May 10: Using microbes to solve crimes, and more…
Anus origins, deepfake detectors, crows do geometry, magnetars make gold, and territorial caterpillars
On this week's episode of Quirks & Quarks with Bob McDonald:
Our distant evolutionary ancestors had no anuses. Their waste was excreted from the same orifice they used to ingest food, much like jellyfish do today. Now, in a new study on bioRxiv that has yet to be peer-reviewed, scientists think they've found the evolutionary link in a worm with only a single digestive hole. Andreas Hejnol, from Friedrich Schiller University Jena, said he found genes we now associate with the anus being expressed in the worms in the opening where its sperm comes out, suggesting that in our evolutionary history, a similar orifice was co-opted as a butt hole.
Detecting deepfake videos generated by artificial intelligence is a problem that's getting progressively worse as the technology continues to improve. One way we used to be able to tell the difference between a fake and real video is that subtle signals revealing a person's heart rate don't exist in artificially generated videos. But that is no longer the case, according to a new study in the journal Frontiers in Imaging. Peter Eisert, from Humboldt University and the Fraunhofer Heinrich-Hertz-Institute HHI in Germany, said detecting manipulated content visually is only going to become a lot more difficult going forward.
Crows are known to be among the most intelligent of animals, and a new study has explored their geometrical sophistication. Researchers including Andreas Nieder from the University of Tübingen found that crows can recognize and distinguish different kinds of quadrilateral shapes, an ability we had thought was unique to humans. The research was published in the journal Science Advances.
Astronomers have discovered a new source of the universe's heavy elements — things like gold, platinum and uranium. A study led by astrophysicist Anirudh Patel found that magnetars — exotic neutron stars with ultra-powerful magnetic fields — may produce these elements in a process analogous to the way solar flares are produced by our Sun. The research, published in The Astrophysical Journal Letters, found that a single flare from a magnetar could produce the mass equivalent of 27 moons' worth of these heavy elements in one burst.
It may not be big, but it's small — and stroppy!
You might not expect an insect so tiny you need a magnifying glass to see it properly to be an aggressive defender of its territory, but that's because you likely haven't met the warty birch caterpillar. Its territory is just the tip of a birch leaf, but it defends it by threatening intruders with vigorous, if not precisely powerful, vibrations. Jayne Yack at Carleton University has been studying this caterpillar since 2008. This research was published in the Journal of Experimental Biology.
Scientists have developed a new tool that can track location based on traces of the bacteria characteristic to different places. Eran Elhaik, from Lund University in Sweden, trained the AI tool using nearly 4,500 microbiome samples collected around the world from subway systems, soil and the oceans. He said they could identify the city source in 92 per cent of their urban samples, and in Hong Kong, where a lot of their data came from, they could identify the specific subway station samples were taken from with 82 per cent accuracy. The study was published in the journal Genome Biology and Evolution.
