind of an 
>evolutionary cul-de-sac, but I've never heard any explanation.
        I am interested in hearing any explanation of how this could be
myself.  Despite repeated claims of very similar substance, no one has
produced on this list a viable modern model which suggests this, nor
references to such a model.
        I'd still like to know what makes a dwarfing event different from a
speciation event.

        Wagner

+--------------------------------------------------------------------------+
| Jonathan R. Wagner                    "You can clade if you want to,     |
| Department of Geosciences              You can leave your friends behind |
| Texas Tech University                  Because your friends don't clade  |
| Lubbock, TX 79409                               and if they don't clade, |
|       *** wagner@ttu.edu ***           Then they're no friends of mine." |
|           Web Page:  http://faraday.clas.virginia.edu/~jrw6f             |
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