Comment by bee_rider

Evolution is also just optimizing you to live long enough to reproduce and then help your kids get well set up. So, it is fine if your legs start to go in your 40’s. You can help chase down the antelopes ‘till then, then go weave baskets and watch the fire for a decade or so, then die in your 50’s.

Actually, it doesn’t seem like a horrible life, but I think we’re hoping to stick around a little longer.