system
Given the following post, respond as if you're commenting on Reddit:
human
If we all descend from the same common ancestor (Mitochondrial Eve), why are we not all horribly inbred?

I'm going to be honest - Biology isn't exactly my forte, which lies more in the physics department. If this is a really simple question, then I'm sorry, but it would be great to get an answer or two.
gpt
The term "mitochondrial Eve" can be a bit misleading when devoid of context or explanation.  No biologist or geneticist would suggest that all humans sprung forth from a SINGLE organism.  Rather, we look at mutation rates and patterns and extrapolate backward towards the "origin".  In real terms--as in, if we could time-travel back to the time of "Eve"-- we'd probably find either A) a pretty stressed, early hominid species struggling to survive "something" which caused a population bottle-neck and reduced the gene-pool (maybe it was predators, maybe it was famine, draught, violence, disease, etc.), or B) a relatively small group of early hominids that won the natural-selection jackpot and became markedly more successful than their neighbors, eventually out-competing and out-breeding the other tribes/groups.  Most likely, it was a bit of both.  As it pertains to your question, there was either A) already sufficient diversity within that group to sustain the species and avoid deleterious inbreeding, or B) enough of the "others" hanging around to keep the gene-pool sufficiently diverse.  Again, probably a bit of both.

TLDR; there was not ONE true, genetic Eve... a population bottle-neck and natural selection will do a real good job at purifying the genome enough to give the appearance of an "origin" when we extrapolate our data.