You can thank these ancient microbes for your immune system
Researchers use electron microscopes to study archaea, unicellular organisms found around the world. RichLegg/Getty Images hide caption
Researchers use electron microscopes to study archaea, unicellular organisms found around the world.
RichLegg/Getty ImagesA growing body of research suggests humans owe an evolutionary debt to Asgard archaea, a group of single-celled organisms discovered in hydrothermal vents in 2015.
"The first one was found in this hydrothermal vent in the North Atlantic called Loki's Castle," said Brett Baker, a marine biologist at the University of Texas at Austin.
After the discovery of Lokiarchaeota, subsequent groups were named after Thor, Odin and Heimdall.
This special superphylum of organisms — known as Asgardarchaeota — are found hot springs, aquifers, freshwater and even saltwater environments around the world.
They're also providing fresh insight into the origins of life.
In the last decade, genetic sequencing revealed that Asgard archaea contain proteins more commonly found in eukaryotes, the group of organisms that includes animals, plants and fungi. Though 2 billion years of evolution has passed, Baker says this suggests that the eukaryotic branch of life emerged from Asgardian archaea.
"I literally went running into my grad students office and I said, 'Oh my God, we have something very big,'" Baker recalls.
Newer research continues to bear this out.
Microbiologist Pedro Leão, an assistant professor of microbiology at Radboud University in the Netherlands, has determined that two key proteins of humans' innate immune system — viperin and argonaute proteins — may have originated with Asgards. Those findings were published in a paper in Nature Communications in July 2024.
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This episode was produced by Hannah Chinn and edited by our showrunner, Rebecca Ramirez. Tyler Jones checked the facts and Jimmy Keeley was the audio engineer.