John Stevens Henslow, British priest, geologist and doctoral advisor to Charles Darwin (born 1796)

John Stevens Henslow was an English Anglican priest, botanist and geologist. He is best remembered as friend and mentor to Charles Darwin.

Charles Robert Darwin was an English naturalist, geologist, and biologist, widely known for his contributions to evolutionary biology. His proposition that all species of life have descended from a common ancestor is now generally accepted and considered a fundamental scientific concept. In a joint presentation with Alfred Russel Wallace, he introduced his scientific theory that this branching pattern of evolution resulted from a process he called natural selection, in which the struggle for existence has a similar effect to the artificial selection involved in selective breeding. Darwin has been described as one of the most influential figures in human history and was honoured by burial in Westminster Abbey.

May 16 is the 136th day of the year in the Gregorian calendar; 229 days remain until the end of the year.