New photos from the Auerrind project

 Claus Kropp has recently posted some new photos of the cattle from the Auerrind project: 

left: Maremmana x Sayaguesa, right: Maremmana x Watussi (© Claus Kropp)

Maremmana x Watussi (© Claus Kropp)

(Maremmana x Watussi) x (Sayaguesa x Chianina) (© Claus Kropp)

Maremmana x Sayaguesa (©Claus Kropp)

The Maremmana x Sayaguesa bull seems to develop formidable horns. I love his curly hair on the forehead, a typical trait of the European aurochs. The Maremmana x Watussi bull has large horns as well. On Facebook, Claus Kropp wrote that a pure Sayaguesa or Sayaguesa x Chianina might be crossbreeding options for this bull, and I completely agree with that. The young (Maremmana x Watussi) x (Sayaguesa x Chianina) bull should be old enough to have its final colour, apparently it inherited some colour dilutions. However, if it gets large and well-proportioned I would still consider him a useful individual (colour is easy to breed), especially if he gets good horns. 

The Holocene European wild horse

Recently I did a life reconstruction for the Holocene European wild horse: 

Since there is not a single complete skeleton of a Holocene European wild horse, I based the body, head and proportions on Przewalski's horses and also primitive pony breeds. A recent study suggests that Holocene European wild horses were predominantly black [1]. As for the mane, it cannot be ascertained today if the western wild horse subspecies, Equus ferus ferus, had an erect mane or a falling mane. All cave paintings show erect manes, and all extant wild equines have an erect mane. It has been suggested that a falling mane would be advantageous in a more humid climate because it diverts rain water, but domestic horses were domesticated in the arid steppe. It is well possible that a falling mane is a trait that arose during domestication. Hence, I drew my horse with an erect mane. 

[1] Sandoval-Castellanos et al.: Coat colour adaption of post-glacial horses to increasing forest vegetation. 2017

Why do some Polish koniks have erect manes?

While searching on google for Konik horses from Poland, which is where the breed originated and should have the most genetic diversity, I found a number of individuals with an erect mane. See this young individual, this one from Popielno (one of the main Konik breeding sites), or this one from the Roztoczanski Park Narodowy. Why is that? 

Some Heck horses, which are almost one popualtion with the Konik in Germany, have erect manes because Lutz Heck bred with a Przewalski stallion and Przewalski's horses have been crossed-in again at the Wildpark Hardehausen in order to achieve an erect mane. The results can be seen here. Breeders in Germany often do not differentiate between Koniks and Heck horses, so that the breeds are often intermixed. 

However, the Koniks in Poland should be free of that comparably recent intermixture, as Heck horses are found mostly in Germany. Nevertheless it is possible that even "pure" modern Koniks have Przewalski introgression. The reason for that is that some of the Koniks that have been used in Lutz Heck's experiment were returned to Poland after the war. It is well possible that some of these Koniks were part Przewalski's horse due to Heck's breeding. The fact that some Polish koniks have erect manes endorses this assumption, at least in my opinion, as I find no other explanation for this trait in the Polish stock. 

Probably only a genetic test could bring clarification. 

Genetic breeding-back?

Some modern aurochs projects claim they carry out selective breeding on a genetic level. In an article from 2017, I outline why I doubt this. First of all, we have every reason to assume that a lot of, or at least some, key wildtype alleles have been lost during the process of domestication. Furthermore, although the full genome of an aurochs has been resolved, the wildtype alleles of this specimen have not been traced down in modern cattle individually so that selective breeding for those alleles would be possible. And lastly, the number of involved loci might be very, very high and the selection would probably be a century-long project. 

Another practical problem for "genetic selection" would be genetic linkage. Genes do not get passed on individually, but are inherited via chromosomes. Let us say we have ten key aurochs alleles on ten loci on the same chromosome. Breed A has five of those alleles on the loci 1-5, and mutated (=domestic) alleles on loci 6-10. Breed B the other five alleles on loci 6-10 and mutated alleles on loci 1-5. No matter how you crossbreed those breeds and select the offspring, it will not be possible to unite these ten alleles in one individual, unless you get very lucky with recombination, which is unlikely. This is a descriptive example of course, but it is very likely that in many cases wildtype and domestic alleles are linked on the same chromosome. This could even be a problem for traditional "breeding-back" as it is executed by all modern projects. 

Nevertheless, let us ignore those practical obstacles for now and assume that "genetic selection" is feasible. Which animals would be needed in order to unite as much genetic material of the aurochs present in living bovines? A set of primitive European taurine breeds will not be enough in order to seize the maximum potential. Zebus have been shown to share wildtype alleles with the British aurochs whose genome was sequenced that taurine cattle have lost [1]. Therefore, zebus would have to be included in a "genetic selection" project. It is likely, or perhaps very likely, that there are also alleles which taurine cattle lost and are not preserved in zebus, therefore have been lost in cattle altogether. Some of them, however, could be shared by closely related wild bovines, such as the banteng, gaur, yak, or the two bison species. This would have to be tested. Probably also a wider range than just Southern European primitive breeds would be needed in order to seize the genetic potential of taurine cattle. What about Near Eastern cattle, or Asiatic taurine cattle such as the Turano-Mongolian group? It is not unlikely that they have wildtype gene material not found in in European taurine cattle. 

