Unknown wild goat lineage from ten millennia ago

Oct. 6 () –

Geneticists at Trinity College Dublin, together with a team of international collaborators, have discovered a previously unknown lineage of wild goats more than ten millennia old.

The new type of goat, discovered from a genetic examination of skeletal remains and known as “the Taurasian tur”, probably survived the Last Glacial Maximum (the ice age), which left its ancestors stranded on the high peaks of the Taurus Mountains in Turkey, where their remains were found. The finding has been published in eLife.

More than 12,000 years ago, hunter-gatherers in the Taurus Mountains of southern Turkey relied heavily on local game for food and subsistence. Located near the present-day village of Döngel and at a height of 1,100 meters above sea level, Direkli Cave was used for approximately three millennia (14,000-11,000 years ago) as a seasonal camping for these hunters and may have been inhabited throughout the year.

“Among the artifacts found in Direkli cave were large amounts of skeletal remains with various marks of processing, indicating that wild goats were slaughtered there for consumptionsays Dr Kevin Daly, from the Trinity School of Genetics and Microbiology, who is the first author of the research.

“With the cave surrounded by high peaks, reaching 2,200 meters, the ibex or bezoar ibex (Capra aegagrus) that inhabit the region today probably were the target of these late Pleistocene hunters“.

During the genetic selection of goat skeletal remains from Direkli, geneticists noticed something unusual: many of the goats carried mitochondrial genomes similar to a different species of wild goat.

While the domestic goat is derived from the bezoar ibex, other wild goat species are still alive today and are found in relatively restricted regions. These include the East and West Caucasian tur, two sister species (or subspecies) of wild goat now found only in the Caucasus Mountains of Georgia. Many of the Direkli Cave samples contained mitochondria related to these Caucasian tur, despite the fact that the Direkli cave is located about 800 kilometers from its current habitat.

Dr Daly added: “An even bigger surprise came when we examined the nuclear genomes of the Direkli cave goats: while most resembled the bezoar ibex, as expected, one sample looked different from the rest. sample, Direkli4, showed more ancestral genetic variants than other Direkli goats, indicating that it might have been a different species than the others.”

To better understand this, the Trinity team collaborated with researchers at the Muséum national d’Histoire naturelle in Paris to generate genetic data for other species in the Capra group.

The team was surprised to see that the Direkli4 sample did, in fact, cluster with the Caucasian Tur, which appeared to be a sister group to the East and West types. Intrigued, the team examined more material from Direkli Cave and found two additional samples with a “tur-like” genome, suggesting that a population of these Tur relatives lived in the Taurus Mountains near the local bezoar ibexand both were hunted by humans in prehistoric times.

The team suggests a name for the discovered Taurasian tur: Capra taurensis or Capra caucasica taurensis; researchers still classify living tur as subspecies or as two distinct species.

As the tur are larger and heavier than other wild goats, with a distinctive horn shape, it should be possible to identify a group of tur relatives in the animal remains. Horn remains are absent from Direkli Cave, despite the large number of remains, possibly pointing to these being a valuable prize among hunters. But the team’s archaeozoologists showed that there were many large-bodied goats in Direkli cave, and possibly in other mountainous locations in Southwest Asia.

“We hope this will encourage re-evaluation and analysis of the faunal remains in the region, as some interesting discoveries may yet be found,” added Dr Daly.

The team suggests that the ancestors of the Tur lived in a wider geographic area for the past 100,000 years, from the Caucasus Mountains to the Taurus Mountains in the Mediterranean, and that climate change may have caused habitat fragmentation.

“The Last Glacial Maximum, or ice age, may have made many areas inhospitable, forcing these goats to compete with other species. The Taurasian tur may have been a leftover group, restricted to the peaks of the Taurus mountains . Increased human activity would have put additional pressure on the Taurasian tur, with hunting evidenced at Direkli CaveDr Daly said.

“While we don’t know exactly when or how this lineage of goats became extinct, additional genomic studies in the region could show that their genomes live on in today’s wild goats.”