The German tribes, pre-Islamic Arabs, and ancient Japanese, Chinese, and Indians all practiced infanticide in one form or another.The 1859 publication of Darwin’s The Origins of Species didn’t just get scientists thinking about how finches evolved in the Galapagos but about how human societies evolved more generally.Applying Darwin’s principles of natural selection to human societies, Darwin’s cousin and scientific polymath Sir Francis Galton theorized that human evolution would regress if societies prevented their weakest members from being selected out.In his influential books Hereditary Talent and Character (1885) and then Hereditary Genius (1889), he outlined how eugenics could be applied positively by encouraging the most capable people to reproduce with each other and negatively by discouraging people with what he considered disadvantageous traits from passing on their genes.These theories were embraced by mainstream scientific communities and championed by luminaries like Alexander Graham Bell, John Maynard Keynes, Woodrow Wilson, and Winston Churchill.