The modern domesticated horse (Equus caballus) is today spread
throughout the world and among the most diverse creatures on the
planet. In North America, the horse was part of the megafaunal
extinctions at the end of the Pleistocene, but not, for some reason, in
Europe. Two wild subspecies survived until recently, the Tarpan (Equus
ferus ferus, died out ca 1919) and Przewalski's Horse (Equus ferus
przewalskii, of which there are a few left).
Horse history, especially the timing of the domestication of the horse, is
still being debated, partly because the evidence for domestication itself
is debatable. But interestingly, genetics seems to suggest a single event
of domestication. Unlike other animals, criteria such as changes in body
morphology (horses are extremely diverse) or the location of a particular
horse outside of its "normal range" (horses are very widespread) are not
useful in helping resolve the question.
Horse History and the Evidence for Horse Domestication
The earliest possible hints for domestication would be the presence of
what appear to be a set of postmolds with lots of animal dung within the
area defined by the posts, representing a horse pen. That evidence has
been found at Krasni Yar in Kazakhstan, beginning about 5000 BC. The
horses may have been kept for food and milk, rather than riding or loadbearing.
Accepted archaeological evidence of horseback riding includes bit
wear on horse teeth-that has been found in the steppes east of the Ural
mountains at Botai and Kozhai 1 in modern Kazakhstan, around 35003000 BC. The bit wear was only found on a few of the teeth in the
archaeological assemblages, which might suggest that a few horses
were ridden to hunt and collect wild horses for food and milk
consumption. Finally, the earliest direct evidence of the use of horses as
beasts of burden-in the form of drawings of horse-drawn chariots-is at
about 2000 BC, in Mesopotamia.
• Horse Corrals at Krasni Yar?
Horse History and Genetics
Genetic data, interestingly enough, has traced all extant domesticated
horses to one founder stallion, or to closely related male horses with the
same Y haplotype. At the same time, there is a high matrilineal diversity
in both extant and wild horses. At least 77 wild mares would be required
to explain the diversity of the mtDNA in current horse populations, which
probably means quite a few more.
Three Strands of Evidence for Domesticated Horses
In a paper published in Science in 2009, Alan K. Outram and colleagues
looked at three strands of evidence supporting horse domestication at
Botai culture sites: shin bones, milk consumption, and bitwear. These data
support domestication of the horse between about 3000-3500 BC sites in
what is today Kazakhstan.
Horses skeletons at Botai Culture sites have gracile metacarpals. The
horses' metacarpals-the shins or cannon bones-are used as key
indicators of domesticity. For whatever reason (and I won't speculate
here), shins on domestic horses are thinner--more gracile--than those of
wild horses. Outram et al. describe the shinbones from Botai as being
closer in size and shape to those of Bronze age (fully domesticated)
horses compared to wild horses.
Fatty lipids of horse milk were found inside of pots. Although today it
seems a bit weird to westerners, horses were kept for both their meat and
milk in the past--and still are in the Kazakh region as you can see from the
photograph above. Evidence of horse milk was found at Botai in the
form of fatty lipid residues on the insides of ceramic vessels; further,
evidence for consumption of horse meat has been identified at Botai
culture horse and rider burials.
Bit wear is in evidence on horse teeth. Researchers noted bitting wear on
horses' teeth--a vertical strip of wear on the outside of horses' premolars,
where the metal bit damages the enamel when it sits between the
cheek and tooth. Recent studies (Bendrey) using scanning electron
microscopy with energy dispersive X-ray microanalysis found
microscopic-sized fragments of iron embedded on Iron Age horse teeth,
resulting from metal bit use.
Author: Kris Hirst
From: www.About.com