Scientists Discover New Clues About the Origin of Complex Life
Research suggests that all complex life forms, including humans, plants, and animals, trace their roots to a common Asgard archaean ancestor
This discovery aids in understanding the evolutionary step from microbes to eukaryotes and reveals that the Asgard archaea, evolving over 2 billion years ago, appear to be the progenitors of eukaryotic organisms.
The mythological Norse god Thor hails from the celestial city of Asgard, and according to revolutionary research published in the scientific journal, Nature, he’s not the only Asgardian.
This new research suggests that we humans — along with eagles, starfish, daisies, and every complex organism on Earth — are, in a sense, Asgardians.
The research team at The University of Texas at Austin, along with collaborators from different institutions, conducted a genomic analysis of several hundreds of microorganisms known as archaea.
Their findings revealed that eukaryotes – complex life forms with nuclei in their cells, including all flora, fauna, insects, and fungi across the globe – can trace their origins back to a common Asgard archaean ancestor.
That means eukaryotes are, in the parlance of evolutionary biologists, a “well-nested clade” within Asgard archaea, similar to how birds are one of several groups within a larger group called dinosaurs, sharing a common ancestor.
The team has found that all eukaryotes share a common ancestor among the Asgards.
Image: University of Texas at Austin
No fossils of eukaryotes have been found from farther back than about 2 billion years ago, suggesting that before that, only various types of microbes existed.
“So, what events led microbes to evolve into eukaryotes?” said Brett Baker, UT Austin associate professor of integrative biology and marine science. “That’s a big question. Having this common ancestor is a big step in understanding that.”
Led by Thijs Ettema of Wageningen University in the Netherlands, the research team identified the closest microbial relative to all complex life forms on the tree of life as a newly described order called the Hodarchaeales (or Hods for short).
The Hods, found in marine sediments, are one of several subgroups within the larger group of Asgard archaea.
The Asgard archaea evolved more than 2 billion years ago, and their descendants are still living. Some have been discovered in deep-sea sediments and hot springs around the world, but so far only two strains have been successfully grown in the lab.
To identify them, scientists collect their genetic material from the environment and then piece together their genomes. Based on genetic similarities with other organisms that can be grown in the lab and studied, the scientists can infer metabolism and other features of the Asgards.
“Imagine a time machine, not to explore the realms of dinosaurs or ancient civilizations, but to journey deep into the potential metabolic reactions that could have sparked the dawn of complex life,” said Valerie De Anda, a researcher in Baker’s lab. “Instead of fossils or ancient artifacts, we look at the genetic blueprints of modern microbes to reconstruct their past.”
The researchers expanded the known Asgard genomic diversity, adding more than 50 undescribed Asgard genomes as input for their modeling. Their analysis indicates that the ancestor of all modern Asgards appears to have been living in hot environments, consuming CO2 and chemicals to live.
Meanwhile, Hods, which are more closely related to eukaryotes, are metabolically more similar to us, eating carbon and living in cooler environments.
“This is really exciting because we are looking for the first time at the molecular blueprints of the ancestor that gave rise to the first eukaryotic cells,” De Anda said.
In Norse mythology, Hod (also spelled Höd, Höðr or Hoder) is a god, the blind son of Odin and Frigg, who is tricked into killing his own brother Baldr.
“I keep joking in my talks that ‘We are all Asgardian’,” Baker said. “Now that’s probably going to be on my tombstone.”
Asgard archaea tree. Credit: University of Texas at Austin
“To me, the most exciting thing is that we’re starting to see the transition from what biologists think is an archaeon to this organism Hodarchaeales that is more like a eukaryote,” Baker explained. “Another way to put it is that these Hods are our sister group in the archaeal world.”
Baker said it makes sense that of all the archaea, the Asgards are the ones that spawned eukaryotes. Like eukaryotes, members of the Asgard archaea have many genes with multiple copies in their genomes.
In eukaryotes, when genes became duplicated, the new copies often took on new functions, giving organisms new abilities. It was one of the big drivers of evolution.
“We don’t know, in these Asgards specifically, what the gene duplications led to,” Baker said. “But we know in eukaryotes that gene duplications led to new functions and an increasing of cellular complexity. So, we think that that’s one of the ways that Asgards led to the innovations that define eukaryotes.”
Scientists studying archaea have found many proteins that were once thought to be exclusive to eukaryotes. Baker said that raises the question: What functions are these eukaryotic proteins serving in the archaea?
“I think studying these simpler forms of life and their eukaryotic characteristics is going to tell us a lot about ourselves,” Baker said.
