Respiratory System, part 1: Crash Course A&P #31
So we all know that breathing is pretty important, right? Today we're going to talk about how it works, starting with the nameless evolutionary ancestor that we inherited this from, and continuing...
==========
Let me introduce you to one of the bravest pioneers in the history of life on planet Earth. An organism that blazed the trail for every single vertebrate that lives on land today -- and many that don’t. It’s one of your most important ancestors. Meet…well, it doesn’t have a name. And we don’t know exactly what it looked like, either. But we do know that about 380 million years ago, this fishy-looking thing with big, fleshy fins achieved one of the animal kingdom’s greatest milestones: breathing air. Sounds simple enough, but believe me it wasn’t. Because, for billions of years before this fishy ancestor came around, basically all of life evolved in water. From the very beginning, the earliest, simplest forms of life -- like bacteria --...
==========
Let me introduce you to one of the bravest pioneers in the history of life on planet Earth. An organism that blazed the trail for every single vertebrate that lives on land today -- and many that don’t. It’s one of your most important ancestors. Meet…well, it doesn’t have a name. And we don’t know exactly what it looked like, either. But we do know that about 380 million years ago, this fishy-looking thing with big, fleshy fins achieved one of the animal kingdom’s greatest milestones: breathing air. Sounds simple enough, but believe me it wasn’t. Because, for billions of years before this fishy ancestor came around, basically all of life evolved in water. From the very beginning, the earliest, simplest forms of life -- like bacteria --...
