Bryan Derksen wrote:

On Wed, 30 Jul 2003 00:22:24 -0400, "Tony Sivori"
<TonySivori@yahoo.com> wrote:

Mike Williams wrote:

They don't need to transport significant numbers at any one time between
the stars.

Why not? Do you think the Mayflower brought two Europeans to America, and
then no more? It didn't happen that way.

The Americas were already inhabited when Mayflower made its trip. The
native Americans were all descended from a few small bands that made
the trip over the Berings land bridge.

Which proves my point. It takes a lot more than a single breeding couple.

All you need to populate a planet is a few dozen individuals. If

Which reminds me of a fantasy of mine, but I suppose that is off topic here.
=-)

you've got sperm banks, you don't even have to worry too much about
tailoring their diversity. If you've got artificial wombs, you don't
need to send _anyone_ to start a colony.

And who would raise these children, teach them how to survive, to get along,
to maintain a recognizable form of your culture, and the ways of high
technology? Robot nannies? If you have machines that good, just send them
instead.

A couple arrive and start breeding. After 50 years there's 4 aliens on
each new planet. After 100 years there's 8. After 500 years there's
1024.

You mean there are a few dying inbred drooling idiots.

Inbreeding only causes problems when the starting population has
deleterious recessive genes in it. If you carefully select your
starting population to be free of defects, then the children will be
fine.

I suspect there are no such individuals. And if there were, due to normal
background radiation (never mind the high levels they would absorb on the
trip) they would not stay that way. One stray x-ray and your super clean
gene superman (or superwoman) is just another flawed slob like the rest of
us.

Interstellar is a snap, on these timescales.

Then why aren't they here?

-- 
Tony Sivori