Oldest DNA on record reveals an amazing lost world
The oldest DNA ever discovered, including animals, plants, and microbes, was found in sediment excavated from the northernmost tip of Greenland near the mouth of an Arctic Ocean fjord. This discovery sheds light on an astonishing forgotten world at this far-flung frontier.
A wide variety of animals, including mastodons, reindeer, hares, lemmings, and geese, as well as plants like poplar, birch, and thuja trees, as well as microorganisms like bacteria and fungi, had DNA fragments found, according to researchers on Wednesday. A kind of blueprint for life, DNA is the self-replicating substance that carries genetic information in living things.
A close relative of elephants, the mastodon lived in North and Central America before going extinct, along with many other huge Ice Age creatures, about 10,000 years ago. The finding demonstrates that its range was greater than previously thought.
“The mastodon was a great surprise. It’s never been found on Greenland before. However, the greatest surprise was this unique ecosystem of Arctic and temperate species mixed together with no modern analog,” Eske Willerslev, director of the Lundbeck Foundation GeoGenetics Center and principal investigator of the study that appeared in Nature, made this statement.
Despite the fact that ancient DNA is highly perishable, the study demonstrated that it can endure longer than previously thought under the correct circumstances, in this case, permafrost. Willerslev stated that he would no longer be shocked to discover DNA dating back at least 4 million years.
The 41 organic-rich sand samples were collected from five places on the Peary Land peninsula that projects into the Arctic Ocean. The samples’ DNA was extracted and sequenced. Clay and quartz in the silt were mined for microscopic DNA fragments. More than 100 different kinds of animals and plants were identified.
The samples were first discovered in 2006, but prior attempts to find DNA were unsuccessful. Since then, techniques for obtaining ancient DNA have advanced, finally leading to a breakthrough.
According to Willerslev, fragmentary DNA cannot be utilised to bring back extinct species, unlike in the “Jurassic Park” novels and movies, but it may hold the key to understanding how plants might adapt to a warming climate. The oldest known DNA was taken from the molar of a mammoth, a related of the elephant that lived in northeastern Siberia and was frozen in permafrost for up to 1.2 million years. In contrast, Homo sapiens, our species, emerged some 300,000 years ago.
The majority of what is known about ancient species comes from analysing fossils, but there are limits to what they can tell us, especially when it comes to genetic ties and characteristics. In this situation, ancient DNA is extremely useful.
A substantial ice sheet covers much of present-day Greenland, with certain coastal regions remaining ice-free. The research area is regarded as a polar desert. However, according to to study lead author Kurt Kjaer of the University of Copenhagen, Greenland’s typical temperatures were 20 to 30 degrees Fahrenheit (11 to 17 degrees Celsius) higher 2 million years ago. The prevalence of marine animals, such as horseshoe crabs and green algae, among the DNA, found, the researchers claimed, suggested warmer temperatures.
This ancient habitat, which includes an open boreal forest with trees, shrubs, and smaller plants as well as a plethora of creatures, has been fully exposed by the DNA. It did not specify which huge predators were there, but research co-author Mikkel Pedersen of the University of Copenhagen speculates that these might have included wolves, bears, and saber-toothed cats.
The University of Copenhagen professor and study co-author Nicolaj Larsen said the team is searching northern Canada for even ancient DNA.
