Lay your arm on a flat surface and push your thumb and pinky together. If you don’t see a raised band across your wrist, you are a product of evolution. If you do, you’ve got a useless extra muscle in your arm that is slowly being erased from our genetic code. Source
I just did some research on this and apparently this muscle actually helps you hold a spear (something we as a majority haven’t needed to do much of in recent times, thus it is a mutation that is neither harmful nor helpful to lack this muscle)
But I’ll see you all in the post-apocalyptic world with my genetic advantage to hold and throw spears~
Looks like you’re going to have to do all the spear throwing for me.