The arid Southwest is ideal for preserving plant and animal remains. It's a living laboratory for scientists. At the Ancient DNA Lab at Northern Arizona University, wildlife geneticist Faith Walker is using tiny pieces of mummified biological material to learn more about life on Earth thousands of years ago.
"DNA has stories," Walker says, "so we can tap into the stories of these ancient species. We can learn about old migration routes. We can learn what species ate in the past, and we can learn about pathogens that are important to humans." Walker adds, "For species that are still in existence, we can then project how climate change will impact them and their distribution."
Walker extracts DNA from plant tissue, teeth, skin and prehistoric artifacts. She examines everything from pack rat middens, to the dung of giant ground sloths found in the Grand Canyon. Ecologist Carol Chambers is using DNA to find out how a 10,000 year old bat compares to modern day bats still using the same caves.
"With each animal we capture," Chambers says, "we're able to take a genetic sample - not invasively - and now with these ancient bat samples we can look at this population across time and space. We have the potential to really say something about this population that no one has been able to do before.
The lab is isolated from other genetic study facilities at NAU so the tiny, rare DNA isn't contaminated. The samples are stored in a special freezer that sends off alarms and text messages to researchers if something goes wrong.
Brain Food is produced by KNAU, Arizona Public Radio.