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  • thanks to a brilliant for supporting this episode of Sideshow, go to brilliant dot org's slash sideshow.

  • To learn more, scientists who study our planet's past often have to piece together some pretty desperate clues.

  • Fossils, artifacts and other lines of evidence can often be few and far between, so you can imagine how handy it would be to have an animal that collects clues from its environment and stores them away in a nice, convenient spot.

  • Meet the rock high racks of Africa, a little animal that scientists love because it preserves pieces of the past in piles of poo these furry little mammals live in and among rock crevices.

  • It may look like rodents, but research has found that their closest relatives are actually elephants and manatees.

  • Rock Iraq's is live in large colonies, and those colonies have developed the peculiar habit of using what are called communal latrines, which is exactly what it sounds like.

  • A designated spot that everyone in the colony uses for going to the bathroom.

  • These rocky toilets tend to be located in safe, sheltered areas, so a single latrine can last quite a while.

  • In some cases, ah, latrine might be used by the same colony over hundreds of generations, forming a heap of waste that can be used force centuries.

  • The end result is a midden, ah, multilayered collection of fecal pellets and a substance called Hirase IAM, or the dried remains of Hi Rex urine, which is something that was worth giving a name, too.

  • Because here's the thing.

  • The higher axes air only trying to keep their colony clean.

  • But they unknowingly capture plant and animal remains from their nearby environment and preserve them in a time capsule, which makes thes poo piles a goldmine for researchers.

  • Normally, when we want to learn about how an ecosystem has changed over time, we look at biological and chemical evidence preserved in fossils, ice cores or limestone cave formations.

  • But in certain dry, rocky parts of Africa, those types of evidence are pretty rare.

  • Pyrex is, however, are common, and so is their excrement, which has led to a seriously impressive body of higher axe waste literature.

  • Not only do hire axe middens preserve environmental data from the time the waste was created, they often do so inconvenient chronological layers.

  • Each time a higher axe lays down a fresh coat of urine.

  • It seeps across rocks and around the poop pellets, and when it dries, it cement into a new layer of Hirase IAM crust.

  • In some places, higher axe millions can be over a meter thick and several meters across and under the right conditions.

  • A midden can become petrified and persist long after the hire ex colony has moved off.

  • They can contain millennia of environmental history and the oldest known higher axe middens preserve waste that's 50,000 years old.

  • Generally higher axe middens contain a lot of plant material, since that's what the little guys eat.

  • And those plants can tell us a lot, especially about the climate and growing conditions that existed when they were eating.

  • Like a 2010 study that looked at an increase in leafy plants relative to grasses in two millions over the past 10,000 years or so, this adjusted the climate may have been drying out enough to make it hard for hire axes to find lush, tasty grass to eat.

  • And there's more in those middens than just the plants.

  • Higher axes.

  • Eight tolling grains are famously durable, and they can be preserved in middens when they drift in from the air or carried on higher axes for.

  • In a 2011 study, researchers collected MIDAN data from southern Africa spending almost 20,000 years of history this time looking for ancient Paul in the pollen revealed changes through time in Fain Boss, scrubby vegetation that makes up a unique type of plan ecosystem in southern Africa.

  • The pollen record showed that past shifts in climate affected lowland fain boss more dramatically than the mountain varieties, data that might help researchers protect these endangered plants in the future.

  • Research in higher axe middens has uncovered not only plant remains but also ancient DNA from animals that shared the higher exes habitat and microscopic remains of charcoal that reveal local fire history.

  • And all of this data can be combined with other information to reconstruct the history of Africa and even of our own species.

  • The 2018 study compared climate information from higher axe middens, toe archaeological records of human activity in South Africa over the last 20,000 years or so.

  • The data showed that as the regional climate grew, dryer coming out of the ice age and large prey became harder to find, local humans changed their survival strategies.

  • In many ways, they became less picky about their resource is and went after more small animals like hares and tortoises, and they made their tools out of lower quality, more common types of rock.

  • These changes reflect the amazing adaptability of our species in response to changing conditions, and this information is brought to us by the latrine, a legacy of the higher axes that lived alongside our ancestors.

  • Africa is a continent of particular importance to the history of our own and many other species.

  • And while there are mid in making mammals on other continents, it's higher axes that provide a unique insight into Africa's past.

  • Fire axes and other midden building species have been creating ecological time capsules for tens of thousands of years.

  • There, the unwitting field assistance for today's scientists.

  • They might not sound like the most glamorous job digging through thousands of layers of an ancient latrine.

  • But for scientists seeking to understand our world's history, there's nothing better than a bit of preserved higher axe based.

  • But you don't have to go digging through higher X millions just to learn stuff for the rest of us that there is brilliant dot org's.

  • If you like to challenge yourself every day, you might like there daily challenges really and offers daily challenges, which are questions about science concepts that challenge you to exercise your mind every day.

  • None on high racy, um, that we know of so far, but we'll keep you posted.

  • Each question comes with illustrations, animations or interactive visualizations and all the context you need to solve the problem yourself.

  • And if you find it, piques your interest.

  • Each one also ties back to ah, whole course offered by Brilliant, you can access each day's challenge for free, but a premium membership unlocks the whole archive and, conveniently, the 1st 200 people to sign up.

  • A brilliant dot org's slash cy show will get 20% off an annual premium subscription, so check it out and see if it's right for you.

thanks to a brilliant for supporting this episode of Sideshow, go to brilliant dot org's slash sideshow.

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B1 中級

鬣狗如何在便溺中保存過去的記憶? (How Hyraxes Preserve the Past in Poo)

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    林宜悉 發佈於 2021 年 01 月 14 日
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