Tuesday, 28 February 2023

Is outbreeding the wisent necessary?

I did a couple of posts where I suggested cautious outbreeding for the wisent using its closest living relative, the American bison, in order to overcome a supposed inbreeding depression resulting from the extreme genetic bottleneck of the modern population (which descends from only 12 founding individuals). See 

- Over-purity as a danger for the wisent?

- What to do with the wisent in the Caucasus?

- Controlled hybridization for saving the wisent? 

Consequently, I used to regard the Caucasus population, which has been living in the wild for several decades now and has an American introgression of roughly 5%, as very valuable for the conservation of the species. It has been several years since I wrote these posts, and which this one, I want to give my current take-on to the question if outbreeding the wisent is actually necessary for its conservation. 

This question is sometimes intermingled with the controversy revolving its taxonomical status in relation to the American species. Some consider both forms subspecies of the same species because they are fully interfertile, i.e. they can produce hybrids that are fertile in both sexes, others prefer to retain the separate species status for both forms. I have no firm opinion on this, because I think having one is not useful as there is a) no clear definition of a species that works universally and that everyone agrees on and b) it is only intuitive that not all species are differentiated to the same extent because the time of separation between two given lineages may differ, the intensity of the selective pressure the lineages may experience may differ, the impact of mutations that appear in those lineages may differ (one mutation that has a drastic effect may prevent hybridization in otherwise very closely related lineages). Thus, I think having a firm opinion on if European and American bison are two distinct species or subspecies of one species and fighting over it is not very useful. Furthermore, moving back to the actual topic of this post, it is not really relevant for the question if American introgression should be utilized in the conservation of the wisent, as the taxonomical status of both forms does not make both lineages any more similar or dissimilar to each other. Taxonomy describes facts and does not create facts. 

In my posts linked above I describe detrimental consequences of inbreeding that can be found in the wisent. The fact that these consequences exist, however, does not tell us much about the frequency at which they appear and if they are a problem for the long-term wellbeing of the species. The status survey and conservation action plan for the wisent from 2004 describes the inbreeding depression in the wisent as “very small” [1]. Tokarska et al., who evaluate the genetic variability in the Bialowieza herd, even note the “absence of any signs of inbreeding depression”, although the low genetic diversity is seen as a potential threat as it implies low adaptability [2]. 

It is true that wisent populations may suffer from wisent-specific balanoposthitis and the species is particularly sensitive to foot and mouth disease, and introgression from American bison might (or might not) help to overcome this (although American bison are not immune to the latter disease either), but the average percentage of males in Bialowieza that have had balanoposthitis from 1980 to 2005 was only 6,5%, rarely reaching above 10% in some years [3]. 

What the wisent really needs in order to ensure the long-term prosperity of the species would be space for large populations (several thousands) to thrive and – very important – protection from poaching [1]. Larger populations, even if inbred, have a much higher chance of surviving than small, dispersed herds of only a few dozen individuals. If the population is large enough (the wisent conservation action plan from 2004 suggests numbers of up to 3000 individuals), the individuals that display negative consequences from inbreeding because they have a higher number of deleterious alleles would have less reproductive success than those that have fewer deleterious alleles. Eventually, natural selection in a population that only is large enough will lead to a relative increase of non-deleterious alleles and a decrease or even disappearance of deleterious alleles. 

A scenario in which outbreeding with their American relative would be beneficial is when there is a gene at which all or many wisents are homozygous for a deleterious allele that has a noticeably detrimental effect on the organism, and American bison have healthy alleles on this very gene, or if there were even several of such genes in which this is the case. In this scenario, it would certainly be beneficial to use American introgression in a separate studbook and using genetic tests in order to ensure that the hybrids only carry the healthy alleles on the gene(s) in question. But no such scenario has been reported yet. That means that further research on the genetic health of the wisent is necessary to determine if outbreeding would be useful and worth the effort at all, and it is perhaps questionable if that was the case if there was enough space for large populations of wisents to thrive. We should not forget that both bison types are the result of unique evolutionary processes on different continents, and full transparency in the form of a separate studbook would be a prerequisite for carrying out introgression. 

What to do with the Caucasus population that has roughly 5% of American introgression, then? I still think it is a very valuable population, for the very fact that several decades of natural selection followed the hybridization event in the 20th century. The genetic and phenotypic health of this population should be studied. For example, it should be examined if balanoposthitis is less frequent or even occurs at all in the Caucasus population. I think this population should be studied, and not exterminated, as suggested in the wisent conservation action plan from 2004 – considering that there is no continuous range that includes herds without American introgression the danger of contaminating the purity of other herds is low. And even if the herd merges with a pure herd, only the alleles advantageous for the survival of the population in that specific environment get to spread – there cannot be anything bad about that, from an evolutionary perspective. The original wisent form that was native there, B. bonasus caucasicus, has been hunted to extinction already anyway. Arguments that the wisents with American introgression are detrimental to the ecosystem or maladapted are very dubious, as I explain in the post “What to do with the wisent in the Caucasus?” linked above. 


All in all, I think that trying to establish large (several thousand individuals) populations of the wisent in the wild that are protected from poaching should have priority over the idea of outbreeding in order to conserve this species in the long run. If one wants to execute outbreeding, more research on the genetic health of the wisent should be done before that, in order to see if it will be effective in the first place. Studying the Caucasus population that already has American introgression would be relevant for this. 




[1] Pucek, Krasinski, Krasinska, Olech, Belousova: European bison – status survey and conservation action plan. 2004. 

[2] Tokarska et al.: Genetic variability in the European bison (Bison bonasus) population from Bialowieza forest over 50 years. 2009. 

[3] Krasinski & Krasinska: Der Wisent – Bison bonasus. Neue Brehm-Bücherei. 2008. 



Sunday, 26 February 2023

Portrait of a generic aurochs cow

For today, I have a quick little sketch of an aurochs cow that I painted with GIMP. It is not a reconstruction of a particular specimen, but is a portrait of a generic aurochs cow that aims to show all the traits typical for female European aurochs. 
So far, no "breeding-back" cow of any project looks like that. However, I think it is quite possible to achieve something that resembles this quite closely. Possible breed combinations suitable for this endeavour would be Sayaguesa, Lidia, Chianina/Maltese, Watussi and Maronesa, considering only the best representatives of the respective breeds. One has to keep in mind that "breeding-back" with cattle is a long-term project as they are a slowly reproducing species. A possible breeding scheme could be breeding an F2 of the combination F2 (Sayaguesa x (F2 Lidia x Chianina/Maltese)) x F2 (Sayaguesa (F2 Watussi x Maronesa)). That would take five generations, hence 10-15 years. That is a long time of course, but current breeding projects have been running for a similar time span for now and the results of such a lineage could be quite qualitative. It must be kept in mind that the scheme I just described is only one of very many ways of getting to the goal that is producing a lineage of cattle that resembles the European aurochs to the largest possible degree. 

Thursday, 2 February 2023

What a "breeding-back" zebu could look like

All current “breeding-back” projects focus on the European subspecies, but that one is not the only that left living, domesticated descendants. There probably was introgression into African taurine cattle from B. primigenius mauretanicus, and the Indian aurochs was domesticated as well, the results being called zebus. A “breeding-back” initiative for zebus would be very interesting, as they still exhibit some of the autapomorphies of the Indian aurochs. 

