On this day in 1974, Lucy — or as her friends know her, AL 288-1 — was discovered. She is our best representative of Australopithecus afarensis, a hominid that lived between three and four million years ago. Her fossilized skeleton is thought to date back to about 3.2 million years ago. What is most interesting about her is she seems to have walked on two legs. At the same time, she had a small skull, like that of non-hominid apes. Thus, we believe that humans walked upright before we developed our ridiculously large brains.
I find this kind of stuff fascinating. We humans are so focused on our brains, but they really are part of a larger evolutionary picture. If not, why don’t all animals just get bigger and bigger brains? Being smarter is not necessarily an advantage. We can see that in our own world. There’s the question people like me hate, “If you’re so smart, why aren’t you rich?!” I also relate it to VHS and Betamax. The latter actually had a better quality, but the former was good enough — along with some features that made it more useful. That’s how I think of rich people who started poor: generally smart enough with the right skills for making money — rarely brilliant.
So why bipedalism and then increased brain size? It appears to be because freeing up the hands led to building of tools. And in that, being smarter was a major advantage. So evolution selected for bigger brains only after our ancestors started walking on two legs. As I said: fascinating.