sutton026

T he Caucasus mountains were home to another subspecies of wisent,  Bison  bonasus  caucasicus,  until was exterminated in the first half of the 20 th century (it is also considered a separate species by some authors). Nowadays, wisents have been reintroduced in the western Caucasus reserve, and this population is controversial for its special history. In this post I am going to explain why, have a look at the arguments against this population, why I consider it beneficial instead and what to do with it for the future.  First and most importantly it is to note that the modern wisent went through a severe genetic bottleneck event. All modern wisents descend from only 12 founder individuals and thus the genetic basis of the species today is extremely narrow. The consequences of this a considerable inbreeding depression affecting skeletal growth leading to skull asymmetry, deformation of the male gonads, increased rate of stillbirths, decreased female fertility and...

B ack in a 2013 post , I called Maronesa a “relict breed” from Portugal. Not because of an alleged isolated ancient origin, but for its flawlessly aurochs-like colour make-up, the well-expressed sexual dimorphism and the inwards-facing horn curvature.  Now there is a kind of quarrel on the English Wikipedia page regarding the origin of this draft breed. While enthusiasts of the breed claim a separate origin that is strongly influenced by local aurochs, others are convinced that it has its origins among other local breeds and is closely related or descends from Barrosa and Mirandesa. So here is my take-on to this subject based on literature references, old photos and the phenotype of Portuguese cattle breeds.  First off, Maronesa has traditionally been considered a crossbreed of Mirandesa and Barrosa because of historic evidence [3]. It has been considered a mix population until it was categorized as a separate breed in 1835[1]. A genetic study from 1998 found a genetic distanc...

T he previous three posts ( here , here , here , here  and here ) have explored the borders of “breeding-back”. I give a quick summary. The real differences between aurochs and cattle do not only concern size, coat colour and horns but actually the whole organism: its developmental biology, its endocrinology, its neurology, its behaviour, its morphology, its genome. And all those factors are interconnected and interact in a complicated way. It was probably selection on tameness alone that dramatically changed the organism and the typical traits of a domestic animal (“domestication syndrome”) was more of a by-product. Additionally to that, some new morphologic mutations and artificial selection on certain traits produced the typical domestic phenotype that we see in cattle. The involved number of loci are probably hundreds or more likely thousands. It is very likely that cattle are uniform for these key genes that are responsible for the typical domestic traits that are universal am...

E very once in a while I do new aurochs reconstructions. Each time I think I finally achieved a reconstruction where I can say "now that's what an aurochs looked like, perfect" I start noticing some imperfections afterwards, thinking "well, this and that detail should maybe be different". It is an interesting phenomenon, maybe I am too much of a perfectionist. I think that the overlap of all my reconstruction might present a good picture of what a living aurochs might have looked like.  Apart from that, the differences in the outcome of the reconstructions also reflects the individual variation within the species. For my most recent reconstructions, I once again choose the two Sassenberg skeletons, bull and cow. The Sassenberg bull, a cast of whose skeleton can be seen here  has extensive tooth wear and probably was an old specimen. The withers height of the skeleton is 165cm according to Frisch 2010, what means that in life it was probably 175cm tall at the wi...

T wo recent posts ( The real differences between aurochs and cattle and Is genetic breeding-back possible ) show the differences between wild and domestic, aurochs and cattle and also point out the limitations of “breeding-back”. Since the aurochs is extinct, it would be an interesting test for “breeding-back” to do exactly the same what we do with cattle (taking primitive individuals, crossbreed them and breed them selectively in order to approach the wildtype) but only with a species where the wildtype is still extant so that you can compare the outcome directly to it. Actually, this has been done already and the result is known as the Tamaskan dog. It is a dog breed that was created by crossing wolf-like dog breeds and selecting them towards a wolf-like appearance and the result is actually pretty good. Thus, the Tamaskan dog is a kind of “test” for “breeding-back” with cattle and therefore we are going to have a look at it today.  (Actually, five years ago I already did a post...

I n the post Cattle are modified designer aurochs I explained how “cattle” is just a term for an aurochs that has been modified by millennia of domesticative breeding.  I used Maronesa, Fleckvieh and Heck bulls as examples. Despite an overall similarity that Maronesa and Heck cattle bear to the aurochs, most of the differences between aurochs and cattle apply in both cases. For this post, I want to analyse the Lidia breed, Iberian fighting cattle, in the same way. In case you haven’t read both posts that I just linked here yet I would recommend to have a quick read through them before you continue with this post. The references for the claims below are provided in those articles.  Changes from aurochs to Lidia    Two comparably aurochs-like Lidia bulls on Wikimedia commons The most obvious change from aurochs to Lidia is size. Size is on the one hand probably influenced by endocrinology (as hypothyreodic rats demonstrate) but also by mutations on the dozens, h...