However, since the Indian aurochs, also called Narbada ox or as I also like to call it, wild zebu, is less well-documented than the European form, the breeding objectives for such a zebu “breeding-back” project would be less clear. I did a number of posts on the Indian aurochs, the most recent being this one. 

To sum up what the Indian aurochs most likely roughly looked like: 

- smaller than the European form, possibly between 150 and 160 cm withers height in bulls

- proportionally larger, slightly more upright and more wide-ranging horns 

- narrower skull with less prominent eye sockets 

- probably very similar postcranial anatomy, with long legs, short trunk and a shoulder hump (not to be confused with the fleshy indicine hump) 

- perhaps a slightly larger dewlap than the European aurochs 

- a colour possibly similar to that of the European aurochs, perhaps with some minor differences as zebu colours suggest

- very likely sexual dichromatism comparable to the European aurochs and Java banteng 

All of these traits can be achieved or approximated by breeding with less-derived zebu landraces. I would include: 

- some Deshi variants (wildtype colour, useful anatomy) 

- Kankrej (sometimes horns of a useful curvature and size, large-bodied) 

- Deoni (very short trunk and long legs, small udder and slender body) 

- Watussi (horn size and partly curvature)

This set of breeds can result in a zebu that looks more like what their wild ancestor looked like than many or all other zebus breeds. However, it would not yet seize the complete potential to mimic Bos primigenius namadicus as the horns would probably be more or less too upright, the zebus would still have an indicine hump which is unlikely to have been present in the Indian aurochs, they would have little to no sexual dichromatism as this trait is barely present in zebus. The solution to that is, in my opinion, to include: 

- Sayaguesa: for the overall aurochs-like morphology, for the lack of an indicine hump and the presence of a well-developed shoulder hump as in the aurochs 

- Java banteng: for the sexual dichromatism. Many cow-coloured zebus have a colour that is virtually identical to that of the Java banteng minus the white socks and buttocks (reddish-brown colour, dark brown dorsal stripe etc.), suggesting that female Indian aurochs had this colour. Of course it would be possible to include a taurine breed that reliably has sexual dichromatism such as Maronesa, but in these the cows are not nearly as lightly-coloured as in zebus and Java banteng. 

Some might think now that I am crazy suggesting a taurine breed and another species for “breeding-back” focusing on the Indian aurochs. But for once, I am not afraid of using less-derived zebu landraces for “breeding-back” focusing on the European aurochs, since they share some alleles with the European aurochs that taurine cattle have lost and contribute some phenotypically desired traits that taurine cattle do not have. So the reverse is legitimate to me as well, using a taurine landrace to acquire a trait that cannot be achieved with zebus alone, in this case, the lack of an indicine hump and the overall aurochs-like morphology. As for the banteng, I suggest using wild yaks and Java banteng for “breeding-back” focusing on the European subspecies, but only in very small doses and only in experimental herds, used very wisely with efficient selection (and not rampant hybridization in order to see what happens). The wild yak is unnecessary for a zebu project and possibly even counterproductive considering its climatic adaptions, so I’d only go with small doses of Java banteng to breed for the right colour dimorphism. I would backcross the hybrids as often as possible with “pure” zebus until the taurine and banteng influence is reduced to virtually nil genealogically, but always keeping those individuals that display the desired traits. 

I did a painting with GIMP what such a “breeding-back” zebu bull could look like, and this is the result: 

Overall, while the result would still be a domestic animal, it possibly resembles what we know of the Indian aurochs quite well on certain traits, and would be suitable to fill its ecologic niche in Southern Asia. 





Thursday, 26 January 2023

Is the domestication syndrome a myth?

In most if not all of my posts on domestication and dedomestication I mentioned the concept of the domestication syndrome that says that domestication works by the same mechanisms and has the same effects in any species that was domesticated. Domestic animals share certain traits, which are that eye-catching that it seems very intuitive that the domestication syndrome as such exists. Parts of my dedomestication hypothesis are based on the assumption that there is a domestication syndrome. However, the concept has been called into question in several works. 

The domestication syndrome is the assumption that all domestic animals, mammals in particular, share certain phenotypic traits, both behavioural and morphological. These include paedomorphy in behaviour and morphology, a reduced brain volume, reduced sexual dimorphism, piebald or spotted coat colour patterns, loss of seasonal adaptions, increased reproductive rate, earlier maturity and others. The hypothesis was expanded in publications discussing the findings of the famous Farm fox experiment, namely that artificial selection on tameness alone produced many of the typically domestic traits as a by-product, suggesting that there is a connecting mechanism working during domestication. You can read my post that I linked above for more detail and literature references on that. 


The validity of the Farm fox experiment as evidence for the domestication syndrome is called into question in some sources. For example, the alleged cranial shortening in the foxes selected on tameness is based on anecdotical evidence, it turned out that they are not distinguishable from wild foxes in cranial morphology [1]. A brain volume reduction has not been detected in selected foxes [1]. White spotting in the colour that has been said to be a by-product of the selection on tameness is also found in the control group and the foxes selected on increased aggression [2]. However, the white spotting is more common in the foxes selected on tameness than in the other groups [1]. Nevertheless, a spotted coat colour and a curved tail (the latter trait found in 10% of the foxes selected on tameness), is not associated with increased tameness in the individuals [1]. Lord et al. state that due to the limited population size of the starting population, it is possible that shifts in allele frequency were caused by “chance alone” [1], therefore morphological changes in the selected foxes do not necessarily have to be caused by selection on tameness according to the authors [1]. 

However, there seems to be a weak correlation between tame behaviour and white spotted coat colours in rats and foxes [3]. It has been found, interestingly, that there is no correlation between several physical characters considered symptoms of the domestication syndrome (f.e. floppy ears, spotted coat colours) among each other, and with behaviour among dogs [4]. This seems to be contradictory to what would be expected by a very strict application of the domestication syndrome hypothesis. Also, mutations causing piebald coat colour patterns also appear in wild animals. It is not all that rare in several deer species, for example moose in North America: 

If the piebald coat colour patterns in domestic animals are strongly connected to tameness, it would have to be expected that these moose are also less fearful towards humans than their “normally” coloured conspecifics. This assumption would have to be tested. 

There is a paper by Lord et al. that calls brain volume reduction as a consequence of domestication into question [5]. However, the reduction of brain volume is well-documented for many domesticated species [6], and has recently also been found to be the case in cattle compared to the aurochs [7]. Another problem is that the paper by Lord et al. adopts the premature conclusion by Gaunitz et al. 2018 that the Przewalski’s horse is feral and “not wild in any sense” [6], while they consider the feral European mouflon a wild animal to compare sheep against [6]. So they consider a wild animal feral and a feral animal wild, what is a bit of a problem in the argumentation. 

