I was asked by Skyman today to comment on this article. It is basically a long argument for why vegans should eat oysters, a subject on which I have no strong views, except that doing so would rob you of the purity of the title “vegan” but allow you to eat a slimy sea-creature that tastes mainly of salt and mud. I had my fill of oyster and clam in Japan, and despite going to an oyster festival where there were dozens of different dishes based on oyster, not a single one of them were very tasty. Eating oysters is very much like collecting the snot of a crew of fishermen as they come back from sea, boil that, and then call it delicacy.
One of the author’s footnotes, however, is very interesting. He writes:
The main argument of Animal Liberation is that discriminating against nonhuman animals is indefensible because it makes irrelevant category distinctions—pain cuts across species barriers. But to loop oysters into a dietary taboo simply because we’ve labeled them animals is to make just such a faulty distinction. Likewise, we shouldn’t be eating more plants because they are in the plant kingdom; we should eat them because it’s a sound way to feed ourselves without causing a lot of damage to the world. And oysters, as far as we can tell, belong with plants in almost every ethically relevant way [Footnote].
[Footnote:] These kingdom distinctions were demarcated by Carolus Linnaeus, who also believed that Africans and Europeans were different species. I don’t let Linnaeus tell me what to eat any more than I let him tell me who is human.
I haven’t had an internet connection regularly when I’ve been in Sweden, so this is perhaps the most inane thing I have read in the last month of so that hasn’t emanated from the government. Here are some objections:
1. Linnaeus didn’t demarcate these categories
The categories “Plants” and “Animals” were not actually demarcated by Linnaeus, they existed long before Linnaeus, at least as far back as Aristotle. Thus, even if you disagree with Linnaeus’ classification of humans, there is no reason for this to colour your disagreement on the division between animals and plants.
2. Linnaeus is, of course, not dictating anything
An obvious point. Linnaeus’ classification is irrelevant to your dietary choices. “Vegan” is defined by the built-in dictionary of my Mac as “a person who does not eat or use animal products”. Linnaeus is telling us what an animal is (1); some one else defined “vegan” based on this. The issue, here, is thus obviously with the word “vegan”, not with the Linnaean concept of animals. The division between animals and plants (and other kingdoms) is not an arbitrary lunch recommendation for the convenience of the vegan middle class, but statements of monophyly and distributions of characters in the biological world over evolutionary time.
3. There is no connection between one part of a classification and another
The classification of one part of the tree of life is essentially independent of the classification of another part, in that even if the classification of the first part is unacceptable for some reason, that does not invalidate the classification of another part at all, unless it can be shown that this part is also unacceptable. A single perceived or actual flaw does not invalidate the whole. Which leads to perhaps the most contentious objection:
4. There is nothing actually wrong with Linnaeus’ division of humans
Two things must be understood:
– Taxonomy and classification is founded on convenience, and not an objective representation of existing structures or sets in nature;
– The lumping of all extant human populations in the same species, not divided into subspecies, is a political decision, not a biologically privileged one.
The first point is easy to understand: we cannot simply look up the answer at the back of the book, and there is thus no correct classification of all organisms. Moreover, over evolutionary time, this classification would necessarily change, meaning that any classification is a snapshot, not the final answer. The basic reason for erecting a classification (2) is therefore convenience, which is one of the reasons that the classifications of different parts of the tree of life are based on different considerations. Some groups of organism have characters that make them easy to split, and may thus be convenient to have a classification with lots of similar species. In other groups, it is more convenient to treat the organisms as larger units. Neither method — nor any form of middle road! — is more generally correct than the other, as organisms are not homogeneous.
This means that when two specialists disagree on whether to treat a group of organisms as different species, subspecies, genera, or even all the same species, neither of them is correct in any general sense of the term. It all depends on the organisms as well as on what is most convenient (as well as some scientific political, of course…). Is it convenient to divide Anatoecus on different host species into different species or subspecies, as was done by Zlotorzycka (1970), or is it more convenient to treat them all as the same, very widely distributed, species, as was done in the recent checklist of Price et al. (2003)? Without knowing the group, it is impossible to know (3).
The same goes for humans. There is nothing special about human variation that sets it apart from variation within any other species (or between any other pair or group of species). Whether or not we treat all humans as members of the same species or not in a matter of convenience, and as conservatives have traditionally emphasized the differences between people by using concepts close to their hearts such as racism and slavery, it has become most convenient for us to treat all humans as the same subspecies.
However, imagine an Earth on which everything is identical, except that humans did not develop long-distance communications or transportation; in essence, human populations colonized the entire world, became sedentary and stayed sedentary for an indefinite time, allowing them to acquire their various characteristics such as skin colour, size differences, body shapes, and so on. If an impartial observer (perhaps some of the Martians usually employed for such purposes) were to do a complete classification of life on Earth, would these observers, freed from the political considerations of modern human society, lump all humans together in one species or subspecies, or in several? Even if we assume that they have developed taxonomy and classification the same way as we have, it would be impossible to know. It would likely depend entirely on what is convenient for them, just as Linnaeus’ classification depended on what was convenient to him.
