Moon pregnancies and child development

--- In spacesettlers@yahoogroups.com, Douglas May wrote:
> In all
> likelihood, human settlements in space will evolve to become even
> more dependent on technology than we currently are. This is just fine
> as long as you can maintain your technology, but an economic dark age
> or catastrophe could create an evolutionary bottleneck that would
> likely result in differentiation or even speciation: only those
> individuals on the settlement with the genes to breed in zero G
> without technological aid would survive such a dark age.

There will be evolutionary pressures without any economic collapse:
it's far cheaper and simpler to build a zero-gee habitat or spaceship
than one that requires 1-gee gravity. Getting work done in zero-gee
takes less energy than it does in 1-gee gravity (all other things
being equal) There will be products manufactured in zero-g, needing
workers who can be there in zero-g. Playing around in zero-g is more
fun...etc. All of these will mean economic incentives to adapt to
zero-g, to those individuals capable of adapting to it.

What one might expect to see centuries from now are *large*
settlements full of people who still require a full 1-g to live and
reproduce, while on the frontier in outlying areas will be very small
settlements of people who have adapted to zero-g.

> But shorter term, I think a combination of "natural" childbirth and
> golly-gee-whiz technology will allow breeding in lower G environments
> with no problem.

My gut-level feeling is: there's no substitute for good old-fashioned
1-G gravity when it comes to pregnancy and early childhood. In fact,
even the simulated gravity provided by a rotating place might not be
good for raising humans: the coriolis force and constant motion might
play havoc with small children's balance, for example.

> The problem is going to be getting enough "heavy"
> humans out of Earth's gravity well to create a viable gene pool in
> the first place. A colony of 5 or 10 or even 100 astronauts will not
> have enough genetic diversity to find the right genetic combinations
> to thrive in space.

There have been quite small colonies started by quite small groups of
people that nevertheless survived. The Mayflower colony would be one
example. In the remote past, parts of the Earth were colonized by
*very* small numbers of individuals, perhaps only a dozen or so...
those survived also.

I'm no expert, but I think 100 individuals is enough genetic
variation to start a viable colony.