A shepherd and a herd of goats and rams near Ardabil, Iran
Shutterstock/MAVRITSINA IRINA
Goats were domesticated as early as 10,000 years ago in the area around the Zagros mountains in what is now western Iran. The finding suggests goats were one of the first animals to be domesticated, with only dogs unambiguously preceding them.
“By 10,000 years ago, we have this lining up of archaeological and genetic data that seems to suggest that we have the first population of managed goats,” says Kevin Daly at Trinity College Dublin in Ireland.
Goats are known to have been domesticated in western Asia or eastern Europe. Archaeological evidence suggested this was underway by 8000 BC. At some sites, male goats were being selectively killed at a young age, suggesting they were being kept in pens rather than hunted in the wild. At Aşıklı Höyük in what is now Turkey, goat urine left chemical traces in the soil where the animals were kept.
Daly and his colleagues examined goat fossils preserved from two sites in the Zagros mountains: Ganj Dareh and Tepe Abdul Hosein, which have been excavated on and off for decades. They were inhabited between about 8200 and 7600 BC.
The researchers obtained DNA from preserved goat parts from both sites: 14 nuclear genomes, as well as 32 mitochondrial genomes that were only inherited from the animals’ mothers.
Daly and his team found that the goats formed two distinct groups – one was closely related to modern domestic goats, the other to modern wild goats. This means domestication had proceeded beyond the goats simply being kept. “The process of genetic domestication had already begun,” says Daly. Meanwhile, the wild-type goats were probably hunted.
“This is the earliest genetic evidence of goat domestication,” says Daly. “It’s looking more and more like the domestication of goats was probably primarily in or near the Zagros region.”
Dogs were domesticated thousands of years earlier, at least 14,000 years ago. Sheep were domesticated at around the same time as goats, but slightly further west, perhaps in what is now Turkey. Cattle and pigs were domesticated later.
Daly suggests that sheep and goats preceded cattle and pigs because they are smaller and thus easier to restrain. “Cattle are obviously much larger and more dangerous,” he says, as are wild boar.
Journal reference: PNAS, DOI: 10.1073/pnas.2100901118
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Source: Humans - newscientist.com
