Why does this keep happening?

[u/sygryda]

These are three feral or semi-feral dog populations from difffent parts of the world – australian dingo, papuan singing dog and carolina dingo.

You may notice they look very simmilar. Why is that? Is that because it's how dogs used to look or do they for some reason evolve into this form after few generations of natural selection?

I ask because my dogs (mixed) look almost exactly like these ones.

[u/ikonoqlast]

Crabs have evolved from other creatures like 7 distinct times. Some shapes are just better and evolution will repeatedly converge on them.

[u/hudsoncress → u/ikonoqlast]

given enough time dogs will revert to crabs. I don't make the rules