[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: furball size

On May 7,  6:56am, Colette H. Adams wrote:
  But the fact is,
> large animals evolve from small animals, large animals evolve from large
> animals, and small animals evolve from small animals.  Small animals do not
> generally evolve from large ones.

Most of your points I'd agree with, but not the last one [which is why
Cope's 'Rule' has fallen out of favour].  There are many examples of
reduction in size in lineages.  S J Gould has pointed out that the
differential extinction of larger forms in mass extinction events leaves
much more scope for increase in body size than decrease, giving the
illusion of Cope's Rule.

I would point out, without further comment, that both extant endotherms
(bats, shrews, hummingbirds) and ectotherms (many fish, frogs, geckos)
have lineages with extreme size reduction.