If you think the origins of life were a neat, straightforward process—think again. Scientists have spent decades squabbling over how the first primitive cells formed, with competing theories ranging from deep-sea hydrothermal vents to meteorite-delivered ingredients. One particularly interesting idea is that life’s precursors weren’t wrapped up in neat lipid membranes but rather existed as messy, membraneless polyester microdroplets. And according to new research, these protocells could have popped up in far more places on early Earth than we ever suspected. The findings for which were published recently in ACS Bio & Med Chem Au, providing new insights into the widespread formation of polyester protocells under diverse prebiotic conditions.

The Polyester Problem (That Turns Out Not to Be a Problem at All)

Here’s the basic setup: early Earth was a chaotic chemical soup. Somewhere in that mix were alpha-hydroxy acids (αHAs), simple organic molecules that could have rained down from space or been cooked up by lightning strikes. When these compounds were dehydrated—say, by a hot, dry spell—they could polymerize into polyesters. Then, when they got wet again, they formed microdroplets, tiny compartments that could, in theory, have played a role in the development of life.

So far, so good. But there was a catch. Previous lab experiments had only managed to produce these droplets in conditions that were arguably too “ideal”—high concentrations of αHAs, large volumes of water, and relatively stable environments. Which is great, if you think life started in a massive primordial soup bowl. But let’s be honest, early Earth wasn’t a neatly controlled lab. It was a chaotic, messy place, full of fluctuating conditions, briny puddles, and tiny rock crevices.

That’s where the latest research comes in.

Protocells in the Wild: More Common Than We Thought?

A new study, led by Mahendran Sithamparam at the Space Science Center (ANGKASA) in Malaysia, alongside researchers from Tokyo’s Earth-Life Science Institute (ELSI), decided to push the limits. Instead of relying on high concentrations of αHAs in nice, spacious reaction volumes, they tested whether these microdroplets could form in more challenging environments—smaller volumes, lower concentrations, and saltier conditions.

And surprise, surprise: it turns out polyester microdroplets are quite adaptable. The researchers found that these structures could emerge at much lower concentrations than previously thought—just 1mM PA (phenyllactic acid, a type of αHA) in 500 µL of water was enough. That means protocells didn’t need huge, nutrient-rich lakes to form. They could have been cropping up in tiny rock pores, evaporating puddles, or anywhere that saw intermittent wet-dry cycles.

Then they threw another curveball at the theory: salt. Early Earth wasn’t just a pure-water paradise—it was salty and not just in one uniform way. The team introduced different salts (NaCl, KCl, and MgCl₂) at levels mimicking ancient seawater. The result? Polyester droplets formed just fine in NaCl- and KCl-rich environments, but MgCl₂ shut things down completely. That’s crucial because it suggests these protocells were more likely to appear in certain types of water bodies—think salty lakes and oceanic pools—while being absent in high-MgCl₂ environments.

So What? (Or, Why Should You Care?)

If polyester protocells were this widespread, it would completely change the way we think about life’s origins. Instead of needing rare, specific conditions, these early compartments could have formed all over the place. Tiny rock crevices, salty puddles, coastal brine—you name it. And if they were common on early Earth, there’s a good chance similar processes could be happening elsewhere in the universe.

Tony Z. Jia, one of the study’s co-authors, puts it bluntly: “By pushing the boundaries of polymerization under realistic settings, we were able to test whether these structures could have viably assembled on early Earth.” Translation? The more we test these protocells in unpredictable conditions, the more likely it seems that they were everywhere.

And if early Earth was covered in these messy, membraneless droplets, the big question isn’t if life got started—it’s where it happened first. And, just maybe, whether it’s happening somewhere else right now.