A major component of the hypothesis that selection on behaviour results in alterations of physical appearance is the proposal that neural crest cell genes are affected by selection on tameness [2,8]. The neural crest is a precursor of many cell types in vertebrates, pigment cells among them. The hypothesis says that if the genes of neural crest cells are affected by selection on tameness, the migration of the precursors of pigment cells is distorted, causing irregular unpigmented areas on the body, resulting in the piebald coat colour that is seen in many domestic animals. A very recent paper compared neural crest genes of domestic animals of several species and compared it to the respective wildtypes or animals related to the wildtype (bison were used to compare with domestic cattle, for example). The result was that evidence for positive selection on neural crest genes was found in nearly all cases [8], providing support for the hypothesis that alterations of the genes of the neural crest played a role in domestication of the species that have been domesticated [8]. Interestingly, in the Farm fox experiment it was noted that crossing two white-marked foxes would occasionally produce offspring that held their head askew [1]. I think it is possible that the allele(s) producing these white markings are connected to factors detrimental for the development of the nervous system, what would support the neural crest hypothesis, although other explanations are plausible as well (f.e. asymmetric development of musculature, abnormities in the vestibular system) – that phenomenon deserves further investigation in my opinion. 

Domestication goes hand in hand with an increase of deleterious alleles as a result of mutation accumulation since natural selection plays no or only a minor role in domesticates. This phenomenon is described as the “costs of domestication” [9]. Mutation accumulation might be an alternative explanation for why piebald coat colour patterns are found in all domesticated species. Rather than being connected to behavioural aspects that get selected for during domestication, it is possible that these piebald patterns showed up due to spontaneous mutations that also appear in wild populations, and humans tended to favour these deviant colour variants in their breeding regime. In fact, piebald patterns are only one type of novel colours that appear in domestic populations. Many domesticated species show melanism (found in cattle, dogs, horses, cats and others), erythricism, leucism and albinism as much as completely novel coat colours, yet nobody suggested that these pigment modifications are a common consequence of domestication and possibly connected to behavioural traits (with the exception of melanism, which has been linked to increased aggression in the past). Piebald patterns even exist in “domesticated” fish such as the goldfish, and as far as I know goldfish were never particularly selected for tameness. The fact that white markings are more common in the foxes selected on tameness than in the other lineages can also be due to genetic drift or the loci regulating those markings being coincidentally genetically linked with those regulating tameness on the same chromosome. Therefore, white spots do not necessarily have to be a consequence of behavioural modifications during domestication.

While white spotted patterns are not a good example for the connection between physical characteristics and behaviour and the role of this possible connection in domestication, I would not give up that hypothesis. We should not forget that paedomorphy and a reduced brain volume are very common among domestic animals, and that changes in hormone productions likely played a role in domestication. Thyroid hormones have a major role in postnatal growth, pigmentation, brain development, adrenal gland function and development of the gonads [10]. Selection on tameness is, to a certain degree, selection on paedomorphic behaviour as the fear response of juvenile mammals is much less intense than that of fully grown ones. Therefore, selection on tameness might have influenced the overall development, causing the expression of hormones relevant in adulthood to be delayed. This would lead to an overall paedomorphy because it would affect thyroid hormones, among others (corticosteroids might play a role as well). If the consequence is a shortage in thyroid production, this would have a dramatic influence on the morphology of the animals. For example, hypothyroidic rats are smaller, have a shorter snout and floppy ears – they have paedomorphic, domestic characters. Hypothyroidism is also known to cause cretinism in humans, which includes symptoms such as shortened extremities, reduced body size and lowered cognitive abilities. This is what we see in many domestic animals. I also think that hormonal changes are responsible for the brain volume reduction, perhaps even the thyroid hormones, rather than the fact that a domestic life is less cognitively demanding than a life in the wild, what is usually offered as explanation for the smaller brains of domesticates. We should also not forget that the neural crest genes of domesticates show signs of positive selection as outlined above, although pleiotropic effects leading to a change in physical appearance have not been proven directly yet. 

I think the domestication syndrome concept would be invalidated if there was a domesticated species that is completely devoid of any traits that are considered symptoms of the domestication syndrome such as paedomorphy, reduced brain volume and others, yet still behaves completely domestic, i.e. has a very moderate fear response, reduced aggression and increased tameness compared to its wildtype, trainability and agreeableness. Sixteen mammal species have been domesticated, yet there is no such case. This indicates to me that the domestication syndrome is a valid concept, although piebald colour patterns possibly have to be excluded from the list of symptoms considering the weak to absent correlation between them and tameness. 




[1] Lord et al.: The history of Farm foxes undermines the animal domestication syndrome. 2019. 

[2] Wilkins: A striking example of developmental bias in an evolutionary process: the “domestication syndrome”. 2019 

[3] Wilkins et al.: The “domestication syndrome” in mammals: A unified explanation based on neural crest cell behaviour and genetics. 2014

[4] Wheat et al.: Morphology does not covary with predicted behavioral correlations of the domestication syndrome in dogs. 2020. 

[5] Lord et al.: Brain size does not rescue domestication syndrome. 2020. 

[6] Balcarcel et al.: The mammalian brain under domestication: discovering patterns after a century of old and new analyses. 2021. 

[7] Balcarcel et al.: Intensive human contact correlates with smaller brains: differential brain size reduction in cattle types. 2021. 

[8] Rubio: Neural crest cell genes and the domestication syndrome: A comparative analysis of selection. 2022. 

[9] Moyers et al: Genetic costs of domestication and improvement. 2017. 

[10] Dobney & Larson: Genetics and animal domestication: new windows on an elusive process. 2005

Thursday, 19 January 2023

Extinct megafauna that could be revived using genome editing

Humans wiped out countless species of animals. Some of those species, particularly those that died out comparably recently, might actually be retrievable. Usually, cloning comes to mind when talking about reviving extinct animals. However, somatic nucleus transfer for reproductive cloning requires an intact cell and not just the DNA of the animal, which is why it is not available for most species wiped out by man. However, there are a few megafaunal species that have been wiped off from which we have at least one and in some cases several complete genomes. If there is a still extant species that is closely related and would make a suitable surrogate, it would be possible to exchange the alleles specific for species A with those for species B and thus creating a viable cell with the genome of the extinct species in question with genome editing. This limits the number of extinct animals that could be revived. For example, I would imagine it to be pretty difficult if not impossible for a species like the thylacine, which has been evolutionary separated for 30 million years from its closest living relatives. In some cases, it could be easy and much less effortful because of the lower number of genes that differ and the suitability of the surrogate because the animal has a very close living relative. In this post, I present a number of megafaunal species from which full genomes either have been acquired or at least could potentially be acquired and which have a more or less closely related relative that can be used for genome editing and as a surrogate. The mitochondrial DNA of the resulting animal would be that of the donor cell, which would be from the related species. However, as mitochondrial genes are highly conserved among mammals this would not have much of an influence. Using closely related species also has the advantage that the behaviour will be rather similar, especially among the large herbivore species that I am going to list. This makes the rearing by a surrogate mother and socialization of the result less problematic or maybe not even an issue at all. 

I see reviving an extinct animal that has been wiped out by man as a contribution to species conservation just as breeding an endangered species or subspecies. One might ask, particularly in the case of wiped-out subspecies, why doing that at all if there are suitable ecological proxies. Occasionally some even question the need to conserve endangered subspecies such as the Northern White rhino because their conspecifics from other subspecies would function ecologically the same or very similar. Personally, I cannot relate to that mindset. Conservation is about preserving biodiversity and the preservation of evolutionary more or less distinct subspecies is a vital part of that. The same goes for reviving extinct species or subspecies – it would greatly increase the biodiversity again, after it has been depleted by man when the species or subspecies was wiped out. 


