October 14, 2008

Y chromosomes of Neolithic cattle do not suggest hybridization with European aurochsen

A previous study (pdf) had proposed that there was Y-chromosome evidence for introgression of native European Y-chromosomes into Neolithic cattle. Some previous posts on the mtDNA evidence.

From the paper:
In conclusion, the ancient distribution of the Y1 and Y2 haplotypes suggests that they do not discriminate European and Near Eastern Y-chromosomal lineages. As a consequence, there is still no patrilinear marker for investigating possible male introgression between imported cattle and European aurochs. So far, the importation of taurine cattle from its Near Eastern centre of domestication into Europe without subsequent hybridisation with local wild cattle populations remains the preferred model for the origin of European cattle.

From this paper, Figure 1 has the "Assumed distribution of aurochs mt-haplogroups in Western Eurasia", Figure 2 has the ancient Y data.

PLoS ONE 3(10): e3418. doi:10.1371/journal.pone.0003418

Y-SNPs Do Not Indicate Hybridisation between European Aurochs and Domestic Cattle

Ruth Bollongino et al.



Previous genetic studies of modern and ancient mitochondrial DNA have confirmed the Near Eastern origin of early European domestic cattle. However, these studies were not able to test whether hybridisation with male aurochs occurred post-domestication. To address this issue, Götherström and colleagues (2005) investigated the frequencies of two Y-chromosomal haplotypes in extant bulls. They found a significant influence of wild aurochs males on domestic populations thus challenging the common view on early domestication and Neolithic stock-rearing. To test their hypothesis, we applied these Y-markers on Neolithic bone specimens from various European archaeological sites.

Methods and Findings

Here, we have analysed the ancient DNA of 59 Neolithic skeletal samples. After initial molecular sexing, two segregating Y-SNPs were identified in 13 bulls. Strikingly, our results do not support the hypothesis that these markers distinguish European aurochs from domesticated cattle.


The model of a rapid introduction of domestic cattle into Central Europe without significant crossbreeding with local wild cattle remains unchallenged.



Maju said...

I am confused. Bollognino's study and comparison is good but, if Y2 is also an auroch haplogroup as he suggests, then it is not proven that there was no hybridation. And Gotherstrom's samples still appear to show a good deal of Y1 apparent hybrids, even if concentratd in a small area, and modern European cattle is anyhow dominated by this haplogoup. Bollognino himself finds one of those in a different area: Rumania.

If both haplogroups existed in West Asian and European wild cattle before domestication, then nothing can be proven via genetics (except that both populations were extremely close and could interbreed very easily).

Therefore the issue of phenotypical growth of European cattle since Starcevo culture remains fully open (and IMO a high probability).

Bognollino might have been more conclusive if he had researched preneolithic wild aurochs of West Asia or even very early Neolithic cattle in the same region and found some Y1 there, something that is only speculation so far.

terryt said...

I agree that "it is not proven that there was no hybridation".

The authors say, "we have analysed the ancient DNA of 59 Neolithic skeletal samples". The results would be more conclusive if they'd analysed ancient DNA from West European aurochsen as well as the group Maju suggests.

It's almost inconceivable that the odd local wild bull didn't impregnate the odd domestic cow. But people still seem to be obsessed by the idea that evolution is linear.

I'd actually look for aurochsen Y-chromosome specifically in jersey cattle. They seem to preserve the main original European aurochs colouration at least.

pconroy said...

I'd check among the White Park Cattle

Maju said...

I'd actually look for aurochsen Y-chromosome specifically in jersey cattle.

I'd check among the White Park Cattle

I guess all or nearly all European cattle may have some auroch genes. Most of the modern breeds are actually more a product of artificial selection than just a matter of ancestry, right?

Anyhow, consider also please the Basque betizu breed: half wild, big, red, with large lire-shaped horns... Also, I guess that the brave bull breed used for bullfights may keep some of the fierceness (and therefore genetics) of the wild ancestors of domestic cattle (but in this case intentional breeding may have been more important in the final result, whatever the genes selected).

terryt said...

Thanks for that link Maju. I'm interested in cattle, having been brought up on a dairy farm.

The reason I mentioned jerseys is that the bulls and cows are usually a different colour. Bulls are quite dark with a lighter back while the cows are more uniformly pale brown with some dark around their head. I've seen Paleolithic cave paintings of Aurochs that show this dimorphic colour system although it seems unusual in european cattle generally. Therefore I suspect it's a primitive trait.

Typical jersey cow:


Jersey bull (although he has more white than is usual):


pconroy said...

Terry, Maju,

If your looking mostly at coloration, then take a look at the Limousin Cattle:

They're an ancient beef bred from Southern France - we used to cross them with Frisians when I was a kid.

pconroy said...

Likewise for cave paintings of ponies - check out the Exmoor:



We had one when I was a kid.