Learn about some of the most common causes for hearing loss and how you can protect your ears from them, from author David Owen. You’ll also learn about how woolly mammoth DNA has given us new insight into what made them go extinct.
Learn about some of the most common causes for hearing loss and how you can protect your ears from them, from author David Owen. You’ll also learn about how woolly mammoth DNA has given us new insight into what made them go extinct.
Additional resources from David Owen:
Mammoth DNA gives clues as to what wiped them out by Grant Currin
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Find episode transcript here: https://curiosity-daily-4e53644e.simplecast.com/episodes/protecting-yourself-from-hearing-loss-w-david-owen-and-why-woolly-mammoths-went-extinct
CODY: Hi! You’re about to get smarter in just a few minutes with Curiosity Daily from curiosity-dot-com. I’m Cody Gough.
ASHLEY: And I’m Ashley Hamer. Today, you’ll learn about some of the most common causes for hearing loss and how you can protect your ears from them, from author David Owen. You’ll also learn about how resurrected woolly mammoth DNA has given us new insight into what made them go extinct.
CODY: Let’s satisfy some curiosity.
You’re never too young to start protecting your ears. And you’re about to learn some tips for protecting yourself from hearing loss. Our guest is David Owen, author of the new book “Volume Control: Hearing in a Deafening World.” You can hear the first part of our conversation on last Wednesday’s episode of Curiosity Daily, which there’s a link to in today’s show notes. And now, part 2.
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Again, David Owen is the author of the new book “Volume Control: Hearing in a Deafening World.” You can find a link to pick up the book in today’s show notes, and next week he’ll be back to talk about what to do once your hearing does start to go away — including what technology we have to help.
There used to be a ton of woolly mammoths on Earth, but the last 12,000 years were pretty rough on them. What you might not know is that even after most of them died out, a few populations hung around for another several thousand years — like, after humans had invented writing. The woolly mammoth eventually went extinct, and thanks to recent DNA analysis, we have new insight into what finally killed them.
Most woolly mammoths died at the end of the Pleistocene, around 12,000 years ago. At that point, climate change made life impossibly difficult for lots of big animals that had evolved to live in cold, dry climates. But there were two small islands between modern-day Russia and Alaska where these ancient behemoths managed to survive. After all of their brethren had disappeared, the mammoths on St. Paul Island and Wrangel [RANG-gull] Island persisted for thousands of more years. Humans were spreading across the globe, inventing writing, and building the first pyramids, and these last remaining woolly mammoths were still holding down the fort.
Rising sea levels killed off the St. Paul Island herd about 5,600 years ago, leaving only the Wrangel Island herd. With only about 400 individuals, that population managed to survive for another 1,600 years.
Now, researchers have figured out — pretty much — what happened to those last surviving mammoths. Scientists have already analyzed a lot of mammoth DNA, so it was fairly simple for these researchers to compare the genomes of Wrangel Island mammoths to those of two other mammoths and three modern Asian elephants. The DNA of these other species is similar enough for the researchers to spot anything weird about the Wrangel Island mammoths.
It turns out that thousands of years of inbreeding can have extinction-level consequences. The researchers found a ton of unusual mutations in the Wrangel Island mammoth genome. Some of the mutations probably caused problems with neurological development, male fertility, insulin signaling, and even their sense of smell. One of the researchers said that the Wrangel Island mammoths were probably, quote, “unable to smell the flowers that they ate,” end quote.
As distant relatives were forced to breed to keep the population going, detrimental mutations kept accumulating. The researchers are pretty sure that some of the mutations prevented a lot of males from producing functional sperm, which made the breeding population dwindle even more.
Even though we can’t pinpoint what happened to the very last individual, this study makes a strong case that woolly mammoths finally went extinct because, in the end, there just weren’t enough of them.
Let’s recap the main things we learned today
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CODY: Today’s last story was written by Grant Currin, and edited by Ashley Hamer, who’s the managing editor for Curiosity Daily.
ASHLEY: Today’s episode was produced and edited by Cody Gough.
CODY: Join us again tomorrow to learn something new in just a few minutes.
ASHLEY: And until then, stay curious!