Thousands of years after its extinction, this massive mammoth with its gigantic tusks is still a matter of debate. Because how accurate is dating based on DNA material really?
It is still not clear why and when mammoths disappeared. Was it because of climate change, which changed their habitat, or did humans kill the elephants? And when exactly did all this happen?
Initially, paleontologists assumed that mammoths became extinct about 10,000 years ago (except for a group of dwarf mammoths on Russia’s Wrangel Island in the Arctic Ocean), but a recent study in natureWho analyzed DNA material from the remains of mammoths and about 1,500 plants in the Arctic, arrived at a different timeline: Only 3,900 years ago were the last mammoths to have turned off the lights and the cause of the extinction was because the climate had become wetter. The landscape changed rapidly from steppe and tundra grasslands to forested wetlands. This would kill the Big Haired Shepherd.
Paleontologist Joshua Miller University of Cincinnati However, he does not agree with this analysis. He points out that dating DNA material from sedimentary deposits can be misleading because, under certain conditions, genetic material is not immortalized in sediments until thousands of years after death. In an article too in nature popped upMiller refutes the claims of the previous study.
DNA dating is misleading
“The problem is, you have no idea how old this DNA is,” Miller explains. “Sedimentary deposits are complex. Biological material of different ages is often buried together.” Researchers have many tools to date sediments and the materials they contain, Miller says, but they aren’t always successful. “We can date all kinds of things using radiocarbon (C14 dating): bones, teeth, coal, leaves. This is a very powerful and accurate method. But at the moment we cannot independently date the DNA material in the sediments.”
From recent discoveries, such as a baby mammoth found in Canada this year, we know that many Ice Age animals that died out tens of thousands of years ago could be mummified in the dry, cold environment of the Arctic. But Miller explains that researchers can’t tell whether this DNA, which is preserved in the sediment, comes from a living or dead animal.
Traces of “fresh” DNA long after death
“DNA is constantly being shed by organisms,” Miller said. “If the conditions are right, the animal will still release DNA material long after it has died. In places where decomposition is agonizingly slow, this causes genetic material from long-dead or even long-extinct species to be immortalized later in the surrounding sediments.” In the Arctic and other cold regions, for example, it can take thousands of years for organic matter to decompose.”
His study suggests that the mummified remains of elephant seals near Antarctica are sometimes more than 5,000 years old. “In some remote areas of the Arctic, 2,000-year-old antlers are found on the surface,” says the paleontologist. However, the most recent mammoth fossils found in Siberia were buried in the permafrost around 11,000 years ago. It is therefore more likely that, as previously thought, mammoths became extinct around that time.
How old is the shell?
From his field of work as a marine researcher, co-author Carl Simpson explains why dating ancient specimens is so difficult. Shells can remain on the sea floor for thousands of years. “The shells on the beach may have contained animals that died recently, but these shellfish may have been dead for thousands of years, and it’s hard to tell the difference,” says Simpson. “The same thing happens in vertebrates, too.”
According to Miller, the question remains what impact humans will have on the global extinction of mammoths. It is known that people used fire around that time, which could dramatically change the landscape. People also hunted mammoths and made use of their ivory tusks. All of which may have contributed to Elephant’s evocative demise. “They look a lot like the animals you see today in the wild and in zoos,” says Miller. “We can almost touch them. That makes mammoths so attractive. To many people, they are the megafauna banners of the Ice Age.”
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