Darwinian man, although well behaved At best is a monkey shaved.W. S. Gilbert
The epigraph, taken from the 1909 Gilbert and Sullivan operetta Princess Ida, almost gets the scientific facts right. In the interest of scientific accuracy the lines should read
Darwinian man, though well behaved
Is only an ape who's shaved.
for there are some key genetic differences between apes and monkeys. We and our other ape cousins have lost those elegant monkey tails, developed a different limb structure, and have bigger brains. The ape-monkey genetic changes took place twenty million years ago; five millions years ago more genetic changes produced the hominids. Somewhere around 100,000 years ago our own species, Homo sapiens, a very big-brained species with a limb structure that is fine for walking but terrible for climbing trees, began to spread from our place of origin in Africa, and by somewhat less than 15,000 years ago (the date is still debated) had reached the southern tip of South America, thus populating all the continents except Antarctica.
Genetic change did not stop as humans wandered across the globe. A very large majority of the genes that define humanity are shared by all humans, but there are significant genetic differences between populations. Swedes, Tanzanians, Chinese, and the Quechua Amerindians who live in the Andes differ in their appearance – within the range of human differences – and they differ in other ways as well.