The asteroid impact that wiped out the dinosaurs 66 million years ago may have also set off a genetic chain reaction that helped ants become one of the most successful animal groups on Earth, according to new research tracing a century of ant evolution through mobile segments of DNA known as transposable elements, or "jumping genes."
Today's ants form the largest family of social insects, with more than 15,000 known species. The new study, published in Science Advances and led by Dr. Lukas Schrader of the Institute for Evolution and Biodiversity at the University of Münster, compared the genomes of 163 ant species across twelve of the sixteen surviving ant subfamilies to reconstruct how these jumping genes behaved over the past 100 million years.
From genomic parasites to evolutionary fuel
Jumping genes copy themselves and relocate within a genome, and scientists long viewed them mainly as "genomic parasites" that multiply without benefiting their host, occasionally contributing to disease. More recent research has shown they can also create raw material for evolutionary change. Schrader's team found that ant lineages with the most jumping-gene activity also tend to have the most species living today — and that several major lineages experienced separate bursts of that activity during the early Paleogene period, right after the asteroid struck, shortly before those groups began diversifying into the thousands of species seen now.
"The asteroid impact had dramatic consequences for the environment," Schrader said. "We have now found the genomic mechanism that connects these ecological upheavals to the subsequent rapid diversification of the ants: transposable elements." He noted that other animal groups, including primates and bats, show similar patterns linking bursts of jumping-gene activity to bursts of new species.
The study also found a connection between jumping genes and the expansion of gene families tied to odorant receptors, which ants rely on almost universally to navigate, recognize colony members and coordinate behavior through chemical signals. The researchers suggest that by helping expand these smell-detection genes, jumping genes may have sharpened the chemical communication systems that make complex ant societies possible — turning what was once dismissed as genomic clutter into a plausible engine behind one of evolution's great success stories.