Bubal hartebeest, Alcelaphus buselaphus  

This animal is sometimes also considered a subspecies, but that question is merely taxonomical and not relevant for “de-extincting” the animal. In any case, other members of Alcelaphus could be used for genome editing and as a surrogate. Many individuals must have been preserved as trophies, and it is potentially possible to acquire full nuclear genomes from them. 


Bluebuck, Hippotragus leucophaeus  

Other members of Hippotragus could be used as a surrogate and for genome editing. It can be tried to acquire a fully nuclear genome from taxidermies.  


European aurochs, Bos primigenius primigenius

One full nuclear genome has been resolved in 2015 from a well-preserved Neolithic bone. Considering the richness of recent aurochs material, it could be possible to obtain quite a few more complete genomes. And there is a very close living relative, modern cattle. The number of genes that would have to be exchanged would probably be lower than in most of the other cases I am listing here, and also the surrogate and the procedure of implanting an embryo would be completely unproblematic. And considering the similarities in behaviour between cattle and aurochs, socialization will not be problematic either. For these reasons, I consider the aurochs one of the most realistic candidates for a revival through genome editing. Even if the resolved genome remains the only one to be fully resolved, one revived aurochs individual still can be outbred using aurochs-like cattle. I wrote a post on that a few years ago. 


Several types of wild horses 

There are well-preserved mummies of Siberian wild horses, Equus caballus lenensis, and one of the Yukon wild horse, Equus caballus lambei, so it could be possible to obtain fully resolved nuclear genomes from that. A domestic horse could be used for genome editing and as a surrogate. Even if only one genome can be obtained, the revived horses can be outbred with Przewalski’s horses and/or robust landraces in the same manner as I suggested for revived aurochs. 


Kouprey, Bos sauveli  

Numerous kouprey specimen have been preserved as trophies and one skin. It could be possible to obtain full nuclear genomes from that very recent material. The closest living relative is the Cambodian banteng which hybridized with the kouprey in the past. It can be used for genome editing, as a surrogate and even for outbreeding if necessary. 


Quagga, Equus quagga quagga  

The quagga is not and cannot be bred-back from extinction with living Plains zebras, which is why it would be desirable to try to acquire full genomes from the numerous preserved skins and the few skeletal material that is preserved of this zebra. The zebras of the Quagga Project can be used for genome editing, as a surrogate and outbreeding if necessary. 


Pyrenean ibex, Capra pyrenaica pyrenaica  

This is the only extinct animal that has been cloned so far, unfortunately the clone died shortly after birth. Genome editing with individuals from other subspecies of Capra pyrenaica could be more successful, they can be used as surrogates and for outbreeding. 


Steppe bison, Bos (Bison) priscus  

There are plentiful of remains from steppe bison, including soft tissue. Perhaps it would be possible to obtain full nuclear genomes from that. Needless to say, that still existing bison, be it European or American, can be used for genome editing, as a surrogate and outbreeding. 


? Woolly mammoth, Mammuthus primigenius  

Currently, there is no de-extinction project in the strict sense focusing on the woolly mammoth. There is the attempt to create a “mammophant” by introducing mammoth alleles for certain traits into the genome of an Asian elephant, what is not what I would consider de-extinction in the strict sense. If doing that is possible, it might also be possible even if more effortful, to exchange all alleles of genes where Asian elephant and woolly mammoth differ. However, since implanting an embryo into an elephant is very complicated, and those who want to create plan to use an artificial womb, a technique which does not exist hitherto, I wonder if it is feasible to recreate the woolly mammoth for practical reasons. 


Caucasian Wisent, Bos (Bison) bonasus caucasicus  

Several skins and trophies of this wiped-out subspecies (or species or variety, there is no consensus on its taxonomic status) exist, so it could be possible to obtain full nuclear genomes from it. European bison of the Lowland-Caucasus line, which partly descend from the last Caucasian wisent bull, could be used for genome editing, as a surrogate and for outbreeding. Obtaining genomes from remains of wisent prior to the bottleneck in the 20th century could also help to greatly increase the very limited genetic diversity of this endangered bovine. 


Cave lion, Panthera spelaea  

Several very well-preserved pubs of this feline have been found. It might be possible to acquire full nuclear genomes from that, and the closely related actual lion would be suitable for genome editing and as a surrogate. 


Schomburgk’s deer, Rucervus schomburgki  

Some remains of this deer species exist, a sister species from the Rucervus clade could be used for genome editing and as a surrogate. 


Japanese sea lion, Zalophus japonicus

There are taxidermied specimens of this sea lion, related species of the Zalophus clade can be used for genome editing, as a surrogate and possibly outbreeding if necessary. 


Caribbean monk seal, Neomonachus tropicalis

There should be some remains of this recently extinct species, the related Hawaiian monk seal can be used for genome editing, as a surrogate and possibly outbreeding if necessary. 


One common objection against the revival of extinct animals is “one individual is not enough to build a population”. Apart from the fact that even one individual could tell us a lot about the extinct animal species/subspecies, it could be possible to get several genomes of those recently extinct species. Getting the full genome of five or ten individuals from different regions and times would probably enable to get a genetic diversity comparable to that of the modern wisent population, which descends from only twelve founding individuals from the same population. Some wisent individuals show inbreeding-related problems, but not to the extent that it threatens the survival of the species. An even more extreme example would be the Mauritius kestrel. Apart from that, related species/subspecies can always be used for outbreeding to add genetic diversity. Hybridization among related species with neighboring or overlapping distributions is very common in the animal kingdom. 


Sunday, 15 January 2023

The colour of Indian aurochs cows

We know nothing about the colour of the Indian aurochs with certainty, except for the fact that it must have had the E+ allele on the Extension locus, because the majority of zebus have it and it is also found in taurine cattle, suggesting that it was already present in the common ancestor of the primigenius and namadicus lineages. That means namadicus must have had the colour that has both phaeomelanin and eumelanin (red and black pigment), dispersed in some pattern across the pelage, a white muzzle ring and testosterone-dependent eumelanisation. Very likely sexual dichromatism was present, i.e. that bulls and cows had different colours. Some zebu breeds have retained a certain degree of sexual dichromatism, with the bulls being slightly darker than the cows. The colour of the cows is in the focus of this post. 

Many zebu cows that have the production of phaeomelanin enabled (the mutation disabling the production of red pigment is quite common among zebus and perhaps originated in that lineage) are almost homogeneously reddish-orangish-brown, with a dark brown dorsal stripe (that is not always present), lightly coloured rings around the eye and a lightly coloured area on the ventral side of the trunk and the inner side of the limbs. Black or very dark areas are (almost) absent. A colour consisting of a reddish-brown base colour with a dark dorsal stripe is sometimes also found in taurine cows, albeit rarely. It is much more common in zebu cows. The only black or very dark areas in zebus having that colour are, if present, along the anterior side of the forequarters, either down to the carpals or to the toes. I consider it quite likely that this is the original colour of female Indian aurochs cows and it can be seen in breeds like Red Kangayam. 

