[extropy-chat] Bowhead Whales May be the World's Oldest Mammals

[Robert Bradbury]

On 3/28/07, Damien Broderick <thespike at satx.rr.com> wrote:
>
> Some birdies live very much longer than ground critters that
> are metabolically very similar. The usual explanation is that the
> lack of lots of natural aerial predators for these birdies allows
> genetic drift, mutation, etc to extend their longevity, since
> antagonistic pleiotropy is not pushing the value of adaptations that
> are not usually injurious due to natural early mortality from
> predation, intraspecific sex-contest injury, or infection.


Actually this gets a bit tricky.  The real probable cause for longevity in
flight enabled creatures is the ability to select environments that nobody
else is adapted to (think cave dwelling bats for example).   The problem
with predators is that is its a "hazardous" profession.  Lions get stabbed
by dusks, elephants fall on you, etc.  This ends up predators usually prey
on things which are smaller.  But smaller has less inertia and is therefore
faster.  (Do hawks prey on hummingbirds?)  The size vector, particularly if
you can combine it with intelligent  social groups (more watchful eyes for
predators, collective food harvesting activities, etc.) tends to allow one
excellent management of the "predator" problem, but still leaves one
wrestling with the food resource problem (witness bowhead & blue whales,
elephants, whale sharks which are all long lived).

Robert
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