“NASA’s ENIGMA (Evolution of Nanomachines In Geospheres and Microbial Ancestors) research team,” evolutionary biologist Paul Falkowski told The Daily Galaxy, “is focused on answering a single, compelling question in astrobiology: How did proteins evolve to become the predominant catalysts of life on Earth?
“In science fiction, there is a lot of effort put into searching for signs of life like plants, animals and organisms that look like us. But there is a higher probability that alien life will be at the microscopic level,” says Rutgers University geochemist, Nathan Yee, co-investigator at the NASA-funded ENIGMA project that’s researching how proteins, “sophisticated nanomachines,” evolved to create life on earth. “That fact is so much more interesting when you consider what the earliest lifeforms on Earth were capable of doing.”
There is a higher probability that alien life will be at the microscopic level”
Probing for Microbial Dark Matter
“The ENIGMA project is a unique collaboration joining mineralogists, geochemists, biochemists, and bioinformaticists with the unified aim of understanding what the earliest energy-transforming proteins, or oxidoreductases, may have looked like, the metals they interacted with, and how those interactions have shaped the geochemical conditions on Earth,” explained Adrienne Hoarfrost in an email to The Daily Galaxy. Hoarfrost is a NASA Fellow with the Bromberg Lab, NASA Ames Research Center, working with the ENIGMA team to investigate the relationship between microbes and their environment, on our modern Earth, throughout Earth’s history, and in potential environments on other planets.
“Even the earliest lifeforms had a profound effect on the mineralogy and geochemistry on Earth,” Hoarfrost explains, “which we can see in the mineralogical rock record and in the diversity of protein-metal interactions over evolutionary time, My work creating LookingGlass, a deep learning model of the ‘universal language of life’, helped the ENIGMA team to understand the fundamental features of these oxidoreductases, and to mine environmental microbial communities for novel ‘microbial dark matter’ oxidoreductases that may help us to fill in the gaps in the protein evolutionary tree.”
Life is Electric
The ENIGMA project (Evolution of Nanomachines In Geospheres and Microbial Ancestors) explores the catalysis of electron transfer reactions by prebiotic peptides to microbial ancestral enzymes to modern nanomachines, integrated over four and a half billion years of Earth’s changing geosphere. Currently, very little is known about the origin of these proteins on Earth or their evolution in early microbial life.
All things eat and breathe, and when you remove oxygen, like on ancient-Earth or Mars atmospheres, there are microbes that have figured out ways to breathe other things, like iron found inside of rocks,” Yee said.
NASA wanted someone with expertise about microbes interacting with minerals and the biosignatures that ancient Earth microbes left behind in rocks after they died and went extinct, which happens to be my area of expertise, Yee added.
Searching for building blocks of life on other planets and moons
“Everywhere there is liquid water on Earth, we’ve found microbial life. We are smart enough to know that if a world has oceans, then we should look there for alien microbes. Europa, which is one of Jupiter’s moons, has what appears to be global oceans under sheets of ice. Saturn’s moon Enceladus has geysers and hot springs spewing from its south pole,” Yee said, explaining that in our search to find extraterrestrial life, the focus should be not on planets, but rather on moons in our galaxy where there’s evidence of water.
“That points to the possibility of volcanoes and hydrothermal vents, which on Earth harbor ancient life forms and may have contributed to the origin of life here. Now, do I think there’s going to be a whale on these moons? Likely not, but it is possible that alien microbes have evolved and continue to live there,” Yee concluded.
Image credit: There is something hauntingly biological about this ESA image of Jupiter’s moon, Europa, shown at the top of the page. The image, sent back by NASA’s Galileo spacecraft shows the moon is scarred by deep red gashes crisscrossing the icy world. They are actually cracks and ridges marking weak lines within the moon’s ice crust, emphasized and exacerbated by the swelling and falling of tides due to Jupiter’s gravitational pull. Some of these ridges are thousands of kilometers long. The startling color is due to contaminating minerals rising from beneath the icy crust, possibly salts from the underground ocean.
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