The reason for my assumption is that female Java banteng have a very, very similar colour. They are orangish-reddish-brown, with a dark dorsal stripe, lightly coloured areas on the inner side of the limbs and the ventral side of the trunk, they even have the dark areas on the forelimb, except for the part that is completely devoid of pigments. In fact, if those white “socks” and buttocks were not there, the colour would be almost identical. I see two possible explanations for that similarity: a) the common ancestor of both species had this colour and it is the ancestral trait, thus was also present in the Indian aurochs b) introgression from banteng into the zebu after domestication. As for the latter possibility, the introgression of banteng or their domesticated form Bali cattle is documented for some lineages of zebus. But I consider it less likely that this is the reason for the similarity in coat colour as in this case this colour would not be found in taurine cattle too, which it is, albeit rarely. Also, Red Kangayam are found in Southern India, where banteng introgression is less likely for geographic reasons. This makes the assumption that it is inherited from a common ancestor more likely, since such a close similarity in more or less closely related species is probably not a coincidence. If this colour was already present in the common ancestor of the Java banteng and the zebu, it is the most parsimonious assumption that it was present already in the Indian aurochs. That colour is in fact not all too special. Wildtype coloured calves in taurine and indicine cattle are usually reddish brown with a dark dorsal stripe, the cows retaining this dark dorsal stripe and having almost no black or dark brown areas just means that the process of growing what is the adult coat colour in bulls is stopped earlier than in European aurochs cows, which often had black heads, necks and legs or were even black with a red colour saddle, as cave paintings show. 

However, this colour being the result of banteng introgression into zebus after domestication cannot be ruled out completely, and in the lack of artistic depictions showing the Indian aurochs and the fact that female zebu appear in a wide variety of colours we can only guess what its colour was like. I think the colour shown by the Red Kangayam is a very plausible one for namadicus cows, but this has to remain a speculation, as long as we do not have any direct evidence of the coat colour of the Indian aurochs. 


Monday, 9 January 2023

Are domestic cattle truly smaller than the aurochs?

The question in the headline of this post will immediately be answered with “yes, obviously” by most people, which is understandable as the European aurochs is known for being a very large bovine and the size reduction is one of the most noticeable consequences of domestication in cattle. However, there is one aspect that should be considered. 

It starts with how to define body size. In mammals, one of the most widely used parameter of body size is the withers height. Going by this factor, it is obvious that the aurochs was much larger than most domestic cattle – very large breeds like Chianina or Bhagnari being the exception. Go here for my post on how large the largest aurochs might have been.

When naming the largest living land animal, most people will say it is the African elephant. This is because it is the heaviest terrestrial animal. But going by height, it would be giraffes, and going by length, the reticulated python would be the second-largest terrestrial animal on earth. Yet, those species are rarely considered the largest terrestrial animals. So, is mass the most important body size parameter? It is certainly an objective one, as it is almost independent of the morphology and bauplan of the animals (with the exception of birds which have an air sac system and pneumatized bones, which is why their bodies have a lower density than those of other terrestrial animals). If we go only by mass, let’s examinate if cattle are truly smaller than aurochs. 

One problem is that we do not know the exact weight of aurochs. No aurochs were weighted, so we can only guess by using extant wild bovines as a comparison. Since the males are larger than the females in bovines, I only refer to the mass of males in this post. Perhaps the weight of the aurochs was somewhere in the range of banteng, wisent and wild yaks, which would be between 700 and 1000 kg. Wild yaks have a slightly more elongated and more robust morphology than the aurochs had, but have a similar height compared to the largest aurochs (which is roughly 2 metres) and their weight is around 1000 kg. While yaks are built slightly more massive than aurochs, they have a higher shoulder hump, what influences the withers height. So it could in sum be that a 200 cm tall aurochs was roughly the same weight as a 200 cm wild yak. That would mean that a 160 cm aurochs had only about 510 kg. The wisent has similar proportions and a roughly similar build. The record for wisent height is 188 cm, for the weight it is 840 kg in wild-living animals. That means a 2 m wisent would be 1011 kg and a 160 cm wisent would be around 500 kg. Banteng reach up to 190 cm and 900 kg weight, which would be 529 kg in a 160 cm banteng. Since all those three bovines result in a similar weight range, maybe it is reasonable to assume a weight of around 500 kg for a 160 cm aurochs, and 1000 kg and slightly above for a 200 cm aurochs. Keep in mind that weight increases with x3 while height only with x. Those are only very rough estimates, and the weight would also depend on the individual condition of the animal and the season. 

What is interesting now is that many domestic bulls surpass the possible weight of the largest aurochs. Bulls with a weight of over 1000kg are actually not a rarity in breeds of a medium height. For comparison, the Taurus bull Lucio had a withers height of 165 cm and a weight of 1400 kg. A 165 cm tall aurochs bull would, if the estimation above is correct, weigh around 500 kg. So the Taurus bull has more than twice the mass of an aurochs with the same height. That is due to the different morphology: domestic cattle mostly have shorter legs and a longer trunk, plus a smaller hump as much as a way bulkier trunk, especially the intestines are enlarged. This results in a higher weight relative to the withers height.  

Lucio the Taurus bull (Sayaguesa x Heck)

The morphology of cattle drastically changed during domestication: the legs became shorter, the trunk longer, the intestines larger, the head smaller, the hump smaller et cetera. This led to a dramatic height decrease, while the mass was not that much affected. Surely there are dwarf cattle breeds that are lighter in weight than the aurochs probably was, especially during the Bronze age there were tiny cattle that were about the size of a sheep. But as far as the average modern day cattle body size is concerned, cattle lost height during domestication but not necessarily mass. In some cases, mass was even gained compared to the aurochs. 

So, if mass would be the only parameter for body size, then most domestic cattle are not necessarily smaller than the aurochs, it is their morphology that changed dramatically. 

Tuesday, 3 January 2023

The dingo: a post-domestic wild animal?

Long-term readers of my blog will be familiar with my dedomestication hypothesis that I proposed in the dedomestication series. The term dedomestication is not very established in scientific literature yet, but there can be now doubt that natural selection will change domestic animals that have returned into the wild. This evolutionary process would result in what I call a post-domestic wildtype, opposed to a predomestic wildtype. This post-domestic wildtype would be just as wild as any other wild animal, with the difference that it descends from a domestic population. 

I proposed that this post-domestic wildtype is not necessarily a revert to the original predomestic wildtype, but that it depends on the selective pressures in the respective environment, genetic drift and also that novel traits can be beneficial, especially in a new environment. As I write in my dedomestication series, the hypothesis has empirical problems. For once, feral domestic animals are understudied in terms of possible evolutionary changes they experience. And moreover, there are hardly any feral domestic populations that have been living in the wild under natural selection for a considerable time span sufficient for evolutionary changes to become visible and at the same time reproductively isolated from backcrossing with wild or domestic animals. For example, feral pigs in North America (razorbacks) sometimes greatly resemble the Eurasian wild boar, what would endorse one of the main proposals of the dedomestication hypothesis (namely that wildtype traits tend to have a higher evolutionary fitness and thus the feral population starts to resemble the original wildtype on adaptive traits). The problem is, however, that these feral pigs often hybridized with wild boar that have been introduced there as well, what explains the resemblance between the two. 

