human evolution and artificial birth

From: zeb haradon (
Date: Tue Jun 27 2000 - 20:18:10 MDT

I was thinking about mid-tech artificial birth (artificial insemination,
artificial wombs) and the way it will effect human evolution. Overall, it
would be positive. I'm pretty sure that with genetic engineering, much of
this may be superceded by direct manipulation, but if genetic engineering
did not exist (and even if it's banned, how long will that last? A few
generations maximum), the technological changes going on in the world of
fertility medicine provide a lot of opportunity for Darwinian evolution.
Here's two I came up with which I thought were interesting, so I'm tossing
them out for discussion:
- Although I am not aware of any particular progress towards this goal, it
makes perfect sense that soon, physical birth will be a thing of the past.
It's dangerous, takes up a lot of time and energy, and I hear that it really
hurts too. If I see a company which is making any progress towards womb-less
birth (via some kind of incubator), I'm going to invest my life savings.
What this means for human evolution is a massive increase in brain size. The
only thing limiting the brain size right now is the narrowness of the birth
canal. Intelligence is a valuable survival trait, and that's why it's
genetically worth the increase in childbirth deaths that humans experience.
It makes perfect Darwinian sense to assume that the death rate for
childbirth (meaning for the woman giving birth) and the size of the brain
are perfectly balanced for maximum benefit/minimum loss. When the
death-during-childbirth factor is removed, there's no limit on the size of
the brain. (OT: here's a great news story related to this topic: ).
- It is possible to seperate X-chromosome bearing sperm from Y-chromosome
bearing sperm in a test tube, thus making it possible to choose the gender
of your child (and I think it is even being practiced somewhat). In many
cultures, female children are not valued as much as men children. The fear
of this technology is based on the fact that it will skew gender populations
as almost everyone chooses to have male children. I would not expect this to
be widespread at least in US culture, although a 60/40 skew is not
unimagineable. In extreme male-supremecist cultures like that being endorsed
in Afghanistan, I would expect a 90/10 skew. The short term, social effects
of this would be bad. I'd expect to see an intensification of attitudes
which treat women as property. Long term and biologically, I'd expect to see
a general increase in any ability which has to do with survival, health,
wealth accumulation, and attracting a mate. The reason for this is that if
only 10% of the population were female, only 20% of the population would
breed. With the roughly 50/50 mix we have now, anyone who is fertile can
have a child. The "most fit" males and females hookup with eachother, as do
the "least fit" males and females. If only 11% of the male population was
breeding, the "least fit" 89% would be weeded out. In this case, whether
"fit" in the Darwinian sense correlates with good or desirable in the moral
sense is debatable.

Zeb Haradon (
My personal webpage:
A movie I'm directing:

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