Biologists Say They Cracked One Of Lifes Biggest Mysteries Sabine

TITLE: Biologists Say They Cracked One of Life’s Biggest Mysteries CHANNEL: Sabine Hossenfelder DATE: 2026-05-19 ---TRANSCRIPT--- Life on Earth has a peculiar property which is that many biological molecules have a handedness. The DNA twists one way and not the other and all the rest must fit to this. But why is this so? Scientists have now found what may be the first plausible explanation. Let’s have a look. The basic problem is this. Many biological molecules come into mirror image versions. They’re like your left and right hands. same part, same connections, but not the same shape. Such molecules are called chyro. Life on Earth uses only one version. RNA and DNA use right-handed sugars, while proteins use left-handed amino acids. The mirror image version of life is chemically as possible as ours, but it’s not the version we see. The question of why life on earth uses only one corality is relevant beyond earth. Because if the reason for the corality on our planet is universal based on some fundamental facts about nature then it be the same on all other planets that could host life. If on the other hand it’s coincidence or due to some quirk of our particular planet then life on other planets could evolve differently. It might look the same but behave differently when combined with our molecules. So far the best explanation has been that one corality of the molecules favored by magnetic rocks. Some rocks on earth are naturally magnetic such as iron containing compounds. Their surfaces can aid the formation of complex molecules by a sort of crystallization process. But the corality of the molecules which are aided by the magnetic rocks then depends on the direction of the magnetization. There have been previous studies about this and we actually talked about this two years ago. The magnetization does not make a huge difference but it’s a measurable difference and the idea is that this small difference eventually leads to a competitive advantage in the reproduction of one molecule corality over the other. The issue with this explanation is though that it just pushes the problem around because now you’d have to explain why one magnetization of rocks is more likely than the other. One might try to blame the Earth’s magnetic field, but this isn’t particularly plausible. It’s too weak and also the Earth’s magnetic field isn’t the same everywhere and it changes in time. The authors of the new paper now say they found a better explanation. They say that one corality of molecules is better at transporting electrons. Period. To test this, they made chyro gold films. Gold is not normally chyro, but they grew the films in solutions containing either left or right-handed tartric acid. The chyro additive biases the microscopic structure of the growing metal film. Then they sent an electric current through the film and measured the sideways voltage. This tells them how well electrons move through the chyal metal. They found that the left and right-handed samples gave an opposite direction of the current as expected, but they were not of equal size. In other words, one-handed version was not simply the mirror image of the other. One was better period. What does chyro gold have to do with life? Nothing directly. But chemistry is ultimately all about where electrons like to go. Each time molecules interact, the likelihood of that working depends on the transport of electrons. So this is why their experiment could indeed explain why chemical reactions favor one corality over the other. If they’re correct, this would be a big deal. By the way, if you enjoy my science news, please consider supporting me on Patreon or right here on YouTube. A big thank you to all supporters, especially those in Patreon tier 4 and higher. This channel would not be possible without your help. So yes, this new study could solve a big problem, but I don’t see how this can possibly be correct. This isn’t my research area, but as a physicist, I believe I’m entitled to opinions on everything and anything. And I think that this measurement, if correct, violates some basic physical principles. really these currents should have the same magnitude. They address this in the paper by saying it’s a complicated non-equilibrium process with some difficult maths and so on. But I don’t see how this can possibly explain it. The standard model of particle physics does violate car symmetry, but this effect is extremely tiny and plays no role at the tiny energies that they measure in this experiment. So that doesn’t explain it either. I suspect it’s more likely they have a problem with their sample preparation than that they found physics beyond the standard model. So, I’m afraid I have to give this paper a 9 out of 10 on the meter. It’s not a 10 because it’s really outside my research area. And I grant the possibility that I’m just too dumb to understand what they’re doing. Unlike their current, though, that possibility has the same magnitude in the mirror image. So in summary, if this result is correct, it could change our understanding of life in the universe. If it’s wrong, it’ll change our understanding of how carefully one should prepare a sample. Both are important, but only one gets into a textbook. Personally, I hope molecules don’t have the same handedness everywhere because then at least aliens might think a moment before they eat us.