Re: Human childbirth

On Tue, 03 Jul 2007 02:34:06 -0700,
Vend <vend82@xxxxxxxxxxx> wrote:
On 3 Lug, 11:11, Timberwoof <timberwoof.s...@xxxxxxxxxxxxxxxxxxxxx>
wrote:
In article <1183451063.980847.169...@xxxxxxxxxxxxxxxxxxxxxxxxxxxx>,
Jason Carlson <jcarlso...@xxxxxxxxx> wrote:

I would like to hear everyone's thoughts on human childbirth from an
evolutionary standpoint. It seems to be a rather more difficult and
risky process (especially without readily available medical care) than
other animal births. This to me would seem to be an evolutionary
disadvantage, where as an easier birth would naturally come with a
greater chance of mother and infant survival and thus be
evolutionarily advantageous. So I'm curious as to why it turned out
that Humans have one of the most difficult child birthing processes in
the animal kingdom.

Because our brains are so big and have to go through our mother's hips.
There's no easy way for evolutionary processes to redesign the
topological relationships between internal organs; the best that can
happen is that women's hips are barely wide enough and babies' heads are
squishy enough that enough of the time, things work out and babies
survive.

Why do you think that a re-arrangement of the birth canal would have
been too difficult?
The human skeleton is similar but slightly different from the skeleton
of non-human apes like gorillas and chimps.
If such changes could have evolved from a common ancestor in a
relatively short time, I don't see a re-arrangement of women hips
couldn't have been possible.
Large hips in women are even sexy, thus sexual selection would have
also pushed for enlargement.

Anyhow, I heard that most problems during human birth don't come from
the head but from the shoulders.

Evolution doesn't create perfect systems. The pressure for full bipedalism
was probably far higher than for the decrease in mortality that a rearrangement
of the pelvic area would have required. Let us also consider here that it
wouldn't just mean a reorganization of the female pelvic structure, but of
the *human* pelvic structure.

--
Aaron Clausen
mightymartianca@xxxxxxxxx

.

Relevant Pages

  • Re: Earths Carrying Capacity
    ... > contraception don't work. ... > no effective means of birth control. ... I expect human evolution to now select for birth rates that depend less ... on *accidents* and depend more on planned pregnancies, ...
    (sci.space.policy)
  • Re: Earths Carrying Capacity
    ... >> contraception don't work. ... >> no effective means of birth control. ... > I expect human evolution to now select for birth rates that depend less ... > pregnant whenever possible. ...
    (sci.space.policy)
  • Re: best beginner experience
    ... of millions of years of evolution. ... The best time of our bodies ... is from birth until we have our children. ... That rules cremation out, huh? ...
    (rec.motorcycles)
  • Re: best beginner experience
    ... of millions of years of evolution. ... The best time of our bodies ... is from birth until we have our children. ... Turby the Turbosurfer ...
    (rec.motorcycles)
  • Re: Human childbirth
    ... other animal births. ... Because our brains are so big and have to go through our mother's hips. ... Why do you think that a re-arrangement of the birth canal would have ... I don't see a re-arrangement of women hips ...
    (talk.origins)
Loading