Domestication can have a very simple definition: one of those definitions so simple, it’s hard to put into words; it just is. Cats are domesticated, dogs are. Domesticated creatures are cute, friendly – not always, maybe, in the case of cats – and they live with us, in or around our homes.
However, considering this very interesting evolutionary development from a biological stance, domestication becomes harder to define. This difficulty, and exploring why it is difficult to define, broadens the debate around domesticated species. It asks us to question what species are domesticated, which species are doing the domestication, what is needed for domestication to occur, and whether we aren’t, ourselves, actually domesticated.
What is domestication?
It has one answer to the everyday individual, another to the evolutionary biologist, and many more variations besides after you’ve asked either’s peers. But it is a question that does have an answer, for all of us.
So, before we get into considering whether the elephant or the human being is domesticated, using a tempered version of our own answer is a great place to start in beating out a definition.
Cats and dogs are the quickest species called to mind when we consider domestication. They’re domesticated because they live with us, are fed by us, and because they do things for us. They’re also domesticated because they’re cute and they like and/or accept our affection.
Cattle, pigs and horses are also domesticated. Our relationship with them isn’t quite so tactile but we do also control their fitness, garner resources and/or services from them and they gain something, in terms of their evolutionary fitness, from the association.
Grasses and certain crops have also been domesticated. There’s none of the stroking and the petting, there’s not even any grooming. However, you’ll see that they’re relationship with us can be described in similar terms to that applied to our relationship with cattle, pigs and horses.
These relationships all fit neatly within an attempt at defining domestication by a scientist at the Centre for Genomics and Systems Biology of New York University, Dr. Michael D. Purugganan. Purggannan attempts to tie several thousand words worth of consideration on the question that he did for Science Direct into a collection of ‘critical elements’ that shape it.
Purugganan states that domestication is “(i) an evolutionary process, (ii) arising from mutualistic ecological interaction, (iii) involves constructing an environment where there is control of the fitness of one species by another, (iv) occurs so that the domesticator can garner resources and/or services from the domesticate, (v) leads to fitness benefits that accrue to both partners, and (vi) is agnostic to the interacting species.”
What Purugganan doesn’t do, in his definition, is make any reference to the physical attributes of domesticated species. They definitely change as a living organism becomes domesticated; all of the above examples are testament to that. Perhaps, however, he doesn’t put this fact into his definition because changes to physical attributes is an expression, not a definition part, of domestication.
What Purugganan does do is take his definition out of the anthropocentric. His definition of domestication describes ‘domesticator’ and ‘domesticate’; it notes that this isn’t just a process done by human beings to other species.
In his lengthier discussion on the topic, he gives examples. Ambrosia beetles farm fungi, as do some 330 different species of termite. Damselfish farm a red algae species even to the degree of protecting it from other species and weeding out other algae ‘weeds’.
These last two points are important.
It is important to consider, though we might often forget it, that we aren’t the centre of the universe. We aren’t even the centre of our planet. We are a living, adapting, interacting part of this vast global ecosystem and, as proven by the fact that we have both canine teeth and an appendix (regardless of the fact that it is now defunct) this planet has and will continue to push and pull us around on our evolutionary path.
This message is central to the importance of the fact that domestication changes a species’ physical attributes. Physical change is the evidence of domestication; it is the advertisement pointing to an evolutionary legacy. The cuteness of cats and dogs illustrates a path taken.
Have human beings been domesticated?
Charles Darwin considered the question of whether humans were a domesticated species in his book Descent of Man. The question arose out of comparisons between human beings and other clearly domesticated animals. In both species, observable over time, is a gradual change in appearance and character: a softening of features, a shrink in size, reduction in tooth size, greater docility, less propensity for reactive aggression.
Darwin, and indeed Purugganan, both reject that human beings have been domesticated. Darwin did so with an argument predicated on the fact that human beings had not had their fitness controlled by another species. It has and can be argued otherwise.
The shortening of the hominid’s brow, the shrink in its brain size and face was accelerated around 10,000 years ago, just after the agricultural revolution. That development can be considered an element of evolutionary fitness being impacted by the influence of another species (domesticate and domesticator roles here considered in the reverse).
The argument has either way has no conclusive answer. It becomes even messier when one considers the notion of self-domestication. Darwin and Purugganan area again in concert here: they both consider self-domestication an untenable notion. They note the similarities shared in the changed appearance of domesticated species and humans and bonobos (bonobos being the only other species some consider to be self-domesticated) but they discount that this was done by the process of domestication.
They do so because of the fact that, in their definition, domestication has to be an example of mutualism, that two species, one exerting greater control, has to be a part.
However, that doesn’t discount that a process, similar in result – in both appearance and character – to domestication, occurred in humans and bonobos.
(Before we continue, it’s worth giving some information on why the bonobo is often considered in the conversation of ‘self-domestication’. The bonobo is a close cousin of the chimpanzee but it, in its distinction from its cousin, shares some of the hall-marks of domestication: it is less aggressive, has softer features, and, apparently also important, has a love of and social application for sex, using it to make friends and build relationships.)
So, are elephant being domesticated or, even, domesticating themselves?
No other animal species – save humans or bonobos – can be considered within the already problematic conversation of ‘self-domestication’. No other animals save, perhaps, elephant.
Perhaps, as Melinda Zeder, emeritus archaeologist at the Smithsonian Institution, states ‘self-domestication’ is a “meaningless term that muddies the waters”. Perhaps you do need a domesticator and a domesticate for the process to happen. But that doesn’t change the fact that some of the expressible qualities of domestication occur, and are seemingly occurring more often, in elephant with greater frequency than in any other animal species.
An evaluation of research condensed for the online science journal, Science.org, found that researchers have documented 19 cognitive, behavioural and physiological traits common to humans and bonobos and found in no other species save elephants.
Another team, analysing the genome of African elephants found that 674 genes were in the process of rapid evolution. They compared these genes with some 764 that have been identified as linked with mammal domestication and found that several of the 674 found in elephant shared a close association.
The researchers do, astutely, counsel caution in interpreting this data. It is too early to determine what result the rapid evolution of these genes will have on an elephant’s outward expression. However, evolution is constant, changes are coming. There are signs suggesting that elephant will look and behave more and a little more like domesticated creatures, a little more like us.