system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5:why are our fingers different lengths?
gpt
Hands are useful for grasping—hanging onto a tree limb (or hanging onto a ladder), picking berries (or picking up groceries), throwing a clod of dirt (or throwing a baseball). If our fingers were the same length, our hands wouldn't be such flexible tools. When we hold a spherical object like an orange in the palm of our hand, the fingers actually curve around evenly, giving us a firm grip. Tapering fingers (and strong thumbs) allowed early humans to use specially-shaped stones to smash, scrape and cut other objects. (A long pinky finger would be more likely to get caught and squashed itself.) Besides precision grips, our different-length fingers also provide a balanced support for crawling or leaning on our hands.