From NBC's Mark Murray
Today it's not only Abraham Lincoln's birthday; it's also Charles Darwin's.

And a brand-new Gallup poll tied to Darwin's birthday finds that just 39% of Americans believe in evolution.

As expected, Gallup notes, education plays a big role here: 74% of those with post-graduate degrees believe in evolution. That's compared with only 21% of high school grads (or those with less education) who believe in the theory.

Ditto religion: 55% who don't attend church believe in evolution, versus 24% of weekly churchgoers who believe in it.

And vote here on who you think had a a bigger impact on the world, Lincoln or Darwin?