- [Narrator] Scientists announced they sequenced the oldest DNA to date, 2 million year old DNA found in Greenland, revealing an ancient ecosystem, unlike anything existing today. - Finding DNA in the deep
time context is amazing. It's really important for how
this field is gonna advance. - It's really the most
remarkable new thing since I've been working in this area. - [Narrator] The movie Jurassic Park made the idea of
recovering old DNA popular. (dinosaur roaring) But successfully sequencing
really ancient DNA has proved elusive. - The irony is that in 2005, I did a review paper and I said, well, it's not possible
that DNA can survive more than 1 million years, right? - [Narrator] The latest
work by Eske Willerslev and his team extends the
record of ancient DNA by about another million years. To find the DNA, researchers drilled in the Kap Kobenhavn
Formation in Greenland to collect soil samples. They found evidence of
ancient living things, including horseshoe crabs,
caribou, and even mastadon, using DNA found in soil. - Every single cell contains DNA. If a mastodon urinates or
puts feces on the ground, you know, it's DNA. You can't identify it
after you know some time, but the DNA will survive. - [Narrator] It's likely
that the ancient DNA was uniquely preserved by a combination of the
cold and some minerals in the 2 million year old sediment. - DNA is electrically charged. And many sediment particles
are also electrically charged. So certain sediment particles,
such as clay will bind DNA. I mean, the DNA will
basically stick to it. - The binding, basically protects the DNA from the enzymes that
would otherwise chop it up. - [Narrator] That bond may
have kept that DNA intact for far longer than scientists, including Willerslev,
had thought possible. But to retrieve the DNA from the soil and separate it from everything else in it required state of the art technology and techniques developed over
many years of trial and error. - I mean, I don't even know
how to describe it, right? I mean, you have been sitting, working on something for, (chuckles) for 15 years that doesn't work. And suddenly there's a breakthrough. It's like, you said, oh my God, right? - Sounds very boring to
many people at first, but this is the fundamental
thing that changes everything. And suddenly you can have samples that you thought had no DNA at all. It turns out they did
have DNA but it's stuck and all you're doing is releasing it. - [Narrator] The next challenge
was to compare the DNA to vast libraries of all other known DNA to identify close relatives. The plants, animals they found
in this ancient ecosystem do not exist together today. - So, for example, we
find a horseshoe crab, which is a crab that is found, way, way to the south today. And also suggests that
the ocean at that time was way warmer than what we see today. - [Narrator] Unlike the polar
desert that exists here today, this forest ecosystem could
have been considerably warmer. But like Greenland today,
existed in extreme seasonality, months of summer sun and complete darkness
in the winter months. - I think that's really stunning. Still stunning to me to think of how warm it is. And that you have life over time that has adapted to the
extreme seasonality. - [Narrator] Understanding the lineage of these ancient living things could help researchers understand how those that exist today evolved, and how they might adapt
to a changing climate. - If it works, it's gonna
change everything for us. In terms of thinking about
how ecosystems respond to climate change - All of this is like building blocks. You get one building block,
you don't have a structure, you get two, you still
don't have a structure. You have 10, and you can
start building something. (uplifting music)
