[jmyeet]

This is a kinda silly argument. Interstellar colonies would have the opposite problem: they'd cease to be the same species due to genetic drift.

If you look at the (im)practicalities of interstellar travel, it's going to take centuries. That means a generational ship of some kind. That means having a sufficient population to get there, which really means tens of thousands of people. Plus, the kind of ship that would make that would likely host up to millions. That's just not going to create a genetic bottleneck.

Also, you could even mitigate that by bringing frozen genetic material.

[pianopatrick]

I don't know if a generational ship is absolutely required. There's this assumption that interstellar ships would be full of human astronauts who are alive and awake. But that might not be strictly required. You might be able to have everybody go there frozen. Or have a robot ship that gives birth to the colonists from an artificial womb on arrival.

[qayxc]

> You might be able to have everybody go there frozen.

Common trope in sci-fi, pretty much impossible in practise. Humans aren't capable of surviving being frozen, we lack the genetic machinery for that. Could you breed/engineer hybernation-capable humans? Sure. Otherwise this approach would require to literally being able to kill and then resurrect people at will.

> Or have a robot ship that gives birth to the colonists from an artificial womb on arrival.

I like this idea. It kills two birds with one stone: for one, fertilized eggs and fetuses can be stored safely for a long time.

Secondly - and I think this is something that's underdiscussed - genetic modification will be necessary anyway. The target environment won't be a carbon copy of Earth. Different atmosphere, different gravity, different starlight, different pathogens, etc. If you insist on colonising planets and start terraforming via automated means ahead of time, the resulting ecosphere will still differ from Earth and adjustments will be necessary. A ship carrying unborn settlers would be informed of the specifics of the target world and the ship's biolabs could make genetic alterations accordingly.

[pianopatrick]

As well, fertilized eggs and fetuses take up much less mass and do not require internal atmosphere too much. So you could have a smaller, simpler ship that takes less energy to get there

[bethekidyouwant]

if you have robots that are sufficiently sophisticated that they can raise children you are just sending von Newman probes with extra steps.