Shallow, salty lake in British Columbia could reveal origin of life on Earth

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Scientists have pondered questions about the origins of life on Earth for centuries. It turns out the answer may lie in a small, unassuming lake in the interior of British Columbia.

Last Chance Lake, located about 150 kilometers northwest of Kamloops, British Columbia, is shallow and filled with murky water.

A recent study from the University of Washington found that this country has the ideal conditions to become what scientists call a “cradle of life,” a place where life could have spontaneously emerged billions of years ago. .

“We’re trying to answer one of the biggest unanswered questions in science: Where did we come from?” said the study’s lead author, David Catling.

A piece of seaweed on top of a black tar-like substance with salt crystals on top.
A piece of salt crust is held by one of the researchers. Green algae is visible in the middle, with black sediment at the bottom. (Submitted by David Catling)

Catling said Last Chance Lake supports 19th century scientist Charles Darwin’s “little warm pond” hypothesis. Darwin proposed that life on Earth could have emerged in shallow lakes with the right ingredients.

According to researchers, Last Chance Lake contains some key elements of this cocktail: it contains high levels of salt, minerals from the volcanic plain on which it sits – the Cariboo Plateau – and a very high concentration of phosphate.

For life to form, Catling says phosphate concentrations must be 100 to a million times higher than levels normally found in bodies of water on Earth.

Although there are several phosphate-rich bodies of water on Earth, the team discovered that Last Chance Lake had the highest levels ever recorded through a literature review – information hidden in the appendix of a master’s thesis from the University of Saskatchewan in the 1990s.

“It was … a little bit of luck and a little bit of perseverance that allowed us to identify this,” Catling said. “We thought it was very convenient because we can drive there from Seattle.”

Three people are shown walking on a salt flat.
Study researchers walk on Last Chance Lake in September 2022. Most of the lake’s water evaporates during the summer, forming a salt flat. (Submitted by Zack Cohen)

The team visited the lake three times in different seasons, noting that the lake freezes in winter and dries up to form a salt pan in late summer, when phosphate concentrations are highest.

Catling says these phosphate-rich lakes would have been more common on Earth about four billion years ago.

“Everything seemed to fall into place,” Catling said. “What we thought was happening was happening.”

Hydrothermal vents

CBC science columnist Torah Kachur says the warm pond theory is one of many that attempt to explain the beginnings of life on Earth.

Another popular hypothesis is that life originated from high-pressure, mineral-rich hydrothermal vents located on the ocean floor.

She says that while lakes like Last Chance Lake don’t have the same high-pressure energy as a hydrothermal vent, they have all the necessary ingredients.

“When Darwin suggests something – he was right about a lot of things – we add it to the list of places we need to investigate further,” Kachur said.

Extraterrestrial implications

Previous early childhood studies have also focused on British Columbia. In 2011, a team of American and Canadian scientists explored two BC lakes to study early forms of microbial life, refining exploration techniques and clues that could be useful in future space missions.

Catling said the results of this study suggest that life may have formed in the same way on other planets at some point.

Rock formations that lead to the development of lakes similar to Last Chance Lake are common on rocky planets, he says.

Diffusion7:09 a.m.The mysteries of Last Chance Lake

Science columnist Torah Kachur explains why a nondescript lake in British Columbia fascinates scientists.

Under different atmospheric conditions, when the solar system was young, this type of lakes could have formed on planets like Mars or Venus.

“The conditions under which this happens may not be that rare. It may not be such a miracle. It’s just something that happens naturally in the environment,” Catling said.

“It’s a kind of positive message about the origin of life.”

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