system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why does interspecies breeding not work?

HUGE disclaimer: I just watched a video about how homosapiens and neanderthals likely mated. I have no desire to experiment at home

So like hypothetically, if I, a male human, injected my seed in to a female muskrat, why wouldn't that result in some really messed up muskrat/human hybrid?

Is it because none of the DNA connects? And if so, what's the breaking point? If homosapians and neanderthals can make a human baby. Why can't chimps and gorillas make a chimpilla baby?
gpt
Imagine you’re assembling IKEA furniture, but are taking alternate pages from two sets of instructions.

If both the sets are for the same model table, just from boxes where the table was different colors you’re gonna be able to assemble the table just fine.

If one of the instruction sets is from an older version of the same table you’re *probably* going to be able to assemble it just fine provided they didn’t make any major updates. Eg a while back they made certain pieces of some model lines a little thinner but no other changes. You’ll be able to get away with mixing instructions there.

If one is for a different model table entirely you’re going to fairly quickly have a mess of MDF and fasteners that’s obviously going nowhere.

If one instruction set is for a bed you’re not even going to get started.

Humans and Neanderthals are around Option 2. Chimps and Gorillas are closer to Option 3.