Fascinating news: Mongolian and Iberian aurochs influenced cattle; another dwarf aurochs described

The last few months saw the publication of three very interesting papers on the aurochs. One analyzed ancient genomes of Mongolian aurochs and found that it influenced ancient Mongolian domestic cattle, an influence that lives on in a breed you would never expect. Another one analyzed bovine material from the Holocene of Spain, and found significant introgression from Iberian aurochs into cattle. The third paper describes another aurochs dwarf form or subspecies, this time from a Greek island. 

-) Mongolian aurochs influenced Mongolian cattle 

Aurochs material from Mongolia was analyzed and all of them had the mitochondrial haplotype C (which was also found in Chinese aurochs assigned to B. p. suxianensis and is distinct from the European haplotypes). It turns out that B. p. suxianensis influenced local Mongolian cattle, which is what I expected because I consider it very likely that introgression from wild to domestic occurred anywhere aurochs and cattle lived side by side. However, modern Mongolian cattle are different from ancient Mongolian cattle. In modern cattle, Mongolian aurochs influence was detected Hereford. This is rather surprising. 

In the phylogenetic analysis, haplotype C is a sister group to the western Eurasian haplotypes, forming a clade that is a sister group to haplotype R, which was found in African aurochs. The Indian haplotypes (from zebu) are an outgroup to all the other haplotypes of the species detected so far. This indicates that the European aurochs was closer to the East-Asian aurochs than to the African aurochs, and that the Indian aurochs was the result of the first cladogenesis event in Bos primigenius that we know of. 

Brunson et al.: Ancient Mongolian aurochs genomes reveal sustained introgression and managment in East Asia. 2023 (preprint) 

-) Iberian aurochs influenced western European cattle 

Archaeological material from the late Holocene of Spain was analyzed and the fully resolved British aurochs genome used as a reference for pure aurochs. It was found that some remains were up to 90% aurochs, others as low as 20% and the rest, respectively, domestic. This indicates that domestic cattle and aurochs hybridized frequently, leading to introgression to both wild and domestic populations. The data suggests that male introgression from aurochs was more common than female introgression, which is something that I expected because of the handling of cattle back in early days. They were kept free all year round, where wild bulls could have easily mated with domestic cows - a behaviour that is also historically documented (Schneeberger). It gets even more interesting: The genomes of modern western European cattle breeds are between 20 and 25% aurochs. Lidia was also tested, but did not show a higher portion of aurochs. The authors, however, speculate that the aurochs material preserved in Lidia might be key genes for behaviour and appearance, explaining the high degree of similarity between aurochs and Spanish fighting cattle. I too consider this highly likely. 

Günther et al.: The genomic legacy of Human management and sex-biased aurochs hybridization in Iberian cattle. 2023 (preprint). 

-) Bos primigenius thrinacius 

Previously to the new paper, two insular dwarf aurochs subspecies were described: B. p. siciliae on Sicily and B. p. bubaloides on Pianosa, Pleistocene of Italy. There are also remains from Malta which may constitute a third insular subspecies that has not yet been formally described. Now another one, from Kythera Island, Greece, has been described. It seems to be the smallest of the dwarf aurochs, slightly smaller than B. p. bubaloides, which had a withers height of 100-120 cm. No complete skeleton of B. p. thrinacius has been recovered, unfortunately. But what is known seems to suggest that the sexual dimorphism was reduced, and there was a tendency to loose premolar 2 in the dentals preserved. The dentals also look comparably short to me by aurochs standards. I would say this is in line with general tendencies of insular mammals to show signs of paedomorphy, similar to domestics. The study was co-authored by Roberto Rozzi, who did a lot of interesting research on insular bovids. 

Siarabi et al.: Insular aurochs (Mammalia, bovidae) from the Pleistocene of Kythera Island, Greece. Quaternary Science Reviews (2023).