system
Given the following post, respond as if you're commenting on Reddit:
human
why are our fingers and toes all different lengths? is there an evolutionary benefit? did earlier humans differ?
gpt
Here’s a mind-blower : most mammals have pretty much all the same bones. It’s just that each one is a different size and shape depending on how it’s used. So humans balance their weight on their feet, while the lesser apes grip with their feet and don’t really ever “balance” for long, while elephants just support a ton of weight. Sometimes one species will fuse two bones that a different species will keep separate, and those will of course be “different”. But they aren’t really that different as far as fetal development goes.

For human evolution: The shape of the foot is a key part of how anthropologists evaluate hominids (like Lucy, famously). 

Taking it one step further, if you compare a 1st trimester human embryo to that of a chicken, it takes an expert to be able to spot any difference on sight. So all living things are remarkably similar. We are all built using the same code, and we all have a common ancestor.

PS: the answers to your first question, then, are GRIP and BALANCE.