Re: Speciation - how do you know?
HARRY R. ERWIN (herwin@mason2.gmu.edu)
2 Oct 1996 14:37:00 GMT
Paul Crowley (Paul@crowleyp.demon.co.uk) wrote:
: In article <52lrce$snj@lyra.csx.cam.ac.uk>
: nmm1@cus.cam.ac.uk "Nick Maclaren" writes:
---mostly trimmed---
: Compare these putative hunters to a pride of lions. They have
: everything, including sprinting speed. Lions do not find life that
: easy. They never adapted to Europe (AFAIK). The prey is too rare
: or too dangerous or too something else. So how could a much less
: effective hunter with a much greater energy requirement make out?
Fossil lions are known from Africa, Europe, Asia, North America (P.
atrox), and South America (P. atrox). Lions are still extant in Asia
(India) and Africa, and were known historically in Europe.
: > Also, remember that a large animal will feed a group of 40 for a
: > week or more - i.e. only 50 kills are needed a year. And such a
: > group can afford a couple of deaths a year, assuming that hunting
: > accidents account for most deaths of adult males.
: In a group of 40, you'd only have 8 or fewer mature males. So
: your group has to be much larger. Even then the rate of death
: or serious injury would seem much too high. Comparing with other
: predators (assuming H.n. was a predator) such as lions, the risk
: of serious injury has to be much lower. H.n.'s lifespan is much
: longer and the replacement of a mature male would have been much
: slower and more costly.
Reduce the casualty rate to one per year, and you're in the right
ballpark.
: Paul.
--
Harry Erwin, Internet: herwin@gmu.edu, Web Page: http://osf1.gmu.edu/~herwin
49 year old PhD student in computational neuroscience ("how bats do it" 8)
and lecturer for CS 211 (data structures and advanced C++)
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