Striving for Clarity and Accuracy

There are various aspects of academia that some of us take for granted, without critical thinking. The driving "wisdom" here, is that if an idea is an oft repeated or recited one in sections of academia, then it must certainly be accurate and doesn't call for further investigation. This almost certainly appears to have been the case in a recent personal encounter with a question dealing with "bovine" taxonomy, one concerning the Fulani cattle in particular. It has generally been the case in "western" academic circles, to casually refer to Fulani cattle breeds as "West African Zebu", and as such, one opinion encountered fairly recently in an internet discussion forum, figured that such a description is fine and dandy, because Zebu happens to be accompanied by the "West African" descriptive, thereby invoking the subspecies' precise African origin. That may well be so, but does that at any rate, necessarily render the Zebu-characterization correct? After all, here, it is not simply the matter of the cattle subspecies' geographical origin, but its actual genealogical heritage. As far as the latter goes, i.e. the genealogical question, this was greeted with an explaining-away that "implicitly" argues that the West African "Zebu" makes sense given the relatively predominant Zebu genetic contribution over those of other bovine lineages [namely the Bos Taurus — either African and/or European] in the West African "Zebu" gene pool. To this end, sources such as that compiled by E. M. Ibeagha-Awemu. et al. 2004 have been offered as evidence; it goes like this:

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The argument given based off this piece of information, as it goes, appears to be that most of the Bovine types sampled herein are "hybrid", because of their apparent "inter-subspecies" ancestries, and that notwithstanding, has no bearing on their assigned taxonomic identity; the unspoken "wisdom" here, is that since this piece of information appears to suggest that most cattle breeds out there are rarely "pure", and hence are inclined to be "hybrid", then the condition of having ancestry from divergent subspecies doesn't have any bearing on a cattle breed being assigned to only one of the subspecies. Instead, contribution from the other parental subspecies — whose taxonomic identity had not been assigned to the offspring — is interpreted here as "admixture". The tacit premise—wittingly or unwittingly—that this logic lies on, is that the breeds are assigned their taxonomic identity based on which parental type's contribution to their gene pool supposedly 'predominates' or 'prevails' over others'. Indeed, just reading off of that table above, for example, one comes out with the understanding that many of the African breeds assigned the "Zebu" descriptive appear to have more "Zebu" contribution than their Bos Taurus counterparts. However, further investigation involving other set of markers cautions that the situation is more complex than that imagery.

You see, one has to bear in mind, that we are dealing with domesticated fauna here, which means that whether or not the herders are actively aware of the precise set of phenomena that impart advantageous features to their livestock, awareness of a trend(s) in the success of a breed will lead to every effort [by the herders] at sustaining or maintaining, if not swelling the populations of said breed. The type of markers implicated in the table above, do not necessarily allow one to adjudge the significance or precise magnitude of contribution from the parental inter-subspecies elements involved; and why is that? Because again, the Fulani was the product of domestication, meaning that it was intentionally crossbred to bring out and retain certain advantageous features from the contributing parental bovine subspecies types. These advantageous features would have had to have been encoded in certain DNA nucleotides, rendering certain DNA loci under "selection pressure". Such a situation would therefore make these loci insufficient in ascertaining the actual level of respective contribution from the contributing parental bovine "inter-subspecies" involved. Other loci may well simply be relatively stable in the face of random genetic drift, by chance occurrence. For instance, a largely "hybrid" population comprising Zebu-Taurine individuals might not accurately reflect contribution of the "parental" subspecies involved, because certain loci could, by chance occurrence meted out by "positive" random genetic drift, remain relatively stable in their distribution across the population, simply because the number of "hybrid" individuals which just-so-happen to be homozygous at the locus in question happens to be the relatively overrepresented one than that comprising individuals which are heterozygous at said locus. To demonstrate how all this could be, one only need to look at what uniparental genotyping from the so-called African Zebus thus far reveal: these tests show that in the case of West African "Zebu" breeds, a majority of them have "Zebu" paternal ancestry, but by contrast and almost "exclusively", they have the Bos Taurus maternal ancestry! This is a true definition of a "hybrid" ancestry. It is not as if the West African "Zebu" are largely "Zebu" in both maternal and paternal ancestry, and that only a small segment of their population is "Zebu" and "Bos Taurus" in ancestry, so as to deem the "aberration" as "admixture", but that this is true for virtually all the African "Zebu", that they happen to have both "Zebu (Bos Indicus)" and "Bos Taurus" uniparental ancestry.

