Eli5: How much of a species’ sequenced genome is stable enough to represent a species, as opposed to finer stuff that will keep changing really fast as they breed?

Question

I know this would vary a lot between species, so for example, what’s this like in the human genome?

In: Biology

Answer 1

I’m not an expert on this, but just want to point out that a genome doesn’t need to be constant to identify a species. If a gene has several options that are typical for humans then having any of these represents a human, even though not all humans have all of them.