Dead – yes, dead – tardigrade found beneath Antarctica

A completely unexpected discovery beneath the ice.

  • Scientists find remains of a tardigrade and crustaceans in a deep, frozen Antarctic lake.
  • The creatures' origin is unknown, and further study is ongoing.
  • Biology speaks up about Antarctica's history.

So it turns out our favorite real-world superheroes, tardigrades, aren't completely indestructible. But even in death, they continue to amaze. Scientists boring a hole one kilometer beneath the ice deep within a buried Antarctic lake recently got a bit of a shock. They came across the remains of once-living creatures, some ancient crustaceans, and — you guessed it — a water bear. How all of the creatures got there remains unclear.

The discovery was "completely unexpected," micropaleontologist David Harwood tells Nature. The drilling was done under the auspices of the SALSA (Subglacial Antarctic Lakes Scientific Access) project. Glaciologist Slawek Tulaczyk, who's not involved with SALSA, says, "This is really cool. It's definitely surprising."

Welcome to Subglacial Lake Mercer

The scientists were drilling in Subglacial Lake Mercer, a frozen body of water undisturbed for millennia. SALSA's is the first direct sampling of its contents. Prior to the drilling, it had only been examined with ice-penetrating radar and some other indirect detection devices.

Boring details

SALSA drilled down a kilometer into the ice above Lake Mercer using a hot-water drill . At its maximum width, the hole was just 60 centimeters across.

On December 30, the team retrieved a temperature sensor from the frozen lake and noticed some gray-brown mud stuck to the bottom of it. Looking at the mud under a microscope, Harwood saw the glassy remains of photosynthetic diatoms, which he expected, but also a shrimp-like crustacean shell with its legs still intact. And then another, even better-preserved one.

To double-check, the team cleaned off their sensor and sent it down for more mud. This time, more crustacean shells and some other things that looked a bit like worms appeared under the microscope. On January 8, at a National Science Foundation base 900 kilometers away, animal ecologist named Byron Adams had a look. He confirmed the crustaceans, found the tardigrade, and identified the worm-like organisms as being thread-like plants or fungi. He'd seen all three types of creatures previously in the glacier-free Dry Valleys of Antarctica, as well as in the Transantarctic Mountains.

Where the organisms were found, but why?

The animals could have come from other places, such as the ocean. Between five and ten thousand years ago, the Antarctic ice sheet became thinner for a while, and this could have allowed seawater to make its way beneath floating ice, carrying organisms along with it that eventually became trapped beneath the ice sheet when it returned to its normal thickness.

The water sampled from Lake Mercer has enough oxygen to sustain life, and is packed with bacteria, over 10,000 cells per millimeter. Harwood wonders if larger animals could have survived feeding on them, though the majority of biologists don't think it's likely to have been a substantial enough food source.

Adams suspects the creatures actually lived in the Transantarctic Mountains and were then transported after dying down to Lake Mercer. He says they seem too recent to have been neighbors of the millions-of-years-old diatoms. "What was sort of stunning about the stuff from Lake Mercer," Adams tells Nature, "is it's not super, super-old. They've not been dead that long." The eight-legged tardigrade from Lake Mercer resembles those found in damp soil, reinforcing Adam's conclusion.

Back to the lab

The next steps for these intriguing remains is an attempt at determine their age using radiocarbon dating. In addition, researchers will try and sequence DNA scraps from them to learn if they're of marine or freshwater species. Finally, scientists will perform chemical analyses of carbon the remains contain to see if a determination can be made as to whether the animals spent their days in sunlight or in the dark, far beneath the Antarctic.

Should you defend the free speech rights of neo-Nazis?

Former president of the ACLU Nadine Strossen discusses whether our society should always defend free speech rights, even for groups who would oppose such rights.

Sponsored by Charles Koch Foundation
  • Former ACLU president Nadine Strossen understands that protecting free speech rights isn't always a straightforward proposition.
  • In this video, Strossen describes the reasoning behind why the ACLU defended the free speech rights of neo-Nazis in Skokie, Illinois, 1977.
  • The opinions expressed in this video do not necessarily reflect the views of the Charles Koch Foundation, which encourages the expression of diverse viewpoints within a culture of civil discourse and mutual respect.
Keep reading Show less

It’s just a sheet of glass. With AI.

A new paradigm for machine vision has just been demonstrated.

Image source: aleknext/Shutterstock
Technology & Innovation
  • Scientists have invented a way for a sheet of glass to perform neural computing.
  • The glass uses light patterns to identify images without a computer or power.
  • It's image recognition at the speed of light.
Keep reading Show less

New alternative to Trump's wall would create jobs, renewable energy, and increase border security

A consortium of scientists and engineers have proposed that the U.S. and Mexico build a series of guarded solar, wind, natural gas and desalination facilities along the entirety of the border.

Credit: Purdue University photo/Jorge Castillo Quiñones
Politics & Current Affairs
  • The proposal was recently presented to several U.S. members of Congress.
  • The plan still calls for border security, considering all of the facilities along the border would be guarded and connected by physical barriers.
  • It's undoubtedly an expensive and complicated proposal, but the team argues that border regions are ideal spots for wind and solar energy, and that they could use the jobs and fresh water the energy park would create.
Keep reading Show less

Elon Musk’s Neuralink unveils device to connect your brain to a smartphone

"A monkey has been able to control a computer with its brain," Musk said, referring to tests of the device.

Neuralink
Technology & Innovation
  • Neuralink seeks to build a brain-machine interface that would connect human brains with computers.
  • No tests have been performed in humans, but the company hopes to obtain FDA approval and begin human trials in 2020.
  • Musk said the technology essentially provides humans the option of "merging with AI."
Keep reading Show less