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.
However, a new study has been published natural astronomy It suggests that the answer may not lie in the molecules themselves, but in the hidden patterns that connect them.
“We’re showing that life is more than just producing molecules,” said Fabian Krenner, assistant professor of planetary science at the University of California, Riverside, and co-author of the study. “Life also produces organizational principles that can be understood by applying statistics.”
Hidden chemical patterns may reveal life
Researchers have found that amino acids found in biological systems tend to be more diverse and more evenly distributed than those formed by non-biological processes. Fatty acids showed the opposite trend, with abiotic chemical processes producing a more uniform distribution than biological processes.
The research team says this is the first study to show that this underlying sign of life can be detected using statistics alone, without relying on a single specialized piece of equipment. That means the approach could work using data already collected on current and future space missions.
The discovery arrives at a time when planetary exploration is rapidly advancing. Missions studying Mars, Europa, Enceladus, and other worlds are yielding increasingly detailed measurements of organic chemistry. However, interpreting these chemical signals remains a major challenge.
Many molecules involved in life on Earth, such as amino acids and fatty acids, are also formed naturally without biology. Scientists discovered them in meteorites and created them in a laboratory designed to mimic the space environment. Therefore, detecting these compounds alone is not considered strong enough evidence to confirm life.
“Astrobiology is basically forensic science,” said Gideon Yoffe, a postdoctoral fellow at the Weizmann Institute of Science in Israel and lead author of the study. “We are trying to infer processes from incomplete clues, often using very limited data collected on very expensive and infrequent missions.”
Borrow tools from ecology
To address this issue, the researchers employed statistical methods commonly used in ecology. Ecologists measure biodiversity using two main concepts. One is richness, which measures how many different species are present, and the other is evenness, which measures how evenly they are distributed.
Yoffe first encountered the framework during his doctoral research in statistics and data science, where diversity metrics were used to uncover patterns in complex datasets, such as studies of ancient human cultures.
The team then applied the same statistical logic to the chemistry associated with the possibility of extraterrestrial life.
Using about 100 existing datasets, the scientists examined amino acids and fatty acids from microorganisms, soil, fossils, meteorites, asteroids, and synthetic laboratory samples. Biological materials have, time and again, exhibited distinct tissue patterns that distinguish them from non-biological materials.
Traces of ancient life still remain in fossils
One of the most surprising discoveries was how effective this method was despite its simplicity.
By analyzing samples through this statistical lens, researchers were able to reliably distinguish between biological and abiotic samples. They also observed that biological materials form a continuum from well-preserved to severely degraded.
“That was a real surprise,” Krenner said. “This method not only captured the distinction between living and nonliving things, but also the degree of conservation and modification.”
Even in heavily degraded samples, traces of this tissue structure still remain. For example, fossilized dinosaur eggshells included in the study continued to show detectable statistical patterns associated with ancient biological activity.
New tools for future space missions
Researchers warn that no single technique is enough to prove the existence of extraterrestrial life.
“In the future, claiming that life has been discovered will require multiple independent lines of evidence, interpreted within the geological and chemical context of the planetary environment,” Klenner said.
Still, the team believes the framework could be a valuable addition to future planetary missions searching for evidence of extraterrestrial life.
“Our approach is another way to assess whether life could have existed there,” Krenner said. “And when all the different techniques are pointing in the same direction, it becomes very powerful.”