Nevertheless, I see two possible candidates for a post-domestic wildtype because of a considerable time span they have been reproductively isolated and exposed to natural selection: the dingo and the European mufflon. This post is going to focus on the dingo. But first of all, it is essential to define which criteria an animal would have to fit if it was to be considered a post-domestic wildtype. 


A definition of the post-domestic wildtype


The most abstract definition of a post-domestic wild animal would be that its biology is entirely shaped by natural selection and not artificial selection. In detail, this would mean: 

- It is devoid of typical signs of domestication: paedomorphy in behaviour and morphology, earlier maturity, loss of seasonal adaptions, white spotted patterns in the colour or other detrimental colour mutations, reduced brain volume, reduced sexual dimorphism

- It is adapted to the biotic and abiotic factors of its environment 

- It is more or less homogeneous in its biology, especially regarding adaptive characters 

The exact time span of how long the animal has been subject to natural selection is technically of limited relevance, because the speed at which evolutionary changes become evident depends on how genetically diverse the starting gene pool is – this is known as Fisher’s fundamental theorem and it describes that changes in allele frequency occur faster in a very diverse population compared to one that is genetically homogeneous.


Is the dingo a dog at all and does it have domestic ancestry? 


A question which has to be investigated before is if it is true at all that the dingo has a domestic ancestry and if it is a dog at all. That question is relevant as there are some sources questioning the status of the dingo as a dog and prefer to regard it as a separate wild canid species that was never domesticated like coyotes and golden jackals. 

This idea, however, seems to be contradicted by the genetic evidence. Jackson et al. 2019 have reviewed several phylogenies based on genetic analyses and all of them have the dingo placed within the phylogenetic tree of the dog [1]. This strongly implies that the ancestors of the dingo were domestic dogs. One recent study from 2022 had the dingo as a sister group to all other dog breeds examined, but the number of dog breeds used was only six [2], therefore very low considering that there are hundreds of dog breeds. It was found that the dingo has only one copy of the AMY2B gene, which is multiplied in other dog breeds as an adaption to starch-rich diet [2]. That is, however, not an argument in favour of the idea that the dingo is a never domesticated wild canid, it just means that the duplication of the gene did not occur right at the beginning of dog domestication so that there are breeds that do not have it. That would be like claiming Sayaguesa cannot be domestic because it has the E+ allele, which is wildtype. The dog breeds that group with the dingo are, among others, the Chow Chow, the Akita, the Basenji and Indonesian and various Southeast Asian dogs [1,3]. Half of the dingoes tested in one study have the A29 mitochondrial haplotype (which is considered ancestral to all the other mitochondrial dingo haplotypes), which is also found in East Asian, Southeast Asian and American dogs as well as the New Guinea singing dog [4]. So from a genetic perspective, there can be no question that the dingo is a dog and shares domestic ancestors with other dogs. 

It is also morphological evidence that contradicts the idea that the dingo is a distinct, never domesticated wild canid species. Dingoes do have vestiges of domestication, including typically domestic traits such as a brain volume reduced by 30% compared to the grey wolf [5], reduced mimics and less social differentiation compared to the grey wolf [5,6], curly tails in some individuals [7] and cranial paedomorphy [8] and the males are able to reproduce all the year round [7]. Moreover, some dingoes have clearly domestic coat colour variants, such as brindle or white-spotted or piebald patterns. All these traits strongly suggest that the dingo is a dog, sharing domestic ancestors with other dog breeds. 

Also the behaviour of the dingo demonstrates that it is a dog – dingoes are sometimes kept as pet dogs, and already the Australian aboriginal people kept dingoes [9]. Alfred Brehm in Brehm’s Tierleben reported that there were dingoes kept as pet dogs and were used to protect livestock. Also, ethologist Eberhart Trumler studied dingoes kept as pet dogs and reported that they can even be made house-trained. Keeping a wild canine, be it a wolf, a coyote or jackal, as a pet dog this way would be impossible. 

Therefore, putting everything together, I think there is no reason to not assume that the dingo is a dog and shares domestic ancestors with other dog breeds. 


Does the dingo fit the definition of post-domestic? Is it wild or feral? 


My definition of post-domestic can be seen above, it has three key points. Without question the dingo is adapted to its Australian environment, it can make use of various food sources and it is adapted to the climate as the wide geographic range on the continent demonstrates. Concerning its morphology, the dingo seems to be uniform like a wild animal. Concerning its colours, they are more variable than what is commonly expected. A 2021 study found that because of the variation in the dingo’s coat colour, this parameter cannot be used to discern pure dingoes from hybrids with other, later arrived feral dogs [10]. Wild animals are usually – usually, not always – comparably uniform in colour across the species and the dingo coat colour variation is obviously a vestige of domestication. However, if the domestic coat colour variants found in the dingo (I consider all of the colours found in the dingo domestic, i.e. they arose after domestication, as none of them are the wildtype colours shared by wolves, the ancestors of dogs) turn out to be adaptive in the new environment they have been introduced to (Australia), they cannot be used as an argument against a possible wild status. If a novel trait that arose during domestication is adaptive in a new environment and becomes fixed, it would actually be in line with my dedomestication hypothesis. I never proposed that a feral domestic animal would fully revert to the original wildtype under natural selection, because some novel traits can be adaptive especially when the population lives in a new environment that is different from that of the original wildtype. In Australia, the colour of the dingo is likely better camouflage than that of the wolf in Asia where the dog was domesticated. Therefore, the colour of the dingo is likely adaptive. Perhaps some more millennia of dedomestication will eventually lead to a uniform colour, via stabilizing selection and genetic drift. Therefore, if a possible post-domestic animal has retained novel traits that arose during domestication, it still can fit the criteria for being a post-domestic wild animal as long as these novel traits are either adaptive or evolutionary neutral. But the dingo also has other remnant traits of its domestic ancestry as outlined above, some of which are part of the universal “domestication syndrome” and possibly maladaptive, including the reduced brain volume, cranial paedomorphy and curly tails in some individuals. Also, the fact that dingo males are able to reproduce all year round shows that they have not yet fully redeveloped a seasonal reproduction circle. Moreover, the fact that dingoes can be used and trained as pet dogs shows that the neurologic-endocrinologic modifications that turned dogs into domestic animals are still present in the dingo, and that it has not yet lost the potential to develop domestic behaviour. To me, this suggests that the dingo should not be considered a post-domestic wild animal. 

It is problematic, however, to draw a distinctive line between feral and post-domestic wild. Rather it should be regarded as a continuum, as a spectrum. The dingo definitely is on this spectrum, but in my opinion still closer to feral than to post-domestic wild. Interestingly, there also seems to be a continuum from other basal dogs to the dingo, as Southeast Asian pariah dogs, Borneo dogs, the Korean Jindu and the American Carolina dog are phenotypically very similar to dingoes. All of them, including the dingo, can be kept as pets. 


An upcoming post is going to focus on the European mufflon as a post-domestic wild animal candidate.




[1] Jackson et al.: The Dogma of Dingoes – Taxonomic status of the dingo: A reply to Smith et al.. 2019.

[2] Field et al.: The Australian dingo is an early offshoot of modern breed dogs. 2022.

[3] Larson et al.: Rethinking dog domestication by integrating genetics, archeology, and biogeography. 2012. 

[4] Savolainen et al.: A detailed picture of the origin of the Australian dingo, obtained from the study of mitochondrial DNA. 2004. 

