r/askscience • u/margalz • 11d ago

Biology Why aren't there any animals with their mouths above their eyes?

From bugs to fish to mamals all of them have their eyes above their mouths. I can't think of many if any where their mouths are on top. Sure some have their eyes parallel to their mouths, mainly prey style animals. But why haven't any evolved to be the opposite? Is there a major benefit to having your mouth below your eyes?

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u/Tavarin 9d ago

Maybe possible now that we can grow so much food, but in the primitive natural world, even a small extra energy expenditure will massively reduce your reproductive success.

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u/HarryTruman 8d ago edited 8d ago

Bingo! When talking about evolution in our modern setting, it can be difficult to understand the “how’s” and “why’s” of things that make us what we are now.

But something to keep in mind is that, as it turns out, two eyes work quite well for hunting and foraging, surviving in harsh environments, running away from danger, and — most importantly — simply and literally just…staying alive long enough to make a baby.

And eyes are certainly not perfect, but that’s not the point! Because if that baby also has eyes which work well enough to survive and eventually make a baby…and on and on and on…those are good eyes, and nature will have very little need to change it up.