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Dr. David Gwynn

πŸ‘€ Speaker
1722 total appearances

Appearances Over Time

Podcast Appearances

The Ancients
Ice Age America

certain types of vegetation from an environment. So you've got changing habitats, you've got changing competitive relationships. So lots of different things are happening in the environment. The real tough question is how do you link that to the processes that would have led to the extinction of these animals.

The Ancients
Ice Age America

And the first thing that you need to do is recognize there's not going to be a one-size-fits-all solution to this problem because each animal, each of those several dozen genera of large mammals, which includes actually a number of small animals, which includes, for that matter, trees going extinct at the end of the Pleistocene, turtles going extinct, snakes going extinct.

The Ancients
Ice Age America

And the first thing that you need to do is recognize there's not going to be a one-size-fits-all solution to this problem because each animal, each of those several dozen genera of large mammals, which includes actually a number of small animals, which includes, for that matter, trees going extinct at the end of the Pleistocene, turtles going extinct, snakes going extinct.

The Ancients
Ice Age America

And the first thing that you need to do is recognize there's not going to be a one-size-fits-all solution to this problem because each animal, each of those several dozen genera of large mammals, which includes actually a number of small animals, which includes, for that matter, trees going extinct at the end of the Pleistocene, turtles going extinct, snakes going extinct.

The Ancients
Ice Age America

You've got to figure out on a species by species basis, how are they being impacted by this whole constellation of changes that are taking place at the end of the Pleistocene? So what you have to do is figure out how are all these individual species responding to this constellation of changes that are occurring at the end of the Pleistocene? It has to be done on a species by species basis.

The Ancients
Ice Age America

You've got to figure out on a species by species basis, how are they being impacted by this whole constellation of changes that are taking place at the end of the Pleistocene? So what you have to do is figure out how are all these individual species responding to this constellation of changes that are occurring at the end of the Pleistocene? It has to be done on a species by species basis.

The Ancients
Ice Age America

You've got to figure out on a species by species basis, how are they being impacted by this whole constellation of changes that are taking place at the end of the Pleistocene? So what you have to do is figure out how are all these individual species responding to this constellation of changes that are occurring at the end of the Pleistocene? It has to be done on a species by species basis.

The Ancients
Ice Age America

What are their thresholds? What are their tolerances? What happened in the environment that caused them to spiral into extinction? Here's where ancient DNA comes in. We've not been able to figure this out. You can't learn this from the fossil record when you've got a bone here and a bone there, but you can use ancient DNA to look at changes in genetic diversity.

The Ancients
Ice Age America

What are their thresholds? What are their tolerances? What happened in the environment that caused them to spiral into extinction? Here's where ancient DNA comes in. We've not been able to figure this out. You can't learn this from the fossil record when you've got a bone here and a bone there, but you can use ancient DNA to look at changes in genetic diversity.

The Ancients
Ice Age America

What are their thresholds? What are their tolerances? What happened in the environment that caused them to spiral into extinction? Here's where ancient DNA comes in. We've not been able to figure this out. You can't learn this from the fossil record when you've got a bone here and a bone there, but you can use ancient DNA to look at changes in genetic diversity.

The Ancients
Ice Age America

You can use ancient DNA to measure demographic or population size changes. You can basically, if you get a DNA record through time, and this is something that we're actively working on at the Center for Geogenetics, you can measure, you can actually start to see when species begin to spiral down toward extinction.

The Ancients
Ice Age America

You can use ancient DNA to measure demographic or population size changes. You can basically, if you get a DNA record through time, and this is something that we're actively working on at the Center for Geogenetics, you can measure, you can actually start to see when species begin to spiral down toward extinction.

The Ancients
Ice Age America

You can use ancient DNA to measure demographic or population size changes. You can basically, if you get a DNA record through time, and this is something that we're actively working on at the Center for Geogenetics, you can measure, you can actually start to see when species begin to spiral down toward extinction.

The Ancients
Ice Age America

When they begin to basically lose population, you start to see inbreeding, you start to see changes in reduction in genetic diversity. You can see that the vegetation, and this goes back to something we talked about earlier in the podcast, you can see when the vegetation that had been supporting them for tens of thousands of years is no longer around.

The Ancients
Ice Age America

When they begin to basically lose population, you start to see inbreeding, you start to see changes in reduction in genetic diversity. You can see that the vegetation, and this goes back to something we talked about earlier in the podcast, you can see when the vegetation that had been supporting them for tens of thousands of years is no longer around.

The Ancients
Ice Age America

When they begin to basically lose population, you start to see inbreeding, you start to see changes in reduction in genetic diversity. You can see that the vegetation, and this goes back to something we talked about earlier in the podcast, you can see when the vegetation that had been supporting them for tens of thousands of years is no longer around.

The Ancients
Ice Age America

So with ancient DNA, we are finally going to get past the impasse that we've long had. Blaming extinctions on humans is just a kind of a simple-minded answer, and it doesn't work. It's actually hard work to figure out the link between the climate changes and the extinction of these animals. And that's work that's all in front of us, but work that's being actively done.

The Ancients
Ice Age America

So with ancient DNA, we are finally going to get past the impasse that we've long had. Blaming extinctions on humans is just a kind of a simple-minded answer, and it doesn't work. It's actually hard work to figure out the link between the climate changes and the extinction of these animals. And that's work that's all in front of us, but work that's being actively done.

The Ancients
Ice Age America

So with ancient DNA, we are finally going to get past the impasse that we've long had. Blaming extinctions on humans is just a kind of a simple-minded answer, and it doesn't work. It's actually hard work to figure out the link between the climate changes and the extinction of these animals. And that's work that's all in front of us, but work that's being actively done.

The Ancients
Ice Age America

First Peoples in a New World, Populating Ice Age America. And it's published by Cambridge University Press. It's actually in a second edition, came out in 2021. As for all of the late breaking DNA work, well, stay tuned. Maybe if we have this conversation again in a couple, three years, we'll be able to update your listeners.