Beetle Droppings May Have Helped Yeast Genes Jump Between Species
Genes are usually passed from parent to offspring. Sometimes, though, they jump sideways — from one species to another. Scientists at the University at Buffalo have traced one such jump, involving yeast, an ancient virus, and possibly the droppings of wood-eating beetles.
The study, published on 31 October 2026 in Molecular Biology and Evolution and announced by the University at Buffalo on 2 November 2026, looks at yeasts in the genus Scheffersomyces. These yeasts live on rotting wood and in the guts of beetles and other wood-eating insects, where they help their hosts digest wood. They are also studied for their promise in biofuel research.
A virus's genes, still going after 15 million years
The researchers found that genetic material from an ancient virus has evolved into a cluster of four related genes, which they named STORM — short for Scheffersomyces Totivirus-like ORF Repeat Module. The cluster has persisted in yeast genomes for at least 15 million years. Yet its genes have evolved at unexpectedly high rates: about seven times faster than their counterparts in related viruses.
The ancient virus was related to modern totiviruses, a kind of RNA virus. Unlike retroviruses such as HIV, totiviruses lack the machinery to convert their RNA into DNA and insert it into a host's genome on their own. The researchers believe the viral RNA was somehow copied into DNA and incorporated into the yeast genome. Corresponding author Derek Taylor, professor of biological sciences at Buffalo, says: "To our knowledge, this is the first documented example of horizontal transfer of a cluster of duplicated genes derived from an ancient RNA virus."
Horizontal gene transfer is the movement of genetic material between organisms without ordinary reproduction. The evidence here is in the family trees: the STORM genes' evolutionary histories did not match those of the yeast species carrying them, which suggests the genes moved between species rather than simply being inherited from common ancestors. The study found the cluster moved between different species of these yeasts at least three times.
How beetles may have helped
The researchers suspect — this part is a hypothesis, not a proven fact — that wood-eating insects brought different yeast species together. Several yeast species can coexist in a beetle's gut, and multiple species can also occur together in insect droppings and chewed wood near rotting wood. That closeness creates opportunities for genetic exchange. As Taylor puts it: "In order to exchange genomic material, you have to be in the same place at the same time."
At least one transfer appears to have happened through a transposon, or "jumping gene" — a segment of DNA that can move within genomes and sometimes between species. Because STORM and a neighbouring jumping gene show the same unusual evolutionary history, the team suspects the transposon may have carried STORM between yeast species as extra cargo.
What the genes do is still a mystery
One of the study's most unusual findings is that the four genes, despite sharing a common viral origin, have followed different evolutionary paths. Some have kept more of their ancestral virus-like protein structures; others have changed extensively. All four are transcribed into RNA, and there is evidence that at least one produces a protein. Natural selection appears to have preserved certain features, which suggests those features still matter — but exactly what STORM does remains unknown. Taylor suspects the genes may help yeast cope with stress, since totiviruses can act as a kind of "frenemy", helping the host deal with physiological stress under some conditions.
The next step, the researchers say, is to grow yeasts under different environmental stresses and see whether the STORM genes respond differently.
For students, this is evolution you can picture: tiny organisms sharing a log, a beetle's gut, or a dropping — and genes quietly changing address. It is also a reminder to separate what is shown (the genes moved) from what is suspected (how the beetles helped) and what is still unknown (what the genes do).
If your child is curious about how living things change over millions of years — or how scientists read that history from DNA — a first lesson in biology can start on a rotting log and end with genes that outlived the virus they came from. Book your first lesson
Sources:
- University at Buffalo, "Beetle poop may have helped shape millions of years of yeast evolution", 2 November 2026: https://www.buffalo.edu/news/releases/2026/11/beetle-poop-may-have-helped-shape-millions-of-years-of-yeast-evolution.html
- Taylor, D. et al., study published 31 October 2026 in Molecular Biology and Evolution, as reported by the University at Buffalo.
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