Scientists discover oldest known fragment of DNA in Greenland

You all know what a DNA is, isn’t it? It’s that part of a living being that contains genetic information. Recently, scientists have unearthed the oldest known fragments of DNA from the northern parts of Greenland (Kap Kobenhavn site near Peary Land) that dates back two million years ago. Preliminary examination of the samples sheds light on the ancient ecosystem of once lush green landscape that had a wide range of flora and fauna, including the extinct mastodon that is now just a barren Arctic desert. Earlier, the oldest known DNA samples belonged to the DNA of 135 species including the mammoth native to Siberia and only a million years old.  

The brand-new study has been conducted by researchers based at the University of Copenhagen and University of Cambridge and throws light on a lost past. The latest environmental DNA (eDNA) has been derived from soil samples that accompanied animal fossils of those ages and offers insight into the genetic materials of organisms as well as their habitats through analysis of their hair, waste, spit and decomposed carcases.  

Previously, studying ancient DNA was a challenge as DNA often breaks down over time. However, with advanced technology, scientists can now derive genetic information even from tiny and damaged fragments of DNA. The latest study has been published in the scientific journal Nature.  

Wondering how the samples were preserved for so long? Well, it’s because of climate change when the temperatures shifted from hot and humid desert (almost 20 degrees higher than today) to polar conditions and turning everything into permafrost. Interestingly, researchers didn’t just start unearthing the samples, it began as early as 2006.  

Okay, so the oldest DNA belongs to which species? Well, that would be a blend of Arctic plants such as birch trees, willow shrubs, firs and cedars. Animals such as geese, hares, reindeers and lemmings can also be traced. Earlier, the oldest DNA from Greenland belonged to hare and dung beetle.  

Guess what the biggest surprise was? Finding the DNA samples of mastodon that was previously only found in temperate forests of North America, far from Greenland.  

Apart from terrestrial life, scientists have also discovered information about marine life in ancient Greenland and the DNA segments were located at the mouth of a fjord. Species such as horseshoe crabs and green algae have so far been traced, both native to warmer waters. However, what continues to be a mystery is whether all these species co-existed or they turned up one after the other. But this study definitely reveals a rich biodiversity. Experts believe that further analysis will turn these DNA samples into a “genetic roadmap” to help present-day earthlings adapt to current climate change.