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Re: Watery evolution of man?
- To: Dinosaur Mailing List <dinosaur@usc.edu>
- Subject: Re: Watery evolution of man?
- From: "T. Michael Keesey" <keesey@gmail.com>
- Date: Thu, 10 Jan 2008 15:24:17 -0800
- In-reply-to: <457242.84773.qm@web54112.mail.re2.yahoo.com>
- References: <20080110221910.E03F9F4009@mail01.chariot.net.au> <457242.84773.qm@web54112.mail.re2.yahoo.com>
- Reply-to: keesey@gmail.com
- Sender: owner-DINOSAUR@usc.edu
This is probably getting a bit OT, but....
On Jan 10, 2008 2:56 PM, Andrew Simpson <deathspresso@yahoo.com> wrote:
>
> I've always been interested in the concept that our
> ancestors spent some major time in the water. The
> theory being that that is why we have "hairless" skin,
> webbed fingers and toes,
Again, the problem here is that "hairlessness" seems to have arisen
quite recently in our ancestry. This would basically require archaic
_Homo sapiens_ to be amphibious.
The AAH is also supposed to explain habitual bipedalism, which goes
back at least to very early stem-humans, and quite possibly further.
(It may be basal to _Hominini_, or even _Hominoidea_, with several
lineages -- orangutans, gorillas, chimpanzees -- developing modes of
quadrupedal locomotion. Gibbons, for example, are habitually bipedal,
and other non-human apes, especially bonobos, are capable of bipedal
locomotion.)
The timing just isn't there, unless everything from _Orrorrin_ to
pre-_sapiens_ _Homo_ is amphibious. All the paleontological evidence
places these stem-humans in grasslands or woodlands. Not that there's
no evidence of coastal dwelling, but it's certainly not the major
environment.
> and mate (most commonly) face to face. Which only water creatures do.
Bonobos also mate face-to-face, and they are certainly not amphibious.
(Incidentally, are there any studies on frequency of human sexual
positions? How certain are we that the "missionary position" is the
most common one?)
> Our noses may play into this as well.
To be fair, the only other primate with a similar nose, the proboscis
monkey, is a proficient swimmer. Of course, their noses are also
sexually dimorphic, so there's some kind of sexual selection at play.
But even so, females still have larger noses than other non-human
primates.
--
T. Michael Keesey
Director of Technology
Exopolis, Inc.
2894 Rowena Avenue Ste. B
Los Angeles, California 90039
http://exopolis.com/
--
http://3lbmonkeybrain.blogspot.com/