[5] Hemmer: Domestikation, Verarmung der Merkwelt. 1983 

[6] Trumler: Ein Hund wird geboren: der Ratgeber für den Hundefreund. 1982. 

[7] Zimen: Der Hund – Abstammung – Verhalten – Mensch und Hund. 1988. 

[8] Smith et al.: Brain size/body weight in the dingo (Canis dingo): comparisons with domestic and wild canids. 2017. 

[9] Roland Breckwoldt: The dingo: still a very elegant animal. In: A symposium on the dingo. 2001. 

[10] Cairns et al.: Pelage variation in dingoes across southeastern Australia: implications for conservation and management. 2021. 


Friday, 30 December 2022

How aggressive was the aurochs?

As my readers will know, many of my blog posts on the aurochs focus on aspects of its morphology or appearance, because that is what we know most about. But I also made posts covering social behaviour patterns, like this one. Today I want to cover a behavioural aspect of the aurochs that I am sometimes asked about: its aggressiveness. More precisely, its aggressiveness towards humans. Was the aurochs an aggressive animal towards humans, or was it gentle and docile? 

Regarding the aggression of the animal, we have to differentiate between intraspecific aggression, aggression towards other animals (predators in particular), and aggression towards humans. That is important because domestication drastically changed the latter factor, while the other two factors seem to be somewhat independent from it. Cattle that are very agreeable and docile towards humans still can become rather aggressive against opponents in intraspecific combat or towards possible predators. The question how aggressive the aurochs was is also important for “breeding-back” as it raises the question what kind of behaviour the cattle need in order to survive in nature, or to be aurochs-like, and what to expect from dedomesticated cattle living in the wild. 


Historic evidence on the behaviour of the aurochs towards people


The most famous notion on the behaviour of the aurochs is in Caesar’s Commentarii de bello gallico, writing that aurochs “will spare neither humans nor animals at sight”. Caesar also wrote that aurochs never get used to humans, even if raised as calves. Also, Anton Schneeberger who visited the last Polish aurochs in Jaktorow wrote that aurochs will get very hot-tempered when challenged. Andrea Swiecicki reported from the 16th century that aurochs will get very aggressive when being tormented and attack humans and horses, throwing them in the air with their horns [1]. Schneeberger further writes that aurochs are not afraid of people and will not run away if they stand in the way of the humans. As the Jaktorow herd was managed by humans and encountered people on a regular basis, it is possible that they were tamed to some degree [1]. These are the only general notions on the behaviour of aurochs towards people that have been preserved, at least as far as I know.

Caesar’s notion can be interpreted in a way that aurochs were generally aggressive animals, but Schneeberger’s and Swiecicki’s seem to be more differentiated, stating that they can become very aggressive when challenged or being hunted. Caesar’s impression that the aurochs will not spare any living being might come from the behaviour of the bovine in situations of threat. If one knows the animal only in the context of hunting it, one might assume it is generally a very dangerous animal. Schneeberger’s report clearly states that aurochs would not attack without a reason whenever they encounter a human, in fact he writes that one could easily approach it. If the aurochs at Jaktorow were indeed tamed to some degree, this could imply that the behaviour of aurochs towards humans was plastic and partly depended on socialization. However, Caesar’s notion that they never get used to humans even when raised as calves indicates that there were genetic limits to this. This is likely, as the difference in behaviour between domestic and wild animals is due to genetic differences to a certain degree. Curiously, Vergilius mentions that in the Po River area in Northern Italy aurochs were caught and tamed to be used as draft animals, in the lack of domestic oxen [1]. Either it was indeed possible to use grown, wild-caught aurochs for draft work or Vergilius was misinformed. It is even possible that these animals were not aurochs but feral cattle living in the region. Personally, I cannot imagine that it would be possible to use an undomesticated wild bovine for draft work, even if they were tamed to some degree. I think Caesar’s notion is more credible than that of Vergilius, both authors were basing themselves on second-hand information. 


The behaviour of domestic cattle 


For the social behaviour of the aurochs, cattle living under natural circumstances are a pretty good model. What we know of the social behaviour of the aurochs is congruent with that of cattle, and since domestication likely did not affect the social behaviour patterns of cattle, all the other aspects of their social behaviour are likely shared between aurochs and domestic cattle. One difference is, however, that cattle tend to mate all year round while the reproductive circle of the aurochs was adapted to that of the seasons, with a mating season during fall and the birth of the calves in spring. 

But that domestic cattle are a model for the aggression level of the aurochs is very unlikely. First of all, domestication likely drastically changed the hormonal system of cattle, particularly the corticosteroid hormones, what has an influence on the aggression and stress response of the animals. Furthermore, there are considerable differences between breeds in their behaviour towards humans. Highly derived breeds in particular are very agreeable, docile and have a very minor stress response. In some breeds the bulls can even be ridden. The Spanish fighting bull, on the other hand, is the complete opposite. Lidia have a very intense stress response and attack readily, although there is individual variation in “fighting spirit” within the breed. Most domestic breeds were artificially selected for agreeableness and less intense stress response, Lidia was artificially selected for an intense stress response, so that it may be the case that neither of them is a model for the behaviour of the aurochs towards humans. 

The potential for aggression, particularly towards humans, must have a genetic component otherwise it would not be heritable. The MAO-A gene seems to be different in Lidia compared to other taurine cattle breeds (go here). This gene plays a role in the endocrinology in the brain of mammals, and mutations on this gene are linked to increased aggression in other species, suggesting that this plays a role in the aggression of Spanish fighting cattle. It would be interesting to have a look at this gene in the aurochs. Since the full genome of the aurochs has been resolved, this should be possible. The MAO-A gene is probably one of many genes that influence the potential for aggression in cattle. 


To sum it up, aurochs likely would have had the potential to become very aggressive and energetic when defending itself, like other wild bovines. We do not know, however, how readily wild aurochs would have attacked if they encountered a human being that they consider threatening to them. Some aspects, like flight distance, might have partially depended on socialization. However, as Caesar writes, an individual raised under human custody likely would never lose its wild nature as they were undomesticated animals. 


All current “breeding-back” projects select against aggressive behaviour towards humans, which is understandable as they have to work with the cattle as the law dictates. As long as the animals have to be handled, it is better for the cattle and the people handling them that they do not have an extreme stress response. As we do not precisely know how aggressive aurochs were, I think it would be most sensible to let “rewilded” cattle develop their own aggression level that is formed by natural selection and thus what is best for them in order to survive in nature.


[1] van Vuure, 2005: Retracing the aurochs: history, morphology and ecology of an extinct wild ox. 




Wednesday, 28 December 2022

Reconstruction of a complete Indian aurochs skull

The Indian aurochs, Bos primigenius namadicus, is enigmatic compared to the European subspecies. Not a single complete skeleton has been found yet, and I have not seen a complete cranium either. I wanted to get an idea how the complete skull of that subspecies might have looked like, so I tracked out the namadicus skull presented in [1] (which might or might not be the same skull that is on display at the Geological Survey of India) on paper and reconstructed the complete skull using the fragmentary cranium. 


