I thought this answer on Quora was interesting - although I know it won't convince those super-smart folks on this forum that know better...


You want proof of evolution? In human beings?

Here's a simple experiment you can do right now, that is absolute proof positive of evolution.
All you'll need is a few people, preferably people who have arms.

1. Have each of you extend your arm(s) palm side up on the table.
2. Raise your hand slightly at the wrist, and touch your thumb with your pinky.
3. You will see either a raised tendon coming from the middle of your hand at the wrist several inches, or
4. You won't.
What you are seeing (or not seeing) is the palmaris longus muscle, a muscle visible as a small tendon between the flexor carpi radialis and the flexor carpi ulnaris, although it is not always present. It is absent in about 14 percent of the population; however, this number varies greatly in African, Asian, and Native American populations.

So what is this muscle for, and why do about 14% of us not have one?
We inherited the muscle through common descent, and numerous animals that we share a common ancestor with (such as the orangutan) still actively employ the muscle.
Close primate relatives (such as the chimpanzee and gorilla) also do not actively employ the muscle, and hence they also demonstrate the same variability.
The common descent principle suggests that at some stage our ancestor employed the muscle actively. The primate branch then began to evolve the thumb apparatus (and particularly the thenar muscle group) and consequently the palmaris longus became vestigial.
As there is no apparent pressure (positive or negative) concerning the muscle, evolution has largely left it alone.
Its persistence might possibly be due to the fact that the necessary changes to the gene(s) involved in losing the muscle may have other consequences, but this is only speculation.

So, proof positive of evolution right there on your own body, easily seen.
Also proof positive that we share a common ancestor with chimps, gorillas, bonobos, and orangutans.


Amazing how extreme religious folk hate that last sentence