A history of the theory of mass extinction events

I had no idea that the theory of mass extinction events only came to be accepted within my lifetime. From the Washington Post, an interview with New Yorker science writer Elizabeth Kolbert.

Brad Plumer: Let’s start by walking through the history of science here. Back in the 18th century, no one even knew that there wereany extinct species. How did we get from there all the way to realizing that there had been five of these mass extinction events in Earth’s history?

Elizabeth Kolbert: There is an interesting history there. Up until the early 1800s, the concept of extinction didn’t really exist. Even early in the 19th century, you had Thomas Jefferson hoping that when he sent Lewis and Clark to the Northwest, that they would find mastodons roaming around. Mastodon bones had been unearthed — there was a very famous one unearthed in New York and displayed in Philadelphia — and people thought they must still exist somewhere.

But right around that time, a French naturalist named Georges Cuvier came to the realization that look, if these animals were out there, we would have seen them by now. They are not there. And that made sense of a lot of things. There were these bones that were very, very hard to explain. And more and more of them as Europeans colonized the New World, they were getting these bones shipped to them. It made sense of these weird nautical creatures that had been found that no one ever found.

S0 extinction actually predated the concept of evolution by about half a century — people knew that things went extinct, even though they didn’t really understand how species came into being. But there was still some debate. Cuvier thought that when extinctions happened, it must be because the Earth changed quickly and catastrophically. Why else would an animal that was perfectly suited to life on this planet go extinct? His theory became known as “catastrophism.” And Charles Lyell and Charles Darwin came along and said, that’s ridiculous, the Earth changes slowly, we’ve never seen a catastrophe, that’s because they don’t exist.

That paradigm persisted until the 1980s and 1990s. That was when Walter Alvarez and his father Luis Alvarez came up with the theory that an asteroid impact had done in the dinosaurs. And that idea was actually resisted for the same reasons — the dominant view was that the Earth does not change quickly. But then it was proven.

And so now the prevailing view of change on planet Earth, as one paleontologist put it, is that the history of life consists of long periods of boredom interrupted occasionally by panic. It usually changes slowly, but sometimes it changes fast, and when it does, it’s very hard for organisms to keep up.

Read the rest here.

A history of the theory of mass extinction events