On Evolution

Let’s talk about biodiversity! Made famous by Charles Darwin (even though Alfred Wallace had come to the same conclusions at the same time), the Theory of Evolution explains the diversity of life alive on the planet today.

Darwin focused his studies on finches, little birds like these. He noticed some finches were better suited for eating bugs, or seeds, or whatever. How could differences like these arise, he asked? Photo by Dušan veverkolog on Unsplash

Friendly reminder that in science, a “theory” is an established explanation of how something works that produces testable claims that hold water, time after time. Evolution has been observed, both in the laboratory and in the field. More on that later, once we agree on what evolution is. For context, gravity is also a theory.

The basic idea behind evolution is that living things change over time. A lot of time, generally. Approximately 3.6 billion years ago, the first early cells coalesced, forming the ancestor of everything alive today. We’ve nicknamed this critter LUCA, for Last Universal Common Ancestor. (I say critter, but it was almost certainly a primitive single-celled prokaryote. Still a critter, in my book.)

As this single-celled organism survived, met environmental challenges, and reproduced, certain traits made it more likely that that organism would have lots of babies, making sure the genes for that trait are well-represented in future generations. Other traits were neutral or harmful in the race for babies, so those traits didn’t get passed along.

Some Terminology