Speaker 1: Welcome to Brainstuff, a production of iHeart Radio, Hey brain
Speaker 1: Stuff Lauren Vogelbaum. Here, if we picture the demise of
Speaker 1: the wooly mammoths, we might think of a herd of
Speaker 1: shaggy elephants pursued by prehistoric humans, spears in hand and
Speaker 1: dinner on the brain. And that may well be how
Speaker 1: the vast majority of the massive herbivores met their fate.
Speaker 1: But a study published in the journal Proceedings of the
Speaker 1: National Academy of Science reports that one of the world's
Speaker 1: final populations of wooly mammoth's was ultimately killed by a
Speaker 1: lack of fresh drinking water. It's long been thought that
Speaker 1: most of the world's wooly mammoth populations when extinct due
Speaker 1: to a combination of climate change and human hunting, with
Speaker 1: the last of their kind dying off on the mainland
Speaker 1: around eleven thousand years ago, but a few stragglers held on.
Speaker 1: For instance, one population survived until about four thousand, three
Speaker 1: hundred years ago on a remote chunk of Arctic land.
Speaker 1: The study in question dates the end of another nearby
Speaker 1: group to five thousand, six d and fifty years ago,
Speaker 1: give or take eighty years. The mammoths of Saint Paul
Speaker 1: Island in the Bearing Sea between today's Russia and the
Speaker 1: United States. The discovery is being touted as the most
Speaker 1: accurately dated prehistoric extinction to date. As the post Ice
Speaker 1: Age world warmed and sea levels rose, it seemed that
Speaker 1: Saint Paul Island shrank in area, and its freshwater lakes
Speaker 1: that sustained mammoths became scarcer. The researchers discovered something of
Speaker 1: a domino effect, as more mammoths and other animals crowded
Speaker 1: around fewer freshwater sources and trampled more vegetation around the lakes.
Speaker 1: This contributed to an increase in dirt and sediment flowing
Speaker 1: into the lakes, making what little water remained even less
Speaker 1: suitable for drinking. In response to similar situations, modern day
Speaker 1: elephants have been seen digging holes near to a sediment
Speaker 1: filled lake in search of clean drinking water, a short
Speaker 1: term fix, but one where the earth dug up muddies
Speaker 1: the primary lake even more. The Asian elephant is the
Speaker 1: wooly mammoth's closest living relative, though, if you were picturing
Speaker 1: a group of towering mammoths, true to their names, staggering
Speaker 1: around in search of drinking water. Tweak that image a bit.
Speaker 1: The offshoot populations of wooly mammoths like those on St.
Speaker 1: Paul were dwarf descendants of the mainstream wooly mammoth. They
Speaker 1: were only a little taller than a full grown human.
Speaker 1: Thanks to generations of inbreeding and evolutionary responses to island environments,
Speaker 1: the scientists were able to discern how the lake environment
Speaker 1: changed by analyzing core samples extracted from the lake bed.
Speaker 1: They also tracked the change over time in fungal spores
Speaker 1: known to grow in the dung of large mammals like mammoths.
Speaker 1: They're particularly confident in the environmental aspect of their conclusions
Speaker 1: because the island became isolated from the mainland about fourteen
Speaker 1: thousand years ago, and there's no evidence humans ever lived
Speaker 1: there and affected the mammoth population. The first humans to
Speaker 1: step foot on island arrived by boat in seven CE.
Speaker 1: Today's episode was written by Christopher Hasseiotis and produced by
Speaker 1: Tyler Clang. For more on this and lots of other
Speaker 1: mammoth topics, visit how stuff works dot com. Brain Stuff
Speaker 1: is production of I Heart Radio. For more podcasts for
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