A shallow, salty lake in British Columbia could point to the origins of life on Earth

For centuries, scientists have been pondering questions about the origin of life on Earth. As it turns out, the answer may lie in a small, unassuming lake in the interior of British Columbia.

Located about 150 kilometers northwest of Kamloops, British Columbia, Last Chance Lake is a shallow lake filled with murky water.

A recent study from the University of Washington found that the region has the right conditions to be what scientists call the “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, which is where did we come from?” David Catling, the study’s senior author, said:

A piece of algae on top of a black, tar-like substance with salt crystals on top.
A piece of salt crust held by a researcher. Green algae can be seen in the middle, with black sediment at the bottom. (Submitted by David Catling)

Catling said Last Chance Lake supports the “little warm pond” hypothesis put forward by 19th-century scientist Charles Darwin. Darwin proposed that life on Earth could arise in shallow lakes with the right ingredients.

According to researchers, Last Chance Lake has that cocktail: It contains high levels of salt and minerals from the volcanic body it sits on — the Caribou Plateau — and a very high concentration of phosphate.

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

Although there are many phosphate-dense bodies of water on Earth, the team found that Last Chance Lake had the highest levels ever recorded through a literature survey — information that was included in the appendix to the University of Saskatchewan’s master’s thesis. 1990s.

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

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

The team visited the lake three times in different seasons, and noticed that the lake freezes in winter and dries up to form a salt flat at the end of summer, when phosphate concentrations are at their highest levels.

These phosphate-rich lakes were more common on Earth about four billion years ago, Catling says.

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

Hydrothermal vents

CBC science columnist Torah Kachur says the little warm pond theory is one of several theories trying to explain the beginnings of life on Earth.

Another common hypothesis is that life arose from high-pressure, mineral-dense hydrothermal vents found on the ocean floor.

Although lakes like Last Chance Lake don’t have the same high-pressure energy as hydrothermal vents, they have all the necessary ingredients, she says.

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

Extraterrestrial effects

Previous early life studies on British Columbia, in 2011, focused on a team of American and Canadian scientists Explore two BC lakes To study the first forms of microbe-based life, and to refine exploratory techniques and clues that may be useful in future space missions.

Catling said the findings from this study indicate that life may have formed in a similar way on other planets at some point.

He says that rock formation that leads to the development of lakes similar to Last Chance Lake is common on rocky planets.

Broadcast7:09Secrets of Last Chance Lake

Science columnist Torah Kashore explains why scientists are so fascinated by a nondescript lake in British Columbia.

Under different atmospheric conditions, when the solar system was young, he says this type of lake could form on planets like Mars or Venus.

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

“This is kind of a positive message for the origin of life.”

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