Speaker 1: Welcome to brain Stuff production of iHeart Radio, Hey, brain Stuff,
Speaker 1: lor and Vogel Bomb here in. A wally mammoth carcass
Speaker 1: was discovered in Siberia near the coast of the Left
Speaker 1: of Sea. Nicknamed Yucca, this specimen of the long extinct
Speaker 1: beast died around twenty eight thousand years ago, yet her
Speaker 1: body was astonishingly well preserved, complete with patches of reddened
Speaker 1: for a brain that was largely intact and nucleus like
Speaker 1: cell structures. So how did her body last so long
Speaker 1: without rotting away? The short answer is Yuka was frozen,
Speaker 1: but not inside some glacier or iceberg. After death, Yuca
Speaker 1: became encased in a layer of what's known as permafrost.
Speaker 1: Let's break down what that is. As we know, water
Speaker 1: freezes at thirty two degrees fahrenheit or zero degrees celsius.
Speaker 1: Permafrost is any ground materials such as soil, sediment, and rock,
Speaker 1: that remains at or below freezing temperatures for at least
Speaker 1: two consecutive years. About scent of all the land area
Speaker 1: in the Northern Hemisphere is known to contain permafrost. It
Speaker 1: was American paleontologist Simon W. Mueller who originally coined the
Speaker 1: term permafrost, a portmanteau of the words permanent and frost.
Speaker 1: Despite that name, permafrost doesn't last forever. Thanks to climate change,
Speaker 1: it's been thawing in large quantities. This has serious ramifications
Speaker 1: for both the environment and the economy. Generally speaking, permafrost
Speaker 1: tends to occur in places where the average air temperature
Speaker 1: is zero degrees celsius or lower every year. According to
Speaker 1: the National Snow and Ice Data Center, most of the
Speaker 1: northern hemispheres, permafrost sits between the high latitudes of sixty
Speaker 1: and sixty degrees north Siberia, Canada, Alaska, and parts of
Speaker 1: Scandinavia are loaded with this frigid turf. Further south, permafrost
Speaker 1: tends to be found in high elevation areas like the
Speaker 1: Tibetan Plateau and this was Alps. Permafrost isn't as widespread
Speaker 1: below the equator, but it does underlie parts of New Zealand,
Speaker 1: the and Mountains, and Antarctica. Just as its locations vary,
Speaker 1: so does its composition. It's not uniform. Some sections are
Speaker 1: ice free while others are made up of more than
Speaker 1: thirty ice. Likewise, the depth, age and extent of permafrost
Speaker 1: can vary widely. Oftentimes, permafrost sits beneath an active layer
Speaker 1: of ground, that is, a layer that thaws and refreezes seasonally.
Speaker 1: The permafrost itself can measure anywhere from less than three
Speaker 1: feet that's one meter thick to more than five thousand
Speaker 1: feet or fift thick, and it can get patchy. Northern
Speaker 1: Alaska occupies a continuous permafrost zone that means permafrost underlies
Speaker 1: more of the local terrain, but at lower latitudes it's
Speaker 1: a different story. Pretty Much everything south of the Brooks
Speaker 1: Mountain Range sits in a discontinuous permafrost zone. Here, permafrost
Speaker 1: resides under a smaller percentage of the land's surface. That's
Speaker 1: partially because, as counterintuitive is it may sound, snow is
Speaker 1: a really good insult, so when thick blankets of snow
Speaker 1: stick around all year long, they might keep the ground
Speaker 1: too warm for permafrost. Likewise, in spots where permafrost already exists,
Speaker 1: insulating layers of surface level snow are liable to heat
Speaker 1: it up. But while snow is an impediment, Pete is
Speaker 1: a boon wide spread in and around the southern Arctic
Speaker 1: pete is a kind of ground material that's made up
Speaker 1: of partially decayed organic matter like mosses or swamp plants.
Speaker 1: By and large, the ground beneath it is kept cool
Speaker 1: shielded from solar heat. Thus pete safeguards permafrost. Evergreen forests
Speaker 1: lend a helping hand too. With their thickly needled branches.
Speaker 1: Pine trees limit the amount of sunlight and snow that
Speaker 1: hits the surface. In the process, the evergreens help keep
Speaker 1: permafrost from thawing, so permafrost is common below the clustered
Speaker 1: pines and high elevation and high altitude areas. The arrangement
Speaker 1: is mutually beneficial. Since liquid water can't seep through hard permafrost,
Speaker 1: it acts like a drainage barrier. Unfrozen water that's absorbed
Speaker 1: into the active layer gets trapped there, barred from traveling
Speaker 1: deeper into the earth. This water sustained some of the
Speaker 1: plants that live at the surface. Although not all permafrost
Speaker 1: sticks around more than a couple of years, some is
Speaker 1: quite old. At minimum, the permafrost in Prudo Bay, Alaska
Speaker 1: is thought to be five hundred thousand years of age,
Speaker 1: and some of the permafrost beneath the Canadians Yukon territory
Speaker 1: could be more than seven hundred thousand years old. Inside
Speaker 1: the ladder, scientists found an ancient horse leg complete with
Speaker 1: DNA samples. Permafrost can keep all kinds of organic matter
Speaker 1: preserved over long periods of time. In Russian scientists regenerated
Speaker 1: live hunter plants from ice age fruits that have been
Speaker 1: encased in permafrost for about thirty thousand years. Unfortunately, as
Speaker 1: permafrost thaws, the trapped organic material decomposes, releasing carbon and
Speaker 1: methane into the atmosphere. Those gases exacerbate climate change, and
Speaker 1: the bad news is According to a twenty nineteen study
Speaker 1: published in Nature, Community Patians, various permafrost deposits around the
Speaker 1: world have warmed up by a couple degrees between the
Speaker 1: years two thousand seven and two thousand sixteen. Right now,
Speaker 1: approximately one point seven billion tons of carbon is trapped
Speaker 1: in permafrost. Scientists don't know how much of this will
Speaker 1: be released into the atmosphere if current thawing trends continue,
Speaker 1: or how quickly it will escape, but some projections are
Speaker 1: not encouraging. To make matters worse. When permafrost thaws, it
Speaker 1: can destabilize the landscape. In the city of Norlis, Russia alone,
Speaker 1: more than one hundred residential buildings have been damaged because
Speaker 1: the once solid permafrost beneath them is softening. The warming
Speaker 1: of permafrost has also triggered landslides, drained lakes, and torn
Speaker 1: roads apart, it's yet another reason to be concerned about
Speaker 1: our contributions to climate change. But to end on a
Speaker 1: positive note, remember the wooly mammoth Yucca found in Siberian permafrost.
Speaker 1: She was so well preserved that in early twenty nineteen,
Speaker 1: scientists were able to extract eighty eight nucleus like structures
Speaker 1: from her cells an attempt to coax them back to life.
Speaker 1: The team injected the nuclei into mouse ovarian cells, and
Speaker 1: while the cells never fully divided, they did complete the
Speaker 1: process called spindle assembly, which is a step where chromosomes
Speaker 1: attached to spindle structures before the parents cell breaks into
Speaker 1: two daughter cells. Perhaps, as genetics progresses will be able
Speaker 1: to help the process along. Today's episode was written by
Speaker 1: Mark Mancini and produced by Tyler Clang. Brain Stuff is
Speaker 1: a production of I Heart Radio's How Stuff Works. For
Speaker 1: more in this and lots of other cool topics, visit
Speaker 1: our home planet, how Stuff Works dot com and for
Speaker 1: more podcasts. For my heart Radio, visit the iHeart Radio app,
Speaker 1: Apple Podcasts, or wherever you listen to your favorite shows,