Some further clarifications to respond to some ill-thought-out points that are usually raised at this point:
– Linnaeus did not himself travel very much outside Sweden, and non-European people were not yet very common in Europe. This implies that Linnaeus likely based his division of humans (as with so many other species) mainly on hearsay and second-hand facts. It seems reasonable to assume that, at the time when Linnaeus wrote his books, he actually could not tell whether or not the people he heard about in China, Africa, and America were the same species as the ones he was more familiar with in Europe. At the time, for instance, Europeans had barely discovered Australia, and its fauna (yes, humans are included in “fauna”) was largely unknown and very unfamiliar. It is certainly plausible that based on the data Linnaeus had available, a division of humans into several species was simply the most convenient way, as it was not known whether the various colonized people were the same species or not.
– There is no convenient general morphological character that can be used to differentiate all species. Birds are usually separated on characters such as plumage, bone structure, and song. Bird lice are usually separated on male genitalia, chaetotaxy, and the structure of the head plates. Neither of these sets of characters can be transposed to the other group and make any sort of sense. This is true even at lower taxonomic levels. For instance, Lunaceps species are often told apart on preantennal structure and chaetotaxy, whereas Meropoecus species are more easily separated on male genitalia. Note that this is probably a relatively modern viewpoint, and that older taxonomists often used whatever they could see to separate species. In that context, two species that are more or less identical but differ in colour — as are Carrion Corvus corone and Hooded Crow Corvus cornix — can be conveniently listed as separate species, simply because it is possible to tell them apart on an obvious character. This is not automatically wrong in other species, and it is not wrong in humans either.
– The fact that there is more genetic variation between humans in sub-Saharan Africa than in the rest of the world combined (or some such fact which is often alluded to) is immaterial. This does not in any way disprove Linnaeus’ division of humans into a certain number of subspecies, or even species. Such data could as well be interpreted as requiring the erection of more different subspecies in Africa, which is a solution not incompatible with Linnaeus’ classification (nor with linguistic and morphological data) (4). That a given classification is imperfect does not imply that all classifications based on the same principles are, it may just be imperfect due to poor data.
– There is nothing in the concept of subspecies that implies that one group of organisms is in some way inferior to another. The nominate subspecies is simply the first one to be described formally (= the nominate). Just as standard languages are just one dialect among many, so the nominate subspecies is just one subspecies among many, and takes precedence only for nomenclatorial purposes. The fact that conservatives have arranged society according to their delusions, with themselves on top, does not in any way influence the scientific principles of taxonomy.
There is thus nothing wrong, scientifically, in considering different populations of humans in Linnaeus’ time different subspecies, and if such a division was the most convenient, it would even be desirable. These days, when people travel much more and have the opportunity to mate with people from other populations, these divisions are of course harder to defend. However, as a general principle, the majority of people likely still mate mainly with people that would be classified as the same subspecies, and hybridization does not normally cause any problems in subspecies delimitation in other animals (5). Only because of politics do we not retain these divisions.
(1) However, in bis original classification some algae were classified as animals, which is not where they are placed today.
(2) And one that is generally overlooked by people who support the “PhyloCode” and other methods for maximizing the number of times you see your name in print after a taxon name.
(3) In this case, I happen to agree with Price et al. (2003), at lest for now, as there appear to be no way to tell the various species of Anatoecus apart morphologically. It may be possible genetically, or by using more modern techniques, but for now, the most convenient way to divide Anatoecus is to treat it as a few widely distributed species. What is most convenient may of course change when more data has been taken into consideration.
(4) Note that a common line of evidence in delimiting bird species is playback trials (the so-called “recognition species concept”). In this method, birds of population A are recorded, and these recordings are then played back to population B. This is typically done with territorial singing during the mating season. If population B reacts violently, he obviously considers population A a rival, and this can be interpreted as the two populations belonging to the same species. If there is no reaction, population B does not seem to consider A conspecific — just as they don’t consider species F, which is clearly not the same species, conspecific — and this could imply that the two populations are different species. Imagine if the same thing was done to humans! People from Denmark, whose gruntings are unintelligible to all other humans, would be their own species!
(5) Though they may of course cause problems in subspecies identification.
Price, R.D., Hellenthal, R.A., Palma, R.L., Johnson, K.P., Clayton, D.H. (2003). The Chewing lice: world checklist and biological overview. Illinois Natural History Survey Special Publication 24. x+501 pp.
Zlotorzycka, J. (1970). Studien an den mitteleuropäischen Arten der Gattung Anatoecus Cumm. (Esthiopteridae, Mallophaga). Polskie Pismo Entomologiczne, 40, 7-67, 12 photos.