The trickiest part was to estimate how long the snout would have been. I suspect that the skull broke off right before where the nasal bone and the premaxillary bone touch each other, and that the toothless part of the upper jaw is roughly the same length in lateral view as the toothed part. The lower jaw is based on those of European skulls. This is the result:

I think the result is very plausible, it does not look proportionally weird concerning the snout length. It also looks credible for a type of aurochs that was the predecessor of indicine cattle. For comparison, here is a zebu skull. 


As no postcranial material that is worth mentioning has been published so far, I cannot do this with a complete skeleton, unfortunately. However, I think there must be enough fragmentary postcranial material of that subspecies to make a composite skeleton, so that it is possible to get an idea what the morphology of namadicus was like. A rigorous description of the postcranial skeleton of the Indian aurochs is lacking so far. 


[1] Gregoire Metairs: Evolutionary history of the large herbivores of South and Southeast Asia (Indomayalan Realm).2016. 


Wednesday, 21 December 2022

Video of fully grown Lidia bulls

Most Lidia bulls we see are young bulls at the age of three or four, because that is when they have their full body size but are comparably slender and most athletic. After that age, they become heavier, as all bulls do. It is rare that fully grown Lidia bulls are presented on the media as they are not as athletic and swift than young bulls. But here is a video of Lidia bulls that are most likely fully grown:
They are still pretty muscular, as typical for the breed, but heavier than their younger counterparts. What is most interesting to me is that a number of individuals have much more aurochs-like horns than young bulls. At the age of three, the horns are not yet fully developed and can change quite noticeably. Many young Lidia bulls have a somewhat two-dimensional horn curvature, while some of the bulls in this video have a nice primigenius spiral, in particular the bull at 5:07 and the one at 9:34. I think that supports the idea that the horns of Lidia are more often aurochs-like than what the young bulls seem to suggest, if they only get the opportunity to grow to full adulthood their horns will be more developed and that can result in a primigenius spiral. 

Thursday, 15 December 2022

A plea for more Maronesa in "breeding-back"

Maronesa is an awesome breed that I always enjoy looking at. Like all aurochs-like breeds, they have their pros and con’s. To sum them up: 


- small or at least not large body size 

- short skull shape 

- bulls can get rather short-legged and heavy 


- the coat colour is absolutely identical to that of the European aurochs 

- the sexual dichromatism is nearly always present and well-marked, identical to that of the European aurochs 

- the horns can face inwards in a very aurochs-like manner 


Although the number of pros and con’s that come to my mind is the same, I think the benefits of that breed outweigh the undesired traits. That is, for once, because it is very, very rare that a cattle breed has a colour that is truly identical to that of the European aurochs – actually the only other European breed that I know of is the old lineage of Corsican cattle, which is critically endangered if not has already disappeared. It’s impressing to imagine that during roughly 10.000 years of domestication, not a single domestic colour mutation has found its way into the Maronesa genome. But even more important is the fact that the sexual dichromatism is nearly always present and as well-marked as in the European aurochs, because sexual dichromatism is a complex trait that is very difficult to breed for in domestic cattle. I did a post on that, coming to the conclusion that the only way to achieve an authentic dichromatism in “breeding-back” is to rely on a breed that already has it to the desired extent. That would be Maronesa. At least I know of no other breed that has an authentic dichromatism except for the old lineage of Corsican cattle. Also, the horn curvature of some Maronesa is very useful as the horns curve very strongly inwards in an aurochs-like manner. This is very rare even among aurochs-like cattle. Just look at this cow. Overall it has great potential for aurochs-like offspring. The colour is perfectly identical to that of the aurochs, the horns curve inwards in an aurochs-like manner and it has a perfect dichromatism (I assume so because it is the rule in the breed and there are no lightly coloured Maronesa bulls). 


Considering the potential of the breed, I think it is dramatically underused in “breeding-back”. The only current project that is using Maronesa is the TaurOs Programme. That is problematic because they use only a small number of Maronesa individuals, they do not execute selective breeding but let the cattle breed for themselves instead, they crossbred them with breeds that are not really beneficial from the perspective of aurochs-likeness (f.e. Maremmana) and the results are modest. And that is although the project would badly need good Maronesa to improve the horn shape of their cattle, as the horns of most TaurOs cattle face outwards, and the sexual dichromatism which is completely absent in some herds (f.e. Milovice). I would highly recommend the Tauros Programme to try to achieve another herd of Maronesa from Portugal, this time better individuals (that have truly inwards-curving horns and a good morphology etc.), also including grown bulls, as bulls have a greater influence on the herds than single cows. 

Also, Maronesa could be beneficial for the Auerrind project in the future. That would depend on how good the dichromatism is going to get with the set of breeds currently used – Maremmana, Sayaguesa, Watussi and Grey cattle have a rather reduced dichromatism, Pajuna can be good in this respect, and in Chianina a dichromatism is possible but masked beneath their colour dilution if present. If it turns out in the future that Auerrind crosses do not have a well-marked dichromatism and inwards-facing horns, including good Maronesa could be beneficial. But as for now it is too early to judge that, as the second-generation crossbreeds are not fully grown yet. 

Maronesa would even be an option for Heck cattle breeders to increase the aurochs-likeness of their cattle. Some Heck cattle breeders don’t like large individuals, or simply like the looks of Heck cattle regardless of their aurochs-likeness. Maronesa would improve the horn shape and sexual dichromatism without altering the looks and body size of Heck cattle dramatically. But Heck cattle would not be my first choice to crossbreed good Maronesa with, to be honest. 

Would TaurUs cattle benefit from Maronesa? I am not sure about that. Many Taurus cattle in the Lippeaue already have inwards-facing horns, and the sexual dichromatism is good in the herds as well – I examined it for the year 2015 using a photo archive, and it turned out that more than 80% of the individuals have the “right” colour. Go here for the post. Apart from that, they have done a good job at creating truly large cattle, Maronesa might diminish that. As most of the achievable aurochs-like traits are already present in the Lippeaue, I do not think that Maronesa would be necessary or, considering their con’s, worth the effort in Taurus cattle. 


Another option to seize the potential of Maronesa would be conducting a new, heavily Maronesa-based breeding project. I would use Maronesa, Chianina and Watussi for such a project. Precisely, I would create a number of F2 Maronesa x Chianina, and F2 (Maronesa x Watussi) x Maronesa, and then create an F2 from the combination of both lineages. That would take five breeding generations, and thus roughly ten to 15 years, but the results could be quite qualitative. 


I think it would be a shame if Maronesa was not used on a larger scale in “breeding-back”. That is also because it seems that the aurochs-like less-derived Maronesa lineages are endangered. From what I have heard, the sexual dichromatism is not always appreciated by Maronesa breeders and there are already some almost black Maronesa cows. If that trend continues the breed might lose its dichromatism and end up looking like Sayaguesa in that respect. Also, some Maronesa are bred for an extremely massive body with a bulldog face, and many Maronesa cows have corkscrew-like horns (I do not know what is the preference of Maronesa breeders regarding horn shape). The less-derived type of all aurochs-like landraces is endangered because of crossbreeding with more economically productive breeds and/or selection towards a more derived appearance, and so is that of Maronesa, at least because of the latter factor. Thus I really hope that “breeding-back” will seize the potential of that breed, and that the less-derived aurochs-like representatives of Maronesa do not disappear without contributing noticeably to the “breeding-back” gene pool.