'Unimaginable' theory emerges about desolate continent
Scientists have revealed strange details of how Antarctica once looked as they search for DNA inside tiny amber fragments.
Anyone who has seen the blockbuster movie Jurassic Park would be wary of plans to extract DNA from a fragment of 90-million-year-old amber. But that’s exactly what German scientists are hoping to do with the only known grains of the substance extracted from mainland Antarctica — the Pine Island Amber.
Dr Johann Klages from the Alfred Wegener Institute told Yahoo News that despite DNA breaking down very quickly, there’s a slim chance traces could have survived because of the polar continent’s frigid conditions. For seven years, he's been studying around 40 sand-sized fragments unearthed from deep underneath Antarctica’s ice sheets, working to build a picture of the "unimaginable" landscape that once flourished there.
The grains were excreted from a tree that grew at a time when rainforests towered over Antarctica. While it may seem remarkable to have lush greenery in such cold conditions, Earth was a very different place back then, with extremely high levels of carbon dioxide in the atmosphere — 1200 to 1700 parts-per-million (ppm) compared to 400ppm today.
“A diverse temperate rainforest environment is something we cannot imagine on a latitude like this,” Klages said. The forest grew just 900 km from the South Pole, when New Zealand and Australia were still situated close to Antarctica.
“But it tells us what the what the planet is capable of doing once you go outside the human perspective. Because this all happened long before humans ever existed on planet Earth.”
What did Antarctic forests look like?
In 2020, Klages and his team have theorised about the appearance of the entire ecosystem that surrounded the amber source tree. This was done after analysing fossils of pollen, spores, and roots, which were found in sediment close to the amber.
Now they are furthering the research by analysing tiny fragments of the bark contained in the amber and searching for tiny spores that may have been preserved with more detail than the fossils.
This work has helped them build a picture of western Antarctica 90 million years ago — back then it was a swampy place with towering trees. Now they’re hoping to learn more about the specific tree the amber came from.
“This will give us more details about these forests close to the South Pole that don't have any modern analog,” Klages said.
“How did these forests survive? How was it possible that such a diverse environment was able to sustain such harsh conditions? Back then, there must have been around four months of total darkness like today.”
Excitement builds in search for 90 million-year-old DNA
If you’ve listened to a true crime podcast you’re probably familiar with the concept of touch DNA. When a criminal sits at a table or brushes past a mirror, they leave a small amount of genetic material behind. And the same rules apply to animals and insects that lived during the Cretaceous period.
The oldest known DNA was dated at 2 million years by researchers from the University of Copenhagen. Klages is working with that same team to analyse the Antarctic amber.
Although the chances of finding traces that are 90 million years old are slim, the team is hopeful the sealing of Antarctica with a giant ice sheet 15 to 20 million years ago could have preserved it. Also on their side is DNA's ability to cling to fine-grained sediments like those around the amber.
“We see a chance of maybe finding DNA. It’ll probably be highly fragmented. But it would of course be extremely exciting,” Klages said.
Earth to undergo unprecedented change
As the climate rapidly warms due to increased levels of fossil fuels in the atmosphere, the world will again undergo a change unprecedented in human history.
“It’s not only scary. As a scientist I find it rather interesting, like a gigantic experiment,” Klages said.
“Of course, climate change will not be without consequences for us. But if you look at Earth's history, we’ve always had these huge mass extinction events, especially related to climate, and for us geologists, this is nothing new.
“We see people running around saying, it's always been warm on the planet, and there's always been climate with high carbon dioxide. But never when humans were around.”
Klages believes it's a “huge challenge” for humans to grasp how dramatically the climate is likely to change in future. Most families can’t track their genetic line more than three or four generations, so our knowledge and thinking is relatively short-term.
Although humankind has lived through some climactic changes, the last million years have been relatively stable.
“Of course, we’ve seen interglacial cycles and climate changes, but nothing compared to a switch from a greenhouse to an icehouse climate or the other way around," he said.
“This is something that we’ve never experienced so far, and it wouldn’t be good for us because our bodies are not made for that.”
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Jurassic Park quote provides hope for life on Earth
By 2050 carbon dioxide concentrations are set to hit 500 parts per million and average temperatures will warm by two degrees above preindustrial averages, meaning the changes many of us will experience in our lifetimes will be extreme.
“We would need to go back to the Miocene, 14.5 to 17.5 million years ago – this was the last time when the planet had carbon dioxide concentrations and temperatures similar,” Klages said.
“This is the timeframe you need to consider when we think about the reality in such conditions. It is so far away from what we can imagine, but we have to do that when we want to consider what the future will be like.”
Life for humans will become increasingly unpleasant, particularly for those who live in countries that do not have funds to mitigate the impacts of climate change. But the changing atmospheric conditions will likely favour other organisms, which could thrive as we decline.
The most important line in Jurassic Park was arguably a warning spoken by Jeff Goldblum’s fictional character. He says, “Life will not be contained. Life breaks free, it expands to new territories and crashes through barriers painfully, maybe even dangerously… I’m simply saying that life finds a way.”
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