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off_the_cuff_mandate t1_j513a05 wrote

Reply to comment by Slashy1Slashy1 in Given that reproduction is difficult or impossible when both animals have different numbers of chromosomes, how did so many species evolve to have so many different numbers of them? by MercurioLeCher

If the 44 chromosome people survive though, it would likely be without procreating with 46 chromosome people, which would cause them to gradually adapt differently from the 46 chromosome people and eventually become a separate species.

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Slashy1Slashy1 t1_j51f42i wrote

But that requires a substantial population of 44 chromosome people to already exist, at least enough to avoid extreme inbreeding depression.

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harbourwall t1_j52kumd wrote

Inbreeding becomes less dangerous the more common it is, and people in early tribal groups were a lot more closely related than today. Genetic differences between groups increases and all it takes is a bottleneck event to make the tribe of 44s the new standard number of chromosomes. Speciation through increased diversity between many groups of genetically similar individual, followed by selective or random culling of many of those groups.

That's a viable explanation of how we ended up with 46 instead of the 48 the other great apes have.

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