re: evolution aquatic ape theory - no big predators in the

J de Lyser (gd33463@glo.be)
Mon, 20 Jan 1997 22:31:44 +0100


"E. Shaun Russell" <e_shaun@uniserve.com> wrote:

> Some recents posts by J. de Lyser sparked some ideas into my head.
>First of all, it seems that the variety of predators of pre-humans was less
>than it is now.

Far less, i looked up the data on the hyenids (civet/hyena/catlike
ancestors) in the mid to late myocene, and it not only shows that they were
FOX sized, but that they very probably didn't hunt in packs !!! (as they
were still more civet like than Hyeanid) In fact the only really big
predators around 4 mln years ago, except some smaller versions of what was
to become the sabertooths (america only) were all Aquatic ! The dog-bear
species were small, and inhabited only the arctic regions.

This leaves Acinonyx (a small dumb, solitary hunting cheetah) as the only
real possible threath to LATE Afarensis.

Furtermore the civet like ancestors of the cats in the miocene were all
small. Note that mamal records from the miocene to modern day are good to
excellent !

>I assume that the predators had relatively lesser
>intelligence than the pre-human. John Clark pointed out that the
>pre-human's defensive capabilities were pretty pathetic...though it depends
>on what types of predators the pre-human was up against. If there were
>smilodons about, perhaps the pre-human could jump into a tree...pending that
>the smilodon wouldn't follow. But since I'm not sure about the type of
>predators around that era, I'll go on to the crux of my post.

smilodon only lived in america, acinonyx was a cheetah like species that
only fully developed 2 million years after lucy and was nowhere near as
bright as modern day cheetah (smilodon was plain stupid compared to modern
cats) Acinonyx was therefore matched against a species of Afarensis 2/3rds
of the way from Lucys kind to becoming homo habilis (using tools).

> Consider this scenario. The pre-human was quite easy prey for many
>predatory carnivores (whatever types they may have been).

There were none ! your scenario is best revised this way:

Afarensis therefore, had probably no real predator, as acinonyx influence is
at best doubtfull. Maybe the only real competition of importance to
Afarensis (and pre-homonids in general) were ...other Afarensis /homonids!,
This might explain the much faster evolution (intelligence increase, body
size etc) of homonids compared to most other species.

J. de Lyser
Brussels.