Life on Earth has been evolving by natural selection for billions of years, and our species finally realized this less than 200 years ago. We now mark that historic epiphany every February with Evolution Weekend and Darwin Day, both of which honor Charles Darwin.

But not everyone celebrates this discovery. In fact, a large number of people still dispute its legitimacy on religious grounds. Science educator Bill Nye even agreed to debate creationist Ken Ham on the topic this week, 155 years after Darwin published "On the Origin of Species." While most Americans now accept evolution, up to a third still don't.

As Phil Plait of Bad Astronomy points out, such doubt is often based on "a profound misunderstanding of how science works." Nye did a decent job of setting the record straight in this week's debate, which you can watch online if you have 2 hours and 45 minutes to spare. But that's not a very efficient or entertaining way to get a grasp on the basics of evolution. For that, here are two animated videos that offer a much shorter, snappier but still scientifically accurate look at evolution and natural selection.

1. "Evolution vs. Natural Selection" by MinutePhysics

What's the difference between evolution and natural selection? Armed with markers, pencils and an uncanny knack for explaining complex concepts, the folks at MinutePhysics offer a 3-minute primer on the mechanism behind biological evolution:

2. "How Evolution Works" by Kurzgesagt

The video above is a nice overview, but for a more in-depth and elaborately animated explanation, check out this 12-minute breakdown of evolution by information design firm Kurzgesagt. (Note: There are a few seconds of cartoon animals mating at 4:14, and although it's "censored," that scene might not be safe for work.)

Related evolution stories on MNN:

Russell McLendon ( @russmclendon ) writes about humans and other wildlife.