Guy Hoelzer  wrote:

> John,
> 
> I have snipped a small piece out of a much longer interchange between you
> and Tim.
> 
> in article c7ph32$1cj$1{at}darwin.ediacara.org, John Wilkins at
> john_SPAM{at}wilkins.id.au wrote on 5/10/04 8:25 PM:
> 
> >> So - if all members of a species are born and live inside the
guts of some
> >> other animal - I would say they *inherited* this environment, and would
> >> thus have no issue about certain environmental factors being
inherited by
> >> a species.  Similarly, sea creatures inherit the ocean environment.
> >> Similarly, thermophiles inherit their hot, sulphurous
environment - etc.
> > 
> > Inheriting an environment is called niche inheritance. It occurs at
> > kin-group levels or at the most inclusive, at the demic level.
> 
> What is the basis for asserting this limitation?  It seems plain to me that
> daughter species most often inherit environments from their parent species.
> In support of my claim I suggest that the parental species of almost every
> fish species on earth lived under water, while the parental species of
> almost every species of passerine bird lived in part in the air.  This
> example probably covers a much larger scale of comparison than you had in
> mind, but it is still a valid comparison for the illustration of
> environment-inheritance at the species level.  In addition, I think the same
> pattern holds at every scale of comparison, although heritability is always
> harder to detect when comparing only very closely related individuals (or
> species).
> 
This is a bone of contention, isn't it?

Take your usual large bodied animal or plant species. The typically
exist over many patchy environments, each of which differs slightly or
greatly from each other. A wide-ranging species will inherit all these
environments unequally from its ancestral species.

Now take a localised species like Gould's snails (or JT Gulick's
snails). They vary across distances of only metres. Microclimates
account for some of this, but also local drift and sexual selection and
the like. So it is not through niche inheritance that they are what they
are. At least in thos ecases.

But niche inheritance is more than just being in the same conditions as
your parental species. It is a matter of inheriting an environment that
has been modified. For example, elephants will generate scrubby savannah
in Africe by knocking down trees, which favour the selection of equally
large progeny (NB, we're talking within species here), while pigmy
elephants on (I think) Madagascar may not have modified the environment
in the same manner or to the same degree.

In any case, it seems to me that species most of the time do not inherit
identical environments as their ancestral species except in very broad
terms (water, air, temperate or tropical, etc) and they are hardly
properties of the species as such. And species also change these too.

-- 
Dr John S. Wilkins, www.wilkins.id.au
"I never meet anyone who is not perplexed what to do with their
 children" --Charles Darwin to Syms Covington, February 22, 1857
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