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presence of leopard spotting amongst Botai horses implies a degree 
of human selection and husbandry. The selection may have been 
intentional to increase the number with a desirable coat colour, but 
husbandry might equally have removed causes for negative selection 
normally seen in the wild.
Secondly, horse demographic profiles, in terms of changing 
effective populations, can be modelled over time from levels of 
genetic drift. Such a Bayesian demographic profile for horses shows 
a strongly negative trajectory from the last glacial maximum into the 
early Holocene, something that only reverses again after the spread 
of domestic horses in the last 5,000 years. The horse went extinct in 
North America, whilst in Eurasia it appears populations were also in 
severe decline and becoming more fragmented. Having been mixed 
hunter-gatherers through the Mesolithic and Neolithic, it seems 
almost inconceivable that, faced with plummeting horse populations, 
they would suddenly focus all their effort on hunting just that species 
whilst simultaneously becoming less mobile and settling in large 
villages. On the other hand, if their reaction to the problem was to 
domesticate the animal, breed it and control it, then this sudden 
change of lifestyle makes sense. However, having added yet more 
strong lines of evidence that Botai horses were domestic, this new 
work also shows that Botai horses were not the main genetic source 
for modern domestic horse stock. One obvious implication would be 
that there is a second, and more successful, centre for early horse 
domestication, and that second clade comes to dominate with only a 
limited amount of Botai admixture surviving by the Iron Age.
In addition to having whole genomes for Botai horses we now 
also have three whole genomes for Botai humans, and indeed a series 
of other Eneolithic and Early Bronze Age peoples of the northern 
Central Asian steppe. These results are also surprising and 
significant. They show that the people of this region at this time were 
effectively a very late relict population that had changed very little 
over the thousands of years since the Palaeolithic and showed little 
sign of admixture from outside. There are a series of significant 
implications to this, but in relation to
Botai it tells us something about the possible circumstances of 
horse domestication in that culture. Zeder (2012) laid out a number 

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of pathways to animal domestication: ‘commensal’, ‘prey’ and 
‘direct’. Commensal is where an unintended close living association 
might eventual change into domesticity, with the dog being an oft 
cited example of this. Prey route is where the relationship with a 
common quarry changes over time (again potentially unintentionally) 
to involve more and more control. This is the most common form of 
domestication relating to food animals and one most frequently 
undertaken by peoples who were already plant agriculturalists, but 
still hunted animals. Directed pathway domestication implies a prior 
knowledge of what it is to domesticate an animal and the deliberate 
act of targeting a species to do that. Zeder cites horse as an example 
of the rare direct pathway and thus suggests that, as a relatively late 
example of a major domesticate, it was targeted by people with 
knowledge of the process themselves or through interaction with 
others, as suggested by Anthony and Brown (2011). However, in the 
specific case of the Botai, the genetics implies continuity of local 
hunter-gatherer populations with no evidence for outside contact that 
left any genetic mark. As such this would imply a prey route 
domestication by local hunter-gatherer populations. This is actually 
quite rare and its only clear parallel is reindeer domestication. 
Reindeer are also animals that were hunted by relict Palaeolithic-
derived populations, but can also be ridden and milked. Indeed the 
close cosmological parallels between reindeer herders and hunters 
have been noted. One can envisage a very similar process at Botai by 
hunter-gatherers with similar ancestry, relating to animals that can 
perform similar functions. Whilst reindeer are common to the taiga, 
horses are common to the more southerly forest steppes. It now 
seems, when considering the human and horse ancient genomic data 
together, that there was a significant population replacement, dating 
to the middle Bronze Age, that saw peoples like the Botai and their 
local horse stock, eventually replaced by groups migrating from the 
West with their own horse. 

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