Have you ever wondered how old the earth is? Well, this is something we have all pondered upon but there seems to be no definite answer. Scientists have now moved closer to unveiling the age of the earth as well as its inhabitants. Scientists have discovered the oldest known DNA in Greenland, dating back two million years ago.
The land that is today filled with permafrost, was once a lush field with all types of plants and species. DNA has established that Greenland was not always cold or bare as it is today. Some of the animals that roamed the region included mastodons.
“The study opens the door into a past that has basically been lost,” said Kurt Kjær, a geologist and glacier expert at the University of Copenhagen.
Studying the age of the world has always been challenging due to the lack of sufficient DNA material. In this study, the researchers used environmental DNA (eDNA), which is obtained from soil samples made up of the genetic material of organisms that lived at that time. For instance, hair follicles, saliva and waste that fall to the ground can be preserved and make up the DNA.
The only problem with studying eDNA is that the genetic components degrade over time. Scientists are only left with small fragments to work with. Thanks to the latest technology in DNA, scientists were able to get more information out of small fragments of DNA.
According to Kjær, the sediments studied were obtained from Kap København near the northern region of Greenland. Today, the region is a polar desert, but millions of years ago it was a green landscape. The region underwent a period of intense climate change that sent temperatures down.
At the time when the DNA was deposited, temperatures are estimated to have been 20 to 34 degrees Fahrenheit higher than the current temperature in the region today.
The region grew some modern plants such as birch trees, willow shrubs and cedars. The DNA also showed traces of animals including hares, geese and reindeers, among others.
The fact that the DNA of these animals and trees were well preserved can be attributed to the permafrost. If DNA is frozen, it can stay in the ground much longer than when it is exposed to weather patterns. With melting permafrost, such DNA and other living organisms are bound to be exposed.
Via ABC News
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