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Re: exception to body size/reproductive capacity etc. argument

In a message dated 98-05-12 10:47:39 EDT, PATG@vax2.concordia.ca writes:

<< The relationship between small body size and fast turnover of
 generations doesn't always hold.  Bats are the second-largest group of
 mammals (in terms of species), and most are very small, but they
 reproduce slowly (very few species normally produce more than 2 young
 per year, many produce only one).  There is at least one record of a
 microbat in North America reaching the age of 30 years: not something
 one would expect in, say, a rodent of the same size.  So yes, small
 creatures often live faster, but not always.  Also remember parrots:
 they aren't all that big, but some live longer than humans.  So I
 don't think it's safe to try to generalize on the subject. >>

Fast generational turnover occurs in many, though--as usual in biological
generalizations--not >all< animals of small body size. Other factors
contributing to increased diversity of small animals include having small
territories and having lots of different kinds of predators to provide
selection pressure, among other things. There's nothing wrong with
generalizations as long as one remembers that they're not hard-and-fast rules.
Very little in biology is graven in stone.