AILSA CHANG, HOST:
Now we take you to the top of the world, to the northern coast of Alaska where a cliff is crumbling and exposing an ancient hunting site.
MICHAELEEN DOUCLEFF, BYLINE: Oh, there's another head back there.
ZAC PETERSON: Yeah. We got a head right here, a head right there, main body right here.
CHANG: Across the Arctic, these prehistoric settlements are being unearthed. And the reason why is climate change. As NPR's Michaeleen Doucleff reports, scientists are worried about something that could be lurking inside these settlements - zombie pathogens.
(SOUNDBITE OF WAVES CRASHING)
DOUCLEFF: Up on top of an ocean bluff, a team of archaeologists is trying to pull off an emergency excavation.
DOMINIC TULLO: Coming out of here, we have ribs and vertebrae and other long bones.
DOUCLEFF: That's Dominic Tullo, a student helping to dig out a hunting cabin. He's found a stash of animal bones.
UNIDENTIFIED WOMAN: Say that one more time.
DOUCLEFF: At the other end of the house, Glenys Ong shows me where someone was storing fresh kills.
GLENYS ONG: And so this is - this looks like skin right here.
DOUCLEFF: Right at my feet are two mummified seals, and these seals are incredibly well-preserved. You could see their skin, their whiskers.
ONG: And this - oh, it's a little paw.
DOUCLEFF: Oh, it is a little paw.
Everywhere they dig, there's another surprise.
ANNE JENSEN: Holy Moses, this is ridiculous.
DOUCLEFF: That's Anne Jensen, the archaeologist leading the team. They're at a coastal site near Utqiagvik, the town once known as Barrow. They're rushing to save a piece of history before it falls into the ocean. The cliff where the cabin is buried is thawing and breaking apart because of climate change.
PETERSON: It's that a bird?
JENSEN: It's just bird after bird after birds stacked up in there - skin there - ay-ay-ay (ph). Oh, yeah - yeah, there is - oh, my goodness.
PETERSON: It's the whole leg.
PETERSON: Oh, boy...
DOUCLEFF: Things are getting super stinky. The birds are thawing and rotting.
ONG: Oh, that's ripe.
DOUCLEFF: One student's hands are covered in black, decaying bird flesh.
JENSEN: Oh, no, oh, (laughter) her hands - oh, my gosh, oh...
DOUCLEFF: Now Jensen starts worrying about something we can't see.
JENSEN: Avian flu...
COLINE LEMAITRE: The norovirus...
JENSEN: Oh, norovirus, yes.
DOUCLEFF: The team realizes there could be bird flu hidden in these carcasses. You see, all across the Arctic, climate change is causing the ground to warm, soften like butter. And there are a lot of things buried in this ground - not just animals but also their diseases.
JENSEN: Take a break. Take a break, Coline. You're going to drive yourself - go nuts. Seriously, you need a break (laughter).
DOUCLEFF: Colin Lemaitre (ph) is a student. She puts on gloves.
JENSEN: Yeah, you should probably do that rather than go barehanded 'cause, I mean, there's a lot of gunk in here that...
DOUCLEFF: At this point in the excavation, something even creepier happens. A human molar appears.
PETERSON: Wait. It's really a human tooth.
DOUCLEFF: Now, the site we're at isn't a burial ground. There shouldn't be bodies right here. But the tooth does make them pause because it reminds them that there aren't just animal diseases buried in the Arctic but also possibly human diseases. There are tens of thousands of bodies hidden in the Arctic permafrost. Jensen knows this better than anyone.
JENSEN: I've done a lot of burials, yeah. I've probably dug as many burials as anybody.
DOUCLEFF: Some of the people buried up here - they died of smallpox, others from the 1918 flu.
Have you ever seen human remains, like, as well-preserved as this seal?
JENSEN: Oh, yeah.
JENSEN: Yeah, yeah. Well, the little frozen girl from Utqiagvik, (unintelligible) - yeah, she was actually much better preserved than the seal.
DOUCLEFF: The little girl was just 6 years old. She was carefully wrapped in a duck skin parka with a fur-trimmed hood. She had this little sled with her. She died about 800 years ago.
JENSEN: Water had seeped in around her burial I think, and she was - so she was basically encased in ice. We are able to take her out in a block of ice.
DOUCLEFF: Her body was so well preserved that Jensen shipped her to Anchorage so doctors could do a full autopsy. One of those doctors was Michael Zimmerman, a paleobiologist at the University of Pennsylvania.
MICHAEL ZIMMERMAN: I've done a number of studies on frozen bodies in Alaska. And when you open them up, the organs are all there, and they're easily identified. It's not at all like Egyptian mummies where everything is shrunken and dried up.
DOUCLEFF: So it's easy to see what a person died of. For the little frozen girl, it was starvation. But Zimmerman has seen infections in bodies excavated from permafrost. In one case, a mummy from the Aleutian Islands looked like it had died of pneumonia. And when he looked for the bacteria inside the body, there they were frozen in time.
ZIMMERMAN: We can see them microscopically in the lungs.
DOUCLEFF: There's this fear out there that once human bodies are exposed by melting permafrost, the pathogens in them could come back to life like zombie pathogens. It's not unheard of. Anthrax can do it. It happened just a few years ago in Russia. A massive reindeer burial ground thawed, and the anthrax that killed the reindeer woke up and started an outbreak. Were these pneumonia bacteria still alive? Zimmerman tested it. He took a smidge of tissue from the lungs, warmed it up, fed it and tried to revive it.
ZIMMERMAN: Nothing grew.
DOUCLEFF: Not one single cell.
ZIMMERMAN: No. (Laughter) I was happy (laughter) 'cause I didn't have to worry about catching anything.
DOUCLEFF: Zimmerman says he wasn't surprised the bacteria were dead. Anthrax is a special case. In general, bacteria that make people sick can't survive a deep freeze.
ZIMMERMAN: We're dealing with organisms that are hundreds of years old. At least in the stuff I worked on, they're frozen for hundreds of years, and I really don't think they're ready to come back to life.
DOUCLEFF: I ask him if the same is true for viruses.
ZIMMERMAN: I think it's extremely unlikely. We've never been able to culture any living organisms out of these bodies.
DOUCLEFF: In 1951, a pathologist from San Francisco, Johan Hultin, decided to test this out. He went up to a tiny town near Nome, Ala., and dug up the bodies of five people who had died of the 1918 flu, a virus that killed at least 50 million people. Hultin told NPR in 2004 that he cut out tiny pieces of the people's lungs and tried to grow the virus in the lab.
(SOUNDBITE OF ARCHIVED BROADCAST)
JOHAN HULTIN: I hoped that I would be able to isolate a living virus, and I couldn't. The virus was dead. And in retrospect, of course maybe that was a good thing.
DOUCLEFF: Or a good thing - but here's the crazy part. Hultin tried to capture the virus twice. He went back to Alaska when he was 72. And Russian scientists like Hultin have intentionally tried to revive smallpox from bodies in their permafrost. They recovered pieces of the virus but couldn't get that to grow either. So maybe when it comes to zombie diseases, it's not melting permafrost we need to worry about but what scientists are doing in the lab. Michaeleen Doucleff, NPR News.
NPR transcripts are created on a rush deadline by Verb8tm, Inc., an NPR contractor, and produced using a proprietary transcription process developed with NPR. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of NPR’s programming is the audio record.