Greenland really was green: Ancient DNA told about a rich ecosystem

(ORDO NEWS) — DNA is a molecule that contains the genetic instructions. Biological information is stored in it in the form of a genetic code. By deciphering this code, scientists can get a lot of information about the host of the molecule.

Because DNA has a half-life of more than 500 years and a complete decay at -5 degrees Celsius takes almost 7 million years, scientists can sequence (decode) ancient DNA from animals and plants that died out hundreds of thousands or even several million years ago.

Until recently, the oldest DNA ever discovered was that of a 1.2 million year old mammoth. It was discovered in animal bones in 2001. Later, scientists managed to find DNA fragments 2 million years old in Greenland, which have now been sequenced. Their deciphering showed

Ancient DNA in Greenland

Considering that the decay time of DNA depends on the ambient temperature, the Arctic is the best place to search for ancient genetic sequences. Since 2006, 41 DNA samples have already been found here.

They are all preserved in a sedimentary slab belonging to the Cape Cobenhavn Formation. The plate is located in the northern part of Greenland, on a piece of land called the land of Piri. Due to the dryness of the climate, this area is not covered with ice, which simplifies the search for DNA.

The molecules with the genetic code found here were left behind by ancient animals, plants and even microbes that once lived on this island. Thanks to the permafrost, they managed to be perfectly preserved, which allowed scientists to draw conclusions about the former Greenland ecosystem and climate change.

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DNA samples 2 million years old scientists found on the ground of Piri

Ecosystem of ancient Greenland

As an international group of paleogenetics and geologists reports in the journal Nature, they have examined ancient DNA and compared it with the genetic sequences of existing animals and plants. As a result, they managed to find out who owned these molecules two million years ago.

According to the results of the study, hares, reindeer, hamsters, various birds including geese, etc. once lived on the territory of Greenland. All of them are the ancestors of modern and late Pleistocene animals. But most of all, scientists were surprised that mastodons, close relatives of elephants, lived on the island.

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Two million years ago, mastodons lived in Greenland, relatives of elephants

In addition to animals and birds, scientists were able to detect the DNA of several species of trees, fungi and bacteria. Among them were willow, poplar and birch trees. Some of the discovered genera of animals and plants in Greenland are no longer found, while others exist to this day.

It must be said that not all ancient DNA found in Greenland is similar to the existing genetic sequences. This may indicate that they belonged to species unknown to science. The only thing scientists managed to correctly establish was the genus of all the hosts of the discovered genetic sequences.

Now we can say with confidence that Greenland was rich in mixed forests, where poplars, arborvitae and birches grew. The vegetation also included grasses and taiga shrubs. Moreover, this ecosystem has no modern analogues.

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A study of sedimentary rocks showed that many species are able to adapt to strong climate changes

How has the climate changed in Greenland?

The layer of sediments in which the researchers were able to detect ancient DNA accumulated over 20 thousand years, about 2 million years ago. The temperature on the island at that time was higher than now by 11-19 degrees Celsius.

The minimum temperature on the island did not fall below -17-10 degrees Celsius. This suggests that in the history of our planet there have already been periods of global warming. By the way, earlier we said that evidence of extreme climate change on the planet was found on the ruins of the Vikings.

According to scientists, the study showed that most species are able to evolve and adapt to highly changing temperatures. As we said above, not all species that lived in Greenland two million years ago are now extinct.

However, it takes time to adapt to a changing climate. In other words, a more important indicator for the survival of species is not even a change in average temperature, but the time during which it occurs.

Therefore, many modern species that are on the verge of extinction as a result of global warming are unlikely to be able to adapt and survive, as their ancient ancestors once did. The fact is that at present global warming is not caused by natural processes, but by human activities.

As a result, it is developing much more rapidly than it was before. Moreover, it has not yet been possible to stop it, since it was not possible to reduce carbon dioxide emissions into the atmosphere, as recently reported by scientists.

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