Hi there! I'm Rebecca, one of the new research assistants here at TEI. I'm from central Massachusetts, so this has certainly been a big change in climate/geography/language from home. After a month in the Golden Triangle, I think I'm finally settling into life in a Thai village (of course, I don't think I'll ever get used to elephants!). One of the things I find most interesting about elephants is the relationship between them and humans, and the ways that we have affected each other.
Elephants have worked with humans for thousands of years--in Thailand, elephants are inexorably tied to every aspect of the culture. Elephants were used in war, as a symbol of royalty, in the logging industry, and, more recently, in tourism. However, are these animals what we would consider "domesticated?" In order to answer that question, we need to look at the history and the science of the domestication process.
Domestication, in the most technical sense, is the process of artificial selection. This means that humans, versus evolutionary pressures, artificially choose what traits should be passed on in an animal population. In dogs, for example, humans looked for friendliness, loyalty, and, in some breeds, a specific hunting ability. Corgis were bred to herd livestock, and thus even corgis that have never worked on a farm will instinctually try to "herd" other animals (or even children!). Dogs have thus evolved alongside humans, and have developed significant abilities in understanding human behavior. Most interestingly, dogs can recognize the meaning of a human pointing to an object--they can even follow a person's gaze to locate a hidden object. Wolves, on the other hand, do not understand these types of gestures. Even wolves raised in captivity do not have this ability.
Cardigan Welsh Corgi and Canis lupus photos via Wikimedia Commons
In addition, domesticated dogs are physically different from their wild predecessors. Many of these differences were chosen artificially for aesthetic reasons, but some changes in physical appearance may simply be part of the domestication process. During the 1960s a study was started in the (then) Soviet Union on the domestication of wild foxes (Trut, 1999). Researchers selected fox pups based solely on temperament; the most friendly pups were chosen to breed and have pups of their own. In only a few generations, the scientists were reliably producing foxes that were friendly and playful with humans. However, they also discovered that the foxes were physically different from their wild cousins: the adult domesticated foxes had floppy ears, curled tails, and some developed piebald coats. None of these traits are expressed in adult wild foxes; they are, however, found in pups. Domestication causes neotony, a process through which adults retain juvenile physical traits. This is why dogs look more like wolf puppies, rather than adults.
Finally, domestication also changes animal brains. The brains of domesticated animals are smaller than their wild counterparts, possibly because it results in a reduction of aggression (McAuliffe, 2011). In addition, gene expression levels in the brain differ between domesticated and wild species (Albert et al., 2012). It seems logical that dramatic behavioral changes would accompany cerebral changes.
But what about elephants? Although elephants raised in captivity can be friendly and even affectionate with the humans they work with, they are not domesticated. They have not changed in appearance due to generations of human contact, and are behaviorally no different at birth when born to captive versus wild mothers. If a calf were born to a captive mother but raised in the wild, that calf would become a wild adult. On the other hand, a dog raised in the wild will still retain domesticated characteristics. This is exciting for our research--we are able to test the intelligence of a group of wild animals in a controlled and relatively safe setting. And most importantly, we can use our research and elephants here in the Golden Triangle to help wild elephants throughout the rest of Asia.
Albert FW, Somel M, Carneiro M, Aximu-Petri A, Halbwax M, et al. (2012) A Comparison of Brain Gene Expression Levels in Domesticated and Wild Animals. PLoS Genet 8(9): e1002962.
Canis lupus lupus By Quartl (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons
Cardigan Welsh Corgi By Kubek15 (own work on my camera) [Public domain], via Wikimedia Commons
McAuliffe, Kathleen. "If Modern Humans Are So Smart, Why Are Our Brains Shrinking?" Discover. January 20, 2011.
Trut, Lyudmila (1999). "Early Canid Domestication: The Farm-Fox Experiment". American Scientist 87 (2): 160.