The 50/500 Rule

So, the 50/500 rule.

In the event of some giant catastrophe that wipes out the vast majority of humanity, 50 people is the minimum number of people needed to breed without inbreeding.

While 500 is the number needed to avoid genetic drift, the loss of potentially key genetic traits.

The numbers just sounded good, and in reality, it's more like 5000 we need. But we have like 10,000 left on Earth now, so we're good, right?

Except only 50% are fertile, and there's a minimum of 500 miles between everyone, and fuel deterioration is less than 50 days also.