Mammoth, DNA, Mammuthus primigenius, Evolution, Sequencing The Oldest DNA Ever Found
And determining the contents of that ancient genetic material can be incredibly useful for understanding evolution.. But ancient DNA has a shelf life. Its a complex molecule and it doesnt last forever, though it can stick around a surprisingly long time., The oldest known DNA dates back hundreds of thousands of years., Its been predicted that DNA might be able to survive more than a Million years, but thats never been confirmed. Until now., A study published this week in the journal. Nature reports, ancient DNA from mammoth teeth dating as far back as one point: two million years., Its the oldest DNA ever sequenced, and it has revealed some big surprises about mammoth. Evolution. Mammoths are ancient elephants and two species woolly mammoths and Columbian mammoths were both important. During the later parts of the Ice, Age. Woolly mammoths lived in cold high latitude regions of North America and Eurasia. Columbian mammoths were much bigger and lived only in North America., But there were many other species before them, including the species thought to be their ancestors steppe. Mammoths. In this study, the researchers examined three mammoth molars from frozen soils in Siberia.. One of the teeth comes from a very ancient woolly mammoth, while the other two are either from steppe mammoths or something very similar.. The three teeth range in age, from seven hundred thousand, to one point: two million years old. There was DNA locked up inside these teeth, though the passing of a million years had taken a toll on its integrity.
. However, with some very careful methods, the researchers were able to reconstruct significant chunks of each mammoths genome.. Those chunks included portions that geneticists use to trace the descent of evolutionary lineages over time.. This is a huge technical achievement that confirms that DNA can be extracted from fossils. Over one million years old, but it also shakes up our understanding of mammoth evolution. See. Researchers had thought that there was only one group of mammoths in Siberia. One point: two million years ago., However, by comparing the DNA sequences from the two older teeth, the researchers determined that they were different enough to be two separate lineages., Which is to say two related, but apparently distinct, groups. According to the DNA one of those lineages is The ancestor of woolly mammoths, but the second is a whole other lineage of mammoths that we didnt know about.. Even more surprisingly, that other separate group was a partial match for Columbian mammoths and a partial match for woolly mammoths.. This means that early woolly mammoths must have interbred, with this unknown group at some point to produce Columbian mammoths. Theyre not descended from a single ancestral species instead theyre hybrids. This research tells us that we have a lot more to learn about mammoth evolution., But we now know that ancient DNA has the potential to help us uncover those mysteries even beyond a million years, ago. Speaking of finding unexpected things in frozen landscapes. Another new study in the journal Frontiers in Marine Science reports a group of animals living in an Antarctic environment where scientists really really didnt expect to find them.
. You probably know that Antarctica is covered in ice, but its also surrounded by it. All around the frozen continent are ice shelves huge slabs of ice that float on the oceans surface.. As you might imagine, the world beneath an ice shelf is cold and dark., So scientists have long suspected that not much animal life could survive down. There. All theyve found beneath ice sheets so far are a few swimming or crawling critters.. But this new study uncovered a big surprise: animals that spend their lives in one spot.. Scientists had believed that type of lifestyle was totally impossible beneath an ice sheet.. The researchers drilled holes several hundred meters through the Filchner Ice Shelf and sent a camera down to see what was below. On the seafloor 1200 meters. Beneath the surface. They spotted a big boulder that was covered in animal life and all of those animals were sessile attached to the rock.. With the footage they got. The researchers werent able to identify all of the animals they saw, but most of them seemed to be sponges or sponge. Like organisms., The researchers believe these animals are filter feeders, they get their food from nutrients floating in the water., Usually those floating nutrients drift down from ecosystems higher in the water thanks to photosynthesizing plankton and the animals that eat them., But photosynthesis requires sunlight and theres. None of that beneath the ice shelf., The researchers estimate that any nutrients traveling on the local water currents would need to make a journey of up to fifteen hundred kilometers to reach this boulder from the nearest sun lit habitat.
Its also possible that the animals could be Feeding on nutrients within the sediments melting, slowly out of the ice shelf above them, but its hard to know for sure.. In fact, a lot is hard to know about this boulder community.. This is the first known example of a sessile community under an ice shelf.. The researchers are hopeful that more study might help them identify the species present.. They also want to find out what these creatures are eating and how they got there in the first place.. It could be that this ecosystem is better connected to the outside world than we realize or that they really are specially adapted for this dark frigid habitat with nothing to eat., Either way it means theres more to life under the ice shelves than we knew so much More that we can stumble on it in places we really dont expect Thanks for watching this edition of SciShow News. SciShow is brought to you by our amazing, wonderful, fantastic community of patrons. Patrons get access to neat perks from monthly Fancy Facts to our community Discord.. If youd like to join check out patreon.