For decades, scientists searching for life beyond Earth have focused on one central challenge: identifying the right molecules to look for on distant planets and moons.
But new research published in Nature Astronomy suggests the answer may lie not in the molecules themselves, but in the hidden patterns that connect them.
“We’re showing that life does not only produce molecules,” said Fabian Klenner, UC Riverside assistant professor of planetary sciences and co-author of the study. “Life also produces an organizational principle that we can see by applying statistics.”
Hidden Chemical Patterns May Reveal Life
The researchers discovered that amino acids found in living systems tend to be both more varied and more evenly distributed than amino acids formed through nonbiological processes. Fatty acids showed the opposite trend, with nonliving chemical processes producing more even distributions than biological ones.
According to the team, this is the first study to show that this underlying signature of life can be detected through statistics alone, without relying on any single specialized instrument. That means the approach could potentially work using data already being collected by current and future space missions.
The findings arrive at a time when planetary exploration is advancing rapidly. Missions studying Mars, Europa, Enceladus, and other worlds are producing increasingly detailed measurements of organic chemistry. However, interpreting those chemical signals remains a major challenge.
Many molecules linked to life on Earth, including amino acids and fatty acids, can also form naturally without biology. Scientists have found them in meteorites and created them in laboratory experiments designed to mimic space environments. Because of that, simply detecting these compounds is not considered strong enough evidence to confirm life.
“Astrobiology is fundamentally a forensic science,” said Gideon Yoffe, postdoctoral researcher at the Weizmann Institute of Science in Israel and first author of the study. “We’re trying to infer processes from incomplete clues, often with very limited data collected by missions that are extraordinarily expensive and infrequent.”
Borrowing a Tool From Ecology
To tackle the problem, the researchers adapted a statistical method commonly used in ecology. Ecologists measure biodiversity using two main concepts: richness, which describes how many different species are present, and evenness, which measures how uniformly they are distributed.
Yoffe first encountered this framework during doctoral studies in statistics and data science, where diversity metrics were used to uncover patterns in complicated datasets, including research involving ancient human cultures.
The team then applied the same statistical logic to chemistry associated with possible extraterrestrial life.
Using roughly 100 existing datasets, the scientists examined amino acids and fatty acids from microbes, soils, fossils, meteorites, asteroids, and synthetic laboratory samples. Again and again, biological materials displayed distinct organizational patterns that separated them from nonliving chemistry.
Fossils Still Carried Signs of Ancient Life
One of the most surprising findings was how effective the method remained despite its simplicity.
By analyzing samples through this statistical lens, the researchers could reliably distinguish biological samples from abiotic ones. They also observed that biological materials formed a continuum ranging from well preserved to heavily degraded.
“That was genuinely surprising,” Klenner said. “The method captured not only the distinction between life and nonlife, but also degrees of preservation and alteration.”
Even samples that had undergone significant degradation still preserved traces of this organizational structure. Fossilized dinosaur eggshells included in the study, for example, continued to show detectable statistical patterns connected to ancient biological activity.
A New Tool for Future Space Missions
The researchers caution that no single technique will be enough to prove the existence of extraterrestrial life.
“Any future claim of having found life would require multiple independent lines of evidence, interpreted within the geological and chemical context of a planetary environment,” Klenner said.
Even so, the team believes this framework could become a valuable addition to future planetary missions searching for evidence of life beyond Earth.
“Our approach is one more way to assess whether life may have been there,” Klenner said. “And if different techniques all point in the same direction, then that becomes very powerful.”