The study, led by Kevin Webster, Associate Research Scientist at the Planetary Science Institute, and co-authored by Jay Lennon of Indiana University, delves into the role of dormancy as a critical survival mechanism. Dormancy, a reversible state that organisms use to protect themselves during unfavorable conditions, may have been a pivotal factor not only in life's persistence but also in its very origin.

"I'm really interested in questions relating to the origin of life," Webster explained. "My collaborator, Jay Lennon, is really interested in dormancy. We were talking one day, and he asked if I thought dormancy was older than life. And I said, I'm almost certain it is. That's what led to this paper."

Dormancy allows organisms to mitigate environmental risks by entering a protected state and resuming activity when conditions improve. Webster highlighted its significance, noting, "If you're active, but there's no food because the river is drying up for instance, you're going to die. But if you're able to withstand those really dry conditions while dormant, then you can return to activity as soon as there's water again and live to pass on your genetic information."

Webster and Lennon's analysis of the fossil record and evolutionary history revealed that dormancy has been a survival strategy across diverse organisms throughout Earth's history. The authors noted, "By decreasing rates of mortality under suboptimal conditions, dormancy would reduce the probability of local and global extinction events. Also, dormancy creates a 'seed bank' of inactive individuals," preserving life through Earth's tumultuous early years.

The research goes a step further by suggesting that even before life began, the chemical precursors to life exhibited dormancy-like traits. These molecules likely alternated between active and dormant states, adapting to environmental fluctuations such as temperature changes or molecular availability. For example, DNA - a molecule central to life - demonstrates such behavior by separating and recombining its strands in response to temperature changes or wrapping itself around proteins for protection until favorable conditions arise.

"We make the argument that these molecules can do these things in biological settings, and that on the early Earth we might have gotten some of this behavior occurring prior to the origin of life," Webster said. Future research will aim to model how dormancy impacts the stability of chemical reaction networks in prebiotic environments subject to environmental changes.

Dormancy likely also influenced the spread of life across the planet. If life originated in isolated environments like inland hot springs, dormancy could have facilitated its dispersal beyond these confined spaces. In contrast, if life arose in the vast ocean, dormancy might not have been as critical.

Understanding how life originated, adapted, and spread on Earth offers valuable insights into how life might emerge on other planets. "How does life transition from this purely non-living state to one that is eventually alive? I'm fascinated by that question, because it can also inform the search for life on distant worlds," Webster said. "It can tell us something about the processes that a planet needs to go through for life to arise and what to look for once it does."

Research Report:Dormancy in the origin, evolution and persistence of life on Earth

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