This month in history: February anniversaries momentous or merely memorable.(The Descent of Man, United Service Organization and Alan Shepard)

140 YEARS AGO DOING IT NATURALLY

After explaining evolution in On the Origin of Species (1859), Charles Darwin examines its role in human lineage in February 1871 in The Descent of Man. His big ideas--people belong to a single species descended from an ancestor shared with other mammals, and sexual selection, or competition for the opposite sex, can account for variations--are now mainstays of biology.

70 YEARS AGO SHOW STARTER

With war on the horizon, the United Service Organizations forms in New York February 4, 1941, when several national charities band together to raise the morale (and morals) of American troops by supplying recreation, education and …