Even very smart people can try to shoehorn new information that just doesn't fit into an existing paradigm.For a long time the story that we've been telling ourselves is that humans are just another animal. We evolved from other animals and our place in the universe isn't particularly special. What I'm trying to convey in my book [The Sixth Extinction] is that we are unusual.

Humans will eventually become extinct. People treat that as a radical thing to say. But the fossil record shows us that everything eventually becomes extinct.

It is estimated that one-third of all reef-building corals, a third of all fresh-water mollusks, a third of sharks and rays, a quarter of all mammals, a fifth of all reptiles, and a sixth of all birds are headed toward oblivion. The losses are occurring all over: in the South Pacific and in the North Atlantic, in the Arctic and the Sahel, in lakes and on islands, on mountaintops and in valleys.

Mitochondrial DNA, which is a sort of abridged version of DNA, is passed directly from mother to child, so it's something that can be looked at to trace matrilineal descent.

Even very smart people can try to shoehorn new information that just doesn't fit into an existing paradigm.For a long time the story that we've been telling ourselves is that humans are just another animal. We evolved from other animals and our place in the universe isn't particularly special. What I'm trying to convey in my book [The Sixth Extinction] is that we are unusual.

We can't say that when x happens we get a mass extinction. To the extent we understand mass extinction, one has been caused by glaciation event, one has been caused by a massive climate change, and one has been caused by an asteroid. These events turn out to have no precedent.

Most of us live in parts of the world where we don't expect to see much, and we wouldn't necessarily notice things that are crashing.