Washington is wild about Abraham Lincoln, who was born 200 years ago today. In the nation’s capital, where the Lincoln Memorial anchors one end of the National Mall, it’s easy to forget that today marks another bicentennial, the 200th anniversary of the birth of Charles Darwin.

Darwin and Lincoln are more similar than you might think.

Both were controversial: Lincoln emancipated the slaves and waged an unpopular civil war to keep the United States united; Darwin’s idea that natural selection is the purposeless mechanism by which animals evolve was criticized as incompatible with religious beliefs.

Both emphasized fundamentals: Lincoln stressed equality, the bedrock of democracy. Darwin stressed evolution by natural selection, the bedrock of biology.

Both were talented writers. Lincoln’s speeches are part of the canon of American history; his second inaugural address is widely acknowledged as extraordinary. (“Both parties deprecated war, but one of them would make war rather than let the nation survive, and the other would accept war rather than let it perish.”) Darwin’s books also have stood the test of time. “On the Origin of Species” and “The Descent of Man” are classics. (“It may be said that natural selection is daily and hourly scrutinizing, throughout the world, every variation, even the slightest; rejecting that which is bad, preserving and adding up all that is good; silently and insensibly working, whenever and wherever opportunity offers, at the improvement of each organic being in relationship to its organic and inorganic conditions of life.”)

Both are featured on currency. Lincoln’s profile is on the United States’ 1 cent coin, Darwin’s visage can be found on a British £2 coin. Lincoln’s coin, although of small value, is ubiquitous. Darwin’s coin is new and commemorative and much more valuable than a penny – not that this is a competition.

Happy Birthday, Charles Darwin!