[eli5] Why do insects have lots of legs while larger animals have 4 or 2? Also, why aren’t there any animals (that I know of) with 3 legs?

Question

[eli5] Why do insects have lots of legs while larger animals have 4 or 2? Also, why aren’t there any animals (that I know of) with 3 legs?

In: 381

Answer 1

Evolutionarily larger animals were just born with four legs. No really rhyme or reason behind it other than it worked. Then later depending on the animal it would become two legs for weight variation. And insects and spiders are similar as it all stems from evolution to create the best form for speed and weight carrying. There’s no real reason why we have these number of legs other than it works like there’s no real reason why we have two eyes