Thus, if one really is to carry out a project that tries to get as much genetic material from the aurochs as possible, not only European taurine cattle, but maybe also taurine cattle of other genetic groups, surely zebuine cattle and perhaps even related bovine species would have to be used. I still think such a project is not practically feasible, but it would be interesting "how far" such a project would get to approximate the aurochs. However, it might be a lot easier to recreate a genuine aurochs via CRISPR-Cas9. For my thoughts on what to do with a genetically recreated aurochs, go here. 

[1] Orlando et al.: The first aurochs genome reveals the breeding history of British and European cattle. 2015. 

Leptobos and the origin of Bos and Bison

In the most recent phylogenies based on mitochondrial DNA, Bos turns out to be paraphyletic. The yak is grouped as a sister taxon to Bison, and banteng and gaur form a clade that is sister to yak and bison [1,2]. The wisent is a sister taxon to cattle in this phylogeny, was has been interpreted as the result of hybridization. The most recent study, however, considers it more likely that this is the result of incomplete lineage sorting [1].  

Regarding the origin of Bos, there are two conflicting hypothesis. One that suggests an African origin, and one that suggests an Asiatic origin. Advocates of the "out of Africa" hypothesis suggest an origin from Pelorovis oldowayensis [3]. Pelorovis, however, is considered to be too different by other authors. They suggest an origin from Leptobos instead, which is described as more similar to Bos [4]. 

Leptobos comprises a group of fossil bovine species with very variable horns. Leptobos is also suggested to be the direct ancestor of Bison. And indeed the cranium of L. vallisarni bears striking resemblance to bison skulls, so that some authors list it as Bison vallisarni instead. Leptobos stenometopon, on the other hand, has a horn curvature that is reminiscent of that of aurochs, kouprey and yak. This horn curvature could either be basal to the Bos-Bison clade or evolved several times. The fact some species of Leptobos resemble Bos species while others resemble bison in cranial anatomy might imply that different species of Leptobos gave rise to the modern Bos clades (aurochs/cattle, the banteng-gaur and possible also kouprey clade) and bison. In this case, Leptobos would be a genus that includes the basalmost members of the Bos-Bison clade. This is only my personal speculation. More complete skeletal material would be needed in order to better resolve the paleontological evidence for the origin of the Bos and bison species. 

Leptobos etruscus - is Leptobos the ancestor of the Bos-Bison clade?

[1] Wang et al.: Incomplete lineage sorting rather than hybridization explains the inconsistent phylogeny of the wisent. 2018. 
[2] Verkaar et al.: Maternal and paternal lineages in cross-breeding bovine species. Has the wisent a hybrid origin? 2004. 

[3] Martinez-Navarro et al.: The Olduvai buffalo Pelorovis and the origin of Bos. 2007. 

[4] Tong et al.: New fossils of Bos primigenius (Artiodactyla, Mammalia) from Nihewan and Longhua of Hebei, China. 2014. 

A zebuine ancestry for Chianina?

Genetic studies have helped a great deal to understand the history of domestic cattle populations in recent years. 
For example, it has been resolved that many Southern European cattle breeds have influence from North African taurine cattle [1], which is not surprising considering that there were trade routes in ancient times. North African taurine cattle are genetically distinct from other taurine cattle, which is interpreted as the result of significant introgression of African aurochs [1]. Therefore, many Iberian and some Italian breeds might have African aurochs in their ancestry. For Chianina (and related breeds such as Romagnola, Marchigiana and others) in particular, zebuine influence has been detected as well [1]. This does not surprise me that much, as I have been suspecting that the white colour of Chianina (produced by at least two different alleles, on the Agouti and Dun locus) is actually inherited from zebus. Some zebu breeds have exactly the same white colour as Chianina, for example see the Nelore breed. Also, the face of Chianina looks slightly zebuine to me, as well as the fact that it lacks curly hair on the front head (which is typical for zebuine cattle but rare in taurine cattle). 

So Chianina is influenced by zebuine cattle. This might be used as an argument against the use of Chianina in "breeding-back" by those who want to use Maremmana instead for large size. However, Podolian cattle - such as Maremmana - are significantly influenced by zebuine cattle as well [2,3]. This also shows in the phenotype: I suspect that the upright horns, large dewlap and Agouti dilution of Podolian cattle are derived from zebuine cattle. 

But I think this is neither an argument against Chianina or Maremmana. Zebuine influence is simply not all that uncommon in taurine cattle, and unavoidable for "breeding-back", as many breeds needed for certain traits, such as size, have zebuine influence. 

As an interesting side note, it has been recognized that zebus share some wildtype alleles with the British aurochs whose genome was fully sequenced, while taurine cattle have other alleles on these loci [4]. So zebus do have some alleles in common with the European aurochs. 

[1] Decker et al.: Worldwide patterns of ancestry, divergence and admixture in domestic cattle. 2014. 

[2] Papachristou et al.: Genomic diversity and population structure of the indigenous Greek and Cypriot cattle. 2020. 

[3] Upadhyay et al.: Genetic origin, admixture and population history of aurochs (Bos primigenius) and primitive European cattle. 

[4] Orlando et al.: The first aurochs genome reveals the breeding history of British and European cattle. 2015.