Reference
“Inference and reconstruction of the heimdallarchaeial ancestry of eukaryotes” by Laura Eme, Daniel Tamarit, Eva F. Caceres, Courtney W. Stairs, Valerie De Anda, Max E. Schön, Kiley W. Seitz, Nina Dombrowski, William H. Lewis, Felix Homa, Jimmy H. Saw, Jonathan Lombard, Takuro Nunoura, Wen-Jun Li, Zheng-Shuang Hua, Lin-Xing Chen, Jillian F. Banfield, Emily St John, Anna-Louise Reysenbach, Matthew B. Stott, Andreas Schramm, Kasper U. Kjeldsen, Andreas P. Teske, Brett J. Baker and Thijs J. G. Ettema, 14 June 2023, Nature.
DOI: 10.1038/s41586-023-06186-2
Support for this research was provided by the Origin of Eukaryotes program at the Moore and Simons Foundations, U.S. National Science Foundation, the Wellcome Trust Foundation, the European Research Council, the Swedish Research Council, the Dutch Research Council, the National Natural Science Foundation of China, the Wenner-Gren Foundation, the Science for Life Laboratory (Sweden) and the European Commission’s Marie Skłodowska-Curie Actions.
Other authors from UT Austin are Kiley W. Seitz and Nina Dombrowski. In addition to Ettema, authors from other institutions are Laura Eme, Daniel Tamarit, Eva Caceres, Courtney Stairs, Max Schön, William Lewis, Felix Homa, Jimmy Saw, Jonathan Lombard, Takuro Nunoura, Wen-Jun Li, Zheng-Shuang Hua, Lin-Xing Chen, Jillian Banfield, Emily St. John, Anna-Louise Reysenbach, Matthew Stott, Andreas Schramm, Kasper Kjeldsen and Andreas Teske.
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Tom
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It’s a shame they won’t find any intelligent life on earth…especially if they look in the mirror.
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Howdy
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Asgard? Why not Mt Olympus, or even Heaven? it’s the same thing, different people.
All life came from a mythical norse idea eh- How is mythology scientific, or am I missing something?
The three pronged tree above is even called the tree of life in places. Sorry but too late, This is the tree of life:
https://www.learnreligions.com/divine-names-kabbalah-tree-of-life-124389
Malkuth is the Earth.
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Wisenox
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Really?
Let’s go a little further than the article writer seems capable of doing.
“Loki, the mischief-maker, upon finding out about Baldr’s one weakness, made a spear from mistletoe, and helped Höðr shoot it at Baldr.”
Its another story of the sun. What we’re looking at is the Pale Horse, or at least 1/2 of it.
Loki is the “trickster”, or the “hitch” of the plow. He is Vulpecula in the sky, and he sits next to Cygnus, which is the “beam” of the plow. Underneath Loki/Vulpcula is the spear, Sagitta, which is also the “Spear of Destiny”. This Catasterism is known as Bellepheron and “Death” (Equuleus, Sagitta, Vulpecula).
This is also the Swine from ancient Sumeria, and is why pigs are associated with horror and death. He eats the flesh of the fruit, or blood. He is also known as the bat, flying mammal, and leather flapper. He has been represented by people such as the plague doctors, who were the ones spreading pestilence with the plague.
The other half of the Pale Horse, Hades, is a Catasterism of Lacerta and Cygnus. In other words, he is the crucifix. Get it? Lance and crucifix, sacrifice of Christ?
In ancient Sumeria, Hades is known as the “King of the Dead” and is a winged panther. He eats the flesh of the body, and he sits outside the UN today. Look up panther statue at UN.
In ancient Egypt the swine and the panther were united the the Catasterism of Seth and is why Seth is called the “Set Aninal” (beasts are made from many parts).
Its no coincidence that you see bat wings associated with the Death depictions either. The word bat describes the manner of death and a bat is both a leather flapper and flying mammal that eats the fruit or blood of its prey. Not a surprise that covid comes from bats, just as the plague came from plague doctors. Or, that they commemorated the bat on the 2020 US quarter.
There’s a term for this, I believe its called “In Plain Sight”.
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Wisenox
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To expand on my post, “Life” comes from this because of who “Life” is.
The events I described above were events at the end of the age. Every new age begins with a “Dawn”. The dawn is twilight, which is “Adam”, or “Man”. This is also the side of “Life”. Thus, life begins from Asgard, or whatever comparative mythology you wish to use.
Twilight is Enki from ancient Sumeria and Lucifer from the Bible. He is also Adam and Eve, or, morning and evening, as he is the twilight. This is also why Eve comes from Adam.
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