Dan Flores

As Darwin's ally in the breakthrough to understanding natural selection and evolution, Alfred Russell Wallace wrote, "'In fact, we present-day Americans live in a zoological impoverished world from which all the hugest and fiercest and strangest forms have recently disappeared.'" Wallace was using recently in a big history sense.

All those hugest, fiercest, and strangest animals vanished from America between about 13,000 and 9,000 years ago. In fact, we lost 30 genera and 40 species, all of them our very largest creatures. Right down to our present moment, these ancient losses make up the most dramatic extinction event since humans have been in North America.

All those hugest, fiercest, and strangest animals vanished from America between about 13,000 and 9,000 years ago. In fact, we lost 30 genera and 40 species, all of them our very largest creatures. Right down to our present moment, these ancient losses make up the most dramatic extinction event since humans have been in North America.

All those hugest, fiercest, and strangest animals vanished from America between about 13,000 and 9,000 years ago. In fact, we lost 30 genera and 40 species, all of them our very largest creatures. Right down to our present moment, these ancient losses make up the most dramatic extinction event since humans have been in North America.

But science has never grouped the so-called Pleistocene extinctions with the five great planetary extinctions of Earth history. It's different from all of those, which were global, extinguished life on both land and in the oceans, and showed no size bias in the creatures they marked for disappearance. The Pleistocene losses didn't happen in oceans, in Africa, or in Southern Asia.

But science has never grouped the so-called Pleistocene extinctions with the five great planetary extinctions of Earth history. It's different from all of those, which were global, extinguished life on both land and in the oceans, and showed no size bias in the creatures they marked for disappearance. The Pleistocene losses didn't happen in oceans, in Africa, or in Southern Asia.

But science has never grouped the so-called Pleistocene extinctions with the five great planetary extinctions of Earth history. It's different from all of those, which were global, extinguished life on both land and in the oceans, and showed no size bias in the creatures they marked for disappearance. The Pleistocene losses didn't happen in oceans, in Africa, or in Southern Asia.

They devastated life on Earth only in Eurasia, North America, South America, and Australia. Something very odd seemed to be unfolding in specific parts of the planet during the Late Pleistocene. But there is a common thread. Those were all places where human predators out of Africa, seeking out large animals to hunt, were arriving for the first time.

They devastated life on Earth only in Eurasia, North America, South America, and Australia. Something very odd seemed to be unfolding in specific parts of the planet during the Late Pleistocene. But there is a common thread. Those were all places where human predators out of Africa, seeking out large animals to hunt, were arriving for the first time.

They devastated life on Earth only in Eurasia, North America, South America, and Australia. Something very odd seemed to be unfolding in specific parts of the planet during the Late Pleistocene. But there is a common thread. Those were all places where human predators out of Africa, seeking out large animals to hunt, were arriving for the first time.

The Pleistocene Extinctions, in other words, looked very much like the first act of the Anthropocene, the beginnings of what we now call the Sixth Extinction. This has been a prelude to introducing you to a scientist who was able to imagine how this might have happened. Paul Martin, who passed away in 2010, was one of the country's late 20th century intellectual giants.

The Pleistocene Extinctions, in other words, looked very much like the first act of the Anthropocene, the beginnings of what we now call the Sixth Extinction. This has been a prelude to introducing you to a scientist who was able to imagine how this might have happened. Paul Martin, who passed away in 2010, was one of the country's late 20th century intellectual giants.

The Pleistocene Extinctions, in other words, looked very much like the first act of the Anthropocene, the beginnings of what we now call the Sixth Extinction. This has been a prelude to introducing you to a scientist who was able to imagine how this might have happened. Paul Martin, who passed away in 2010, was one of the country's late 20th century intellectual giants.

He was also lucky enough to have a brand new tool to play with, radiocarbon dating, invented in 1946 by Willard Libby, who won the Nobel Prize for it. That new tool almost overnight allowed an understanding of something very crucial about the Pleistocene extinctions— When did the various animals disappear exactly, and how did the arrival of humans in America line up with those dates?

He was also lucky enough to have a brand new tool to play with, radiocarbon dating, invented in 1946 by Willard Libby, who won the Nobel Prize for it. That new tool almost overnight allowed an understanding of something very crucial about the Pleistocene extinctions— When did the various animals disappear exactly, and how did the arrival of humans in America line up with those dates?

He was also lucky enough to have a brand new tool to play with, radiocarbon dating, invented in 1946 by Willard Libby, who won the Nobel Prize for it. That new tool almost overnight allowed an understanding of something very crucial about the Pleistocene extinctions— When did the various animals disappear exactly, and how did the arrival of humans in America line up with those dates?

I got to meet Martin at a point in his career when he seemed to bear a resemblance to a target at a shooting range. At a time when politics and many university departments embraced the idea of ancient peoples as ecological examples for the modern world, there were those who saw Martin's argument that early humans were responsible for extinctions as politically incorrect.

I got to meet Martin at a point in his career when he seemed to bear a resemblance to a target at a shooting range. At a time when politics and many university departments embraced the idea of ancient peoples as ecological examples for the modern world, there were those who saw Martin's argument that early humans were responsible for extinctions as politically incorrect.

I got to meet Martin at a point in his career when he seemed to bear a resemblance to a target at a shooting range. At a time when politics and many university departments embraced the idea of ancient peoples as ecological examples for the modern world, there were those who saw Martin's argument that early humans were responsible for extinctions as politically incorrect.

The popular Native American writer, Vine Deloria Jr., was vitriolic in his condemnation of Martin, which I could tell mortified and baffled the paleobiologist. Between 18,000 and 12,000 years ago, the Saulutrian culture had similarly wiped out Europe's remaining Pleistocene creatures. Clovis and Folsom were not Indian stories, Martin insisted. They were big history human stories.