1 00:00:01,920 --> 00:00:06,720 Speaker 1: Welcome to Brainstuff, a production of iHeart Radio, Hey brain 2 00:00:06,760 --> 00:00:11,000 Speaker 1: Stuff Lauren Vogelbaum. Here, if we picture the demise of 3 00:00:11,039 --> 00:00:13,680 Speaker 1: the wooly mammoths, we might think of a herd of 4 00:00:13,840 --> 00:00:17,880 Speaker 1: shaggy elephants pursued by prehistoric humans, spears in hand and 5 00:00:17,960 --> 00:00:21,120 Speaker 1: dinner on the brain. And that may well be how 6 00:00:21,200 --> 00:00:24,560 Speaker 1: the vast majority of the massive herbivores met their fate. 7 00:00:25,120 --> 00:00:27,560 Speaker 1: But a study published in the journal Proceedings of the 8 00:00:27,640 --> 00:00:30,640 Speaker 1: National Academy of Science reports that one of the world's 9 00:00:30,680 --> 00:00:34,280 Speaker 1: final populations of wooly mammoth's was ultimately killed by a 10 00:00:34,400 --> 00:00:38,920 Speaker 1: lack of fresh drinking water. It's long been thought that 11 00:00:38,960 --> 00:00:41,880 Speaker 1: most of the world's wooly mammoth populations when extinct due 12 00:00:41,880 --> 00:00:45,080 Speaker 1: to a combination of climate change and human hunting, with 13 00:00:45,200 --> 00:00:47,560 Speaker 1: the last of their kind dying off on the mainland 14 00:00:47,640 --> 00:00:51,800 Speaker 1: around eleven thousand years ago, but a few stragglers held on. 15 00:00:52,600 --> 00:00:56,279 Speaker 1: For instance, one population survived until about four thousand, three 16 00:00:56,360 --> 00:00:59,040 Speaker 1: hundred years ago on a remote chunk of Arctic land. 17 00:01:00,000 --> 00:01:02,600 Speaker 1: The study in question dates the end of another nearby 18 00:01:02,640 --> 00:01:05,160 Speaker 1: group to five thousand, six d and fifty years ago, 19 00:01:05,319 --> 00:01:08,520 Speaker 1: give or take eighty years. The mammoths of Saint Paul 20 00:01:08,600 --> 00:01:11,679 Speaker 1: Island in the Bearing Sea between today's Russia and the 21 00:01:11,760 --> 00:01:15,080 Speaker 1: United States. The discovery is being touted as the most 22 00:01:15,120 --> 00:01:20,120 Speaker 1: accurately dated prehistoric extinction to date. As the post Ice 23 00:01:20,160 --> 00:01:23,840 Speaker 1: Age world warmed and sea levels rose, it seemed that 24 00:01:23,920 --> 00:01:27,640 Speaker 1: Saint Paul Island shrank in area, and its freshwater lakes 25 00:01:27,640 --> 00:01:32,000 Speaker 1: that sustained mammoths became scarcer. The researchers discovered something of 26 00:01:32,000 --> 00:01:35,240 Speaker 1: a domino effect, as more mammoths and other animals crowded 27 00:01:35,240 --> 00:01:39,880 Speaker 1: around fewer freshwater sources and trampled more vegetation around the lakes. 28 00:01:40,720 --> 00:01:43,720 Speaker 1: This contributed to an increase in dirt and sediment flowing 29 00:01:43,760 --> 00:01:46,760 Speaker 1: into the lakes, making what little water remained even less 30 00:01:46,760 --> 00:01:50,880 Speaker 1: suitable for drinking. In response to similar situations, modern day 31 00:01:50,880 --> 00:01:53,480 Speaker 1: elephants have been seen digging holes near to a sediment 32 00:01:53,520 --> 00:01:56,520 Speaker 1: filled lake in search of clean drinking water, a short 33 00:01:56,640 --> 00:01:59,760 Speaker 1: term fix, but one where the earth dug up muddies 34 00:01:59,800 --> 00:02:04,160 Speaker 1: the primary lake even more. The Asian elephant is the 35 00:02:04,200 --> 00:02:08,800 Speaker 1: wooly mammoth's closest living relative, though, if you were picturing 36 00:02:08,800 --> 00:02:12,040 Speaker 1: a group of towering mammoths, true to their names, staggering 37 00:02:12,080 --> 00:02:15,239 Speaker 1: around in search of drinking water. Tweak that image a bit. 38 00:02:15,720 --> 00:02:18,680 Speaker 1: The offshoot populations of wooly mammoths like those on St. 39 00:02:18,720 --> 00:02:22,320 Speaker 1: Paul were dwarf descendants of the mainstream wooly mammoth. They 40 00:02:22,320 --> 00:02:24,600 Speaker 1: were only a little taller than a full grown human. 41 00:02:24,960 --> 00:02:29,480 Speaker 1: Thanks to generations of inbreeding and evolutionary responses to island environments, 42 00:02:30,720 --> 00:02:33,480 Speaker 1: the scientists were able to discern how the lake environment 43 00:02:33,600 --> 00:02:36,880 Speaker 1: changed by analyzing core samples extracted from the lake bed. 44 00:02:37,520 --> 00:02:40,600 Speaker 1: They also tracked the change over time in fungal spores 45 00:02:40,720 --> 00:02:43,840 Speaker 1: known to grow in the dung of large mammals like mammoths. 46 00:02:44,560 --> 00:02:48,480 Speaker 1: They're particularly confident in the environmental aspect of their conclusions 47 00:02:48,520 --> 00:02:52,000 Speaker 1: because the island became isolated from the mainland about fourteen 48 00:02:52,000 --> 00:02:55,800 Speaker 1: thousand years ago, and there's no evidence humans ever lived 49 00:02:55,800 --> 00:02:59,359 Speaker 1: there and affected the mammoth population. The first humans to 50 00:02:59,400 --> 00:03:07,480 Speaker 1: step foot on island arrived by boat in seven CE. 51 00:03:08,919 --> 00:03:11,640 Speaker 1: Today's episode was written by Christopher Hasseiotis and produced by 52 00:03:11,639 --> 00:03:13,919 Speaker 1: Tyler Clang. For more on this and lots of other 53 00:03:13,960 --> 00:03:17,000 Speaker 1: mammoth topics, visit how stuff works dot com. Brain Stuff 54 00:03:17,040 --> 00:03:19,359 Speaker 1: is production of I Heart Radio. For more podcasts for 55 00:03:19,400 --> 00:03:22,320 Speaker 1: my Heart Radio visit the I heart Radio app, Apple podcasts, 56 00:03:22,400 --> 00:03:24,240 Speaker 1: or wherever you listen to your favorite shows.