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Re: Built Like a Race Horse, Slow as an Elephant?
On 17/01/2007, at 2:25 PM, Sim Koning wrote:
Whether or not herd animals are "competing" with each other or
are hunted individually, the arms race must be intraspecies.
I don't mean to nitpick, bur don’t you mean interspecies, because
intra means within one, not between two.
Good catch. Thinko...
But anyway I completely understand everything you said, I was
thinking about that on my way home and this clears some things up
for me. In retrospect I realize I didn't think my post through
before I typed it. But anyway, to be fair, An arms race, or any
race for that matter, is a type of competition, so I think it would
make more sense to say, interspecific and intraspecific
competition. Dann would be just as correct in saying there is an
“arms race” between two members of the same species as he would be
saying there is an "arms race" between predator and prey. "Arms
race" is just a metaphor for competition anyway, since I don’t
exactly think cats and antelopes are actually building nuclear
weapons and fighter jets. Again I know I'm nitpicking, this is just
semantics and I understand your point.
I'm a philosopher. Picking nits is professional courtesy and
semantics is the fleas. The metaphor of "arms race" implies offence
and defence on the part of the competitors. While it may be true that
a variant within a species is competing, this is like a race rather
than a boxing match. Predators and prey attack and defend -
intraspecific competitors merely try to outrace. As I recall the
origination of the metaphor, in Dawkins and Krebs 1979 article, they
did allow for intraspecific arms races, but not for environmental
selection, but for, say gender conflict, mate competition, or sex
ratios. Looking it up now, I find this comment:
"Bit it [intraspecific arms race] is an arms race between two
branches of the same conditional strategy, not an arms race between
two independent lineages with separate gene pools." [p500]
Dawkins, R, and JR Krebs. "Arms Races between and within Species."
Proceedings of the Royal Society of London, Series B 205 (1979): 489–
--- Dann Pigdon <firstname.lastname@example.org> wrote:
Actually, it was almost certainly a
pronghorn/pronghorn arms race. There would always have been far
more pronghorns than
cheetahs, so cheetah predation on a population of slow coaches would
still not have been enough to threaten their long-term survival.
I don’t exactly agree with this. If cheetahs could easily catch
all members of their prey species, then less cheetahs would starve,
which would increase the number of cheetahs, which in turn would
decrease the number of prey. The same would be true in reverse, if
the prey was too fast for any cheetah to catch, then the cheetahs
would starve and the prey species would overpopulate. This is where
the “arms race” comes in, as Wilkins explained. Equilibrium is
maintained between the two species. Now there are cases where a new
predator species is introduced into an ecosystem that is far faster
or deadlier than what a prey species is adapted to cope with, if
the prey species can’t adapt fast enough to cope, it will go
extinct. So in other words, there are cases where the so called
"arms race" is lost.
Invasive species upset the "balance of power" as it were, whether
predator or niche competitor for prey species. So you get a period of
bellum omnia contra omnes for a while until a new balance is reached,
or the ecosystem collapses and a new one is constructed.
John S. Wilkins, Postdoctoral Research Fellow, Biohumanities Project
University of Queensland - Blog: scienceblogs.com/evolvingthoughts
"Darwin's theory has no more to do with philosophy than any other
hypothesis in natural science." Tractatus 4.1122