Why Do Humans Look So Different If We're All the Same Species?

Any two humans share about 99.9% of their DNA. A Chihuahua and a Great Dane are the same species, and they differ far more in body than any two of us. So why do people look so different? In 1972, geneticist Richard Lewontin set out to measure how human diversity is distributed. What he found, and what later studies confirmed, changes how you see every face in a crowd. This video covers: Why surface appearance is a poor guide to genetic difference What the data says about variation within and between populations How a single genetic change can shift skin tone What Cheddar Man’s 10,000-year-old DNA revealed about Europeans How sunlight shaped skin color across the planet Sources and further reading: Lewontin (1972), “The Apportionment of Human Diversity”; Rosenberg et al. (2002), “Genetic Structure of Human Populations,” Science; Lamason et al. (2005), SLC24A5 study; Jablonski & Chaplin on skin color and UV; Kenny et al. (2012), TYRP1 and blond hair in the Solomon Islands; Natural History Museum, London, on Cheddar Man (2018). #HumanEvolution #Genetics #Anthropology #ExistentialScience #HumanDiversity #Science #Evolution #DNA #Documentary #Biology