From Primates to People

Human evolution was a branching journey:

• We are apes: Humans and chimps share an ancestor from 6-7 million years ago, differing by only about 1.2% of DNA.
• Bipedalism started everything: Walking upright freed the hands for tools and saved energy.
• Built to run: efficient sweat cooling let early humans stay active in the heat — possibly for endurance (‘persistence’) hunting, though that idea is still debated.
• Brains tripled fast: This consumed about 20% of body energy.
• Fire and society fueled growth: Cooking freed calories; social demands rewarded larger brains.