Comment on How many people would a generation ship need to have for inbreeding to not be an issue?
AbouBenAdhem@lemmy.world 2 months ago
There are actually two issues:
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The most obvious effect of inbreeding is the increase in homozygosity for deleterious mutations, causing more birth defects.
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A subtler effect is the loss of genetic diversity reducing a population’s ability to continue to evolve in response to future selection pressures. This would be especially important when migrating to a new environment with new selection pressures the species has never encountered before.
bluGill@fedia.io 2 months ago
Of course once they arrive and population expands we can expect random mutations to build up over the next 100k years or so. If you can last that long.
porcoesphino@mander.xyz 2 months ago
And presuming a species that built a generation ship doesn’t have the ability to handle these environmental changes (either through “fixing” the environment or the genes). And there are two migrations here. I’m not seeing much targeting the earth to generation ship migration directly here. But, they’d all die in free space so the ship is an environmental “fix” and they may need a genetic “fix” to handle things like long term exposure to lower gravity, or some quirks of centripetal gravity.