origin of life

Small charges in water spray can trigger the formation of key biochemicals

biochemistry, Biology, chemistry, origin of life, Physics, Science / Beth Washington / March 16, 2025

Once his team nailed how droplets become electrically charged and how the micro-lightning phenomenon works, they recreated the Miller-Urey experiment. Only without the spark plugs.

Ingredients of life

After micro-lightnings started jumping between droplets in a mixture of gases similar to that used by Miller and Urey, the team examined their chemical composition with a mass spectrometer. They confirmed glycine, uracil, urea, cyanoethylene, and lots of other chemical compounds were made. “Micro-lightnings made all organic molecules observed previously in the Miller-Urey experiment without any external voltage applied,” Zare claims.

But does it really bring us any closer to explaining the beginnings of life? After all, Miller and Urey already demonstrated those molecules could be produced by electrical discharges in a primordial Earth’s atmosphere—does it matter all that much where those discharges came from? Zare argues that it does.

“Lightning is intermittent, so it would be hard for these molecules to concentrate. But if you look at waves crashing into rocks, you can think the spray would easily go into the crevices in these rocks,” Zare suggests. He suggests that the water in these crevices would evaporate, new spray would enter and evaporate again and again. The cyclic drying would allow the chemical precursors to build into more complex molecules. “When you go through such a dry cycle, it causes polymerization, which is how you make DNA,” Zare argues. Since sources of spray were likely common on the early Earth, Zare thinks this process could produce far more organic chemicals than potential alternatives like lightning strikes, hydrothermal vents, or impacting comets.

But even if micro-lightning really produced the basic building blocks of life on Earth, we’re still not sure how those combined into living organisms. “We did not make life. We just demonstrated a possible mechanism that gives us some chemical compounds you find in life,” Zare says. “It’s very important to have a lot of humility with this stuff.”

Science Advances, 2025. DOI: 10.1126/sciadv.adt8979

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Tiny cracks in rocks may have concentrated chemicals needed for life

biochemistry, Biology, chemistry, geology, origin of life, Science / Shannon Garcia / April 5, 2024

Cartoon of a geologically active area, showing sub-surface channels in different colors to represent various temperatures. — Enlarge / Active geology could have helped purify key chemicals needed for life.

Christof B. Mast

In some ways, the origin of life is looking much less mystifying than it was a few decades ago. Researchers have figured out how some of the fundamental molecules needed for life can form via reactions that start with extremely simple chemicals that were likely to have been present on the early Earth. (We’ve covered at least one of many examples of this sort of work.)

But that research has led to somewhat subtler but no less challenging questions. While these reactions will form key components of DNA and protein, those are often just one part of a complicated mix of reaction products. And often, to get something truly biologically relevant, they’ll have to react with some other molecules, each of which is part of its own complicated mix of reaction products. By the time these are all brought together, the key molecules may only represent a tiny fraction of the total list of chemicals present.

So, forming a more life-like chemistry still seems like a challenge. But a group of German chemists is now suggesting that the Earth itself provides a solution. Warm fluids moving through tiny fissures in rocks can potentially separate out mixes of chemicals, enriching some individual chemicals by three orders of magnitude.

Feeling the heat (and the solvent)

Even in the lab, it’s relatively rare for chemical reactions to produce just a single product. But there are lots of ways to purify out exactly what you want. Even closely related chemicals will often differ in their solubility in different solvents and in their tendency to stick to various glasses or ceramics, etc. The temperature can also influence all of those. So, chemists can use these properties as tools to fish a specific chemical out of a reaction mixture.

But, as far as the history of life is concerned, chemists are a relatively recent development—they weren’t available to purify important chemicals back before life had gotten started. Which raises the question of how the chemical building blocks of life ever reached the sorts of concentrations needed to do anything interesting.

The key insight behind this new work is that something similar to lab equipment exists naturally on Earth. Many rocks are laced with cracks, channels, and fissures that allow fluid to flow through them. In geologically active areas, that fluid is often warm, creating temperature gradients as it flows away from the heat source. And, as fluid moves through different rock types, the chemical environment changes. The walls of the fissures will have different chemical properties, and different salts may end up dissolved in the fluid.

All of that can provide conditions where some chemicals move more rapidly through the fluid, while others tend to stay where they started. And that has the potential to separate out key chemicals from the reaction mixes that produce the components of life.

But having the potential is very different from clearly working. So, the researchers decided to put the idea to the test.

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