paleogenomics

Scientists sequence a woolly rhino genome from a 14,400-year-old wolf’s stomach

Megafauna, megafaunal extinction, paleoecology, paleogenomics, Science, siberia, woolly rhino / Mike M. / January 14, 2026

That came as a surprise, since woolly rhinos disappear from the fossil record about 400 years later. Already, the species was making its last stand in northeastern Siberia; its range had been shrinking eastward since around 35,000 years ago. But apparently, on the cusp of extinction, the species was still doing pretty well in northeastern Siberia (except for this particular rhino, who got eaten by a wolf after what one can only assume was a bad day).

This is the piece of woolly rhino meat in question, extracted from the stomach of a wolf puppy who lived near the end of the last Ice Age. Guðjónsdóttir et al. 2026

Woolly rhino population was small but healthy

So what counts as a stable population?

In the genome of a 49,000-year-old woolly rhino from a few hundred miles east in Rakvachan, Siberia, Guðjónsdóttir and her colleagues found clues about the species’ even more ancient history. Big changes in population size, among other events, can leave traces in the genome, and the researchers used those to estimate that between 114,000 and 63,000 years ago, the woolly rhino population dropped sharply, from about 15,600 to about 1,600.

Those numbers refer to what ecologists call the “effective population,” which means the number of rhinos breeding and contributing to the group’s gene pool (so there would have been more than 1,600 running around, but not all of them were reproducing). After 63,000 years ago, the woolly rhino population seems to have leveled out.

According to ecologists, an effective population of 1,600 rhinos would have been more than enough to keep the species thriving. Smaller populations, especially with shrinking ranges, are more vulnerable to being wiped out by events like environmental change, natural disasters, or disease outbreaks. And small populations are also more likely to face the genetic consequences of inbreeding, a loss of genetic diversity, and genetic drift (in which potentially harmful mutations can pile up), leaving the species even more vulnerable. The whole thing can turn into a vicious cycle.

For most species, the threshold for avoiding those genetic pitfalls is an effective population of around 1,000.

The end came suddenly for woolly rhinos

Researchers had expected to find woolly rhinos in dire straits by 14,400 years ago. Prior to discovering the Tumat genome inside a wolf’s stomach, the most recently sequenced woolly rhino genome dated to 18,400 years ago (and it was found just a few miles from the Rakvachan rhino). That genome showed all the signs of a healthy, stable population. But by 14,000 years ago, woolly rhinos disappeared from the fossil record—so it looked like their population must have started its death spiral shortly after 18,400 years ago.

Scientists sequence a woolly rhino genome from a 14,400-year-old wolf’s stomach Read More »

Study: DNA corroborates “Well-man” tale from Norse saga

The results: The Well-man was indeed male, between 30 and 40, with blue eyes and blond or light-brown hair, and his ancestry was traced to southern Norway, most likely present-day Vest-Agder. This is interesting because King Sverre’s men were from central Norway, and it had long been assumed that the dead body thrown into the well was part of that army. It was the invading Baglers who hailed from southern Norway. The authors are careful to note that one cannot definitively conclude that therefore the Well-man was a Bagler, but it’s certainly possible that the Baglers tossed one of their own dead into the well.

As for whether the action was a form of 12th-century biological warfare intended to poison the well, the authors weren’t able to identify any pathogens in their analysis. But that might be because of the strict decontamination procedures that were used to prepare the tooth samples, which may have also removed traces of any pathogen DNA. So they could not conclude one way or another whether the Well-man had been infected with a deadly pathogen at the time of his death.

Seven well-man teeth recovered from excavation — Seven Well-man teeth recovered from the excavation. Credit: Norwegian Institute for Cultural Heritage Research

“It was a compromise between removing surface contamination of the people who have touched the tooth and then removing some of the possible pathogens. There are lots of ethical considerations,” said co-author Martin Ellegaard, also of the Norwegian University of Science and Technology. “We need to consider what kind of tests we’re doing now because it will limit what we can do in the future.”

The fact that the Well-man hailed from southern Norway indicates that the distinctive genetic drift observed in southern Norway populations already existed during King Sverre’s reign. “This has implications for our understanding of Norwegian populations, insofar as it implies that this region must have been relatively isolated not only since that time, but also at least for a few hundred years beforehand and perhaps longer,” the authors concluded. Future research sequencing more ancient Norwegian DNA would shed further light on this finding—perhaps even the remains of the Norwegian Saint Olaf, believed to be buried near Trondheim Cathedral.

iScience, 2024. DOI: 10.1016/j.isci.2024.111076 (About DOIs).