The oldest DNA discovered so far is approximately 2 million years old.
While DNA is constantly being replicated and passed on, the survival of ancient DNA is limited by degradation processes. Researchers are continually pushing the boundaries of what's possible in terms of retrieving and sequencing increasingly old genetic material. Here's a breakdown of significant milestones:
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Mammoth Molars (Around 1 Million Years Old): Previously, the oldest DNA sequenced from a physical specimen was obtained from mammoth molars found in Siberia. This groundbreaking research pushed the limit of recoverable DNA to around a million years.
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Sediment DNA from Greenland (Around 2 Million Years Old): In 2022, even older genetic material was recovered from sediments in Greenland. This DNA is estimated to be approximately two million years old, making it the current record holder for the oldest discovered DNA. This discovery significantly expands our understanding of ancient ecosystems and the evolution of life on Earth.
The preservation of DNA is highly dependent on environmental conditions. Cold, dry, and stable environments are more conducive to long-term DNA survival. This explains why the oldest DNA has been found in regions like Siberia and Greenland. Factors like temperature, humidity, and exposure to UV radiation can accelerate DNA degradation. Therefore, finding and analyzing ancient DNA remains a challenging but rewarding scientific endeavor.
