So posits CNN. Ignoring the sexist wording, my answer is culture. Culture, shared and learned behavior, allowed humans to adapt rapidly to their environment in a way far more efficient and responsive than natural selection. The accumulation of these shared behaviors across generations leads to the other common answers as reported by cnn.com: writing, music, technology, landing on the moon, etc..
Fried broccoli! Actually, maybe Beer!
The archaeology of beer is actually very interesting. Independently in many places around the world, people found that old grains and possibly spit in a jar makes magic. Who knew?
Yea, it is really interesting. Before malting was discovered, saliva was one of the only ways to actually break down the starch to sugars that the wild yeast could then do its thing… of course, as technology progresses, we discover things like malting and Koji 🙂