Re: human evolution and artificial birth

From: Anders Sandberg (
Date: Wed Jun 28 2000 - 14:22:09 MDT

"zeb haradon" <> writes:

> - 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.

I wouldn't at first. While I agree that in vitro wombs make excellent
sense (once the technology is developed far enough) *rationally*,
childbearing is an intensely emotional, (dare I say it?) spiritual and
socioculturally enmeshed affair that radical changes of it will at
best take time. There will likely be some demand for it, and it might
increase over time, but I wouldn't expect a sizeable group of parents
immediately adopting it. It is something new, possibly frightening,
expensive and lacks the emotional buffering caused by a traditional

> 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.

While larger skulls could allow larger brains and brainsize does
correlate a bit with intelligence test results, in vitro wombs
themselves do not enable any intelligence increase. Some genetic
modification or hormone treatment could of course increase brain size,
but it should be noted that the birth canal is not the only limiting
factor. Energy demands can be quite critical in thinking, and I have
begun to form the impression from my readings on glucose enhancements
of cognition that local shortages develop with our current brains. A
larger brain would need more energy and oxygen, and this in turn has
to be supplied by the cardiovascular system - and here scaling laws
might complicate things a lot. Not to mention the musculoskeletal
system of the neck. Just increasing brain size is not going to cut

One advantage which may play a significant role is health. Most likely
many of the genes found correlating with intelligence really code for
good health or resistance against childhood diseases that slow or
impair cognitive development slightly. If in vitro wombs could provide
an environment where infections, birth traumas and later diseases
could be prevented (in utero vaccination?), then that would already
lead to a measurable intelligence increase IMHO.

> - 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.

You assume several things here that I find doubtful.

First is that a gender inbalance would reinforce the misogynic
tendencies, when it could just as well lead to an increased value of

Second, you assume that fit individuals in a population where few can
reproduce will hook up with each other. First, fitness in an
evolutionary sense (many grandchildren) have little to do with
survival, health and wealth accumulation today - it would be the
people who reproduced more that would be the winners, and as a general
rule the higher the level of education and social status in modern
societies the fewer kids on average. Second, you assume that in this
scenario the good properties would be significantly inhereited
(genetically or memetically) - this may hold only for some
properties. Third, it assumes that only the best mate with the best,
which is also not necessarily true.

Anders Sandberg                                      Towards Ascension!                  
GCS/M/S/O d++ -p+ c++++ !l u+ e++ m++ s+/+ n--- h+/* f+ g+ w++ t+ r+ !y

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