Yes, there are hybrids amongst the so-called African breeds of "Bos Taurus" as well, but unlike their so-called "Zebu" counterparts, uniparental genetyping show that there are actually sizable populations of these "Bos Taurus" who have virtually ONLY "Bos Taurus" ancestry both maternally and paternally.

The argument that many herds are likely to have "inter-subspecies" ancestry, and therefore are 'hybrid' and the condition has no bearing on their assigning to one or the other taxonomic [bovine] group, is immaterial to the fact that genealogical and archeological particulars point an "independent" African Bos Taurus domestication, and hence, considered a "true" phylogenetic entity on its own that distinguishes it from the "Near Eastern" or European Bos Taurus and Bos Indicus. Nor is it necessarily the case, as uniparental genotyping attest to, that African Bos Taurus populations are inclined to be breeds of "Taurine-Bos Indicus" lineage; there are considerable populations of African Bos Taurus, particularly in Western Africa, that are still virtually all Bos Taurus in their lineage! This however, as just demonstrated, is not the case with the western African "Zebu" breeds like the Fulani. The following piece, from Blench et al.'s compilation, gives us an illustration of what has just been described, in relation to uniparental genotyping:

And...

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The other argument made, in addition to the genealogical one just examined, goes like this:

They are zebu, African zebu, as their physical characteristics and their genetics make clear.

Indeed, the present author of this blog is aware of the naming schemes based primarily on morphological traits; that though, says little in actual genetic basis for such terminology. In fact, many of the so-called West African "Zebu" breeds appear to bear traits that are considered "intermediate" in relation to Asian Zebu breeds. This includes things like for example, the less prominent humps on many of the West African "Zebu" breeds when compared to those of their Asian counterparts. It has even led to coining of such terms like "Zeboid"; see, courtesy of Blench et al.'s compilation:

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Generally, the bovine subspecies have become casually synonymous in dichotomous terms, with hump-less breeds being synonymous with "Bos Taurus" or Taurine descriptive and humped subspecies being synonymous with the "Zebu" descriptive; this, usually regardless of actual genealogical particulars.

The last line of defense for upholding the viewpoints examined and rebuked [or at least challenged] herein, about the justified assigning of West African "Taurine-Bos Indicus" hybrid breeds like the Fulani to just the Bos Indicus taxonomic group, appears to one of logical fallacy 'appeals to popularity'; that is to say, that many in "western" academia circles simply refer to Western African breeds like Fulani as West African "Zebu", and therefore they must necessarily know all and have the last word on the subject matter. Any challenge to this viewpoint or call for further investigation into the subject matter, to iron out potential incoherencies, peculiarities or inadequacies is dismissed out of hand as emotionalism or an attempt at making an argument simply for argument's sake. It matters not, the fact that all the sources cited by its defender (advocate) too agree with the position maintained by the present author of this blog, as well as "materially"-supported [as the plentiful citations herein bespeak] by the present author, that the so-called West African "Zebu" are IN FACT "hybrid" breeds of BOTH "Bos Taurus" and "Bos Indicus", and so from that fact alone, it would actually be inadequate and inaccurate to deem these hybrid breeds as simply "Zebu". Superficial reasonings aside, the taxonomic assignment as such doesn't really reflect the genetic reality at hand, other than its ardent defenders crying that the Zebu do in fact form part of the genealogy; but still the keyword here, is "part"! A defender of the said taxonomic assignment even went as far as using human socio-constructs as the presumably perfect analogy of the situation at hand, pointing out that despite "hybrid" ancestry, humans are inclined to assign themselves to just one "ethnic"/"racial" group or the other. If said defender were not blindsided by ideology, it would have occurred to the person that not only are the socio-contructs in question not regarded as scientific, but also humanity from a biological standpoint, does not comprise of several distinct "sub-species"; our variations have not been that significant to warrant division of humanity to several distinct subspecies. Such is the sort of weight [as it relates to substance] with which the layperson approaches questions relating to the subject matter of this very blog topic. Is it possible that better explanation is afforded by the more informed defenders, lettered in the disciplines of bioanthropology and molecular genetics, than those examined herein? Perhaps, but from accessible material spread over the net and libraries, none has come to attention that adequately and accurately justifies the taxonomic assignment of the West African Bos Indicus-Taurine 'hybrids' to just the "Zebu" phylogen. The quest for accuracy and clarity should not be dismissed as an abomination, but as an opportunity for furthering knowledge, and the specifics demonstrated here thus far go to show just why!

*As always: Lookout for ongoing updates; notes on this site are regularly updated as information comes to attention!