Domestication of Goats in Iran Was Earlier Than Thought

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A goat in Colombia. Humans and goats have been living side-by-side for at least 10,000 years. Or more.
A goat in Colombia. Humans and goats have been living side-by-side for at least 10,000 years. Or more.Credit: Petruss
Ruth Schuster
Ruth Schuster

Goats. The more spry members of the species can climb trees despite being hooved, and archaeology has proven that goats have lived cheek to jowl with us for over 10,000 years. Yes, despite their smell and the oddly-shaped pupils that inspire absurd demonic associations, goats were among the first animals to be domesticated, leaving the dog out of it.

Now, a genetic analysis of goat remains in two Neolithic sites in Iran, published in PNAS by Kevin Daly of Trinity college Dublin and a large international team, suggests that the goat has been our edible friend for centuries longer than previously thought.

The researchers also found indications at the two sites, Ganj Dareh and Tepe Abdul Hosein, that in the beginning, we didn’t just keep the animals near and dear. We “managed the herd,” which is a euphemism for selectively killing the males.

Does all this mean that goats were actually domesticated centuries earlier than had been thought, say, for the sake of argument, 11,000 years ago, and that Iran was ground zero?

Enter the goat

We humans evolved as hunter-gatherers, emphasis on hunter. Some believe that the key impetus behind the development of agriculture was the invention of beer. Others think that the real push came after we drove the megafauna into extinction, and therefore, needed new sources of sustenance.

Be that as it may, there are signs of early cereal cultivation in Israel as far back as 23,000 years ago. Clearly by 12,000 to 11,000 years ago the domestication of certain crops and animals was emerging in the Fertile Crescent. By approximately 9,500 years ago, the region had agriculture-based economies and fixed settlements.

Goats up a tree. Despite their hooves, goats are extremely agile climbers.Credit: www.twin-loc.fr

But the Zagros mountain range specifically had long been considered a sort of backwater in the Neolithic: “slow to receive and embrace domesticates and food-producing technologies from farther west,” as the authors explain.

On the contrary, it may have been this very area in Iran where goats and certain crops were first domesticated. Or it could have taken place in Anatolia, Turkey. Or in both. There is evidence in both directions, as we shall see. It could also be that this development of husbanded animals was happening in the Levant, including in Jordan and Israel.

Shut the gate

The sites of Ganj Dareh and Tepe Abdul Hosein in the Zagros range showcase human social development in the sense that they exhibit the development of sedentarism. These settlements were continuously occupied for hundreds of years, archaeologists say.

That was a change from the lifestyle of briefly-occupied camps typical to the region in the Early Neolithic until around 10,500 years ago. These camps have the hallmarks of hunting sites, Daly observes, and they show no signs of having kept “captive” herbivores.

Indentation of several goat hooves in a brick from the archaeological site of Ganj Dareh.Credit: The 'Tracking Cultural and Environmental Change project'

The people dwelling in these camps also had a relationship with the goat, but they were hunting wild bezoar ibexes.

By the time of the settlements at Ganj Dareh and Tepe Abdul Hosein, people were building permanent mud-brick homes. As has apparently been the case since the time of Homo erectus, they ate a lot of meat – chiefly goats.

Archaeologically, the goats in these two Early Neolithic settlements have been radio-carbon dated to 10,200 to 9,600 years ago. Morphologically, they look just like the wild goats: they show no external signs of domestication such as having smaller horns than their wild relatives. Morprohological domestication effects were observed after about a thousand years.

But the genetic study shows that this lookalike bezoar had already become a different animal. It was a genetically distinct goat, a new variant, and the people may have been building “homes” for them too. There are indications, based on dung remains, that goats were kept within settlements or even perhaps brought into the home, Daly explains.

So it seems that the process of domestication that turned the wild long-horned bezoar into the still-crabby but shorter-horned goat of today began well before 10,200 years ago. How these early goats were herded, whether they were walled in or kept tethered, for instance, is not known. But if by 10,200 years ago the goats were genetically distinct from their ancestral bezoar, they had already been somehow controlled for hundreds of years. Frankly, it is easier to shut a gate than to stalk an animal that evolved to climb sheer cliffs.

Wild goats enjoying some recreational rock climbing.Credit: Philip Halling / Wild goats, Val

There’s a creepy reason that lets us deduce that people living in mud-brick homes over 10,000 years ago were managing the herd: the cull.

Kill the males

If there’s one thing we seem to have retained from the earliest fathers of goat-farming, it’s “herd management,” based on the demographic profile of the two sites’ goats.

Now, when one has to feed the family by hunting and one has a spear or arrows and is not in danger of being gored by an enraged tethered creature, one naturally aims for adult male goats. They are bigger than the lady goats because of sexual dimorphism. But when one is keeping goats captive, their character comes into play.

Bucks and does may reach puberty as early as four months of age, depending on the state of their health, among other things. But reaching full bodily maturity takes rather more time and today’s goat farmers kill most of the males at 1.2 to two years of age, leaving a few alive for breeding purposes. They do that on the grounds of “herd security”, which is a euphemism for preventing goat-on-goat violence or maximizing resources. One only needs a few males to breed and the rest can be eaten, Daly points out.

Today’s farmers keep all the lady goats until they pass peak reproductive years. Goats are not known to be among the animals that suffer from menopause, though some cetaceans do. But by about the age of eight to 12, the nanny’s fertility wanes.

With this, the modern farmers are maintaining an ancient practice. The archaeologists estimate that at Ganj Dareh only 20% of the goats reached more than four years. The animals survived a tad longer at Tele Abdul Hosein, but not by much.

The survivors were usually female. At Ganj Dareh, between 60% and 70% of males were killed before reaching age two and a half years, while only 30% to 40% of females died young.

The team also noted the high diversity of the mitochondrial DNA, which comes from the mother, and of the non-sex chromosomes – but limited diversity of the Y-chromosome lineage. Not many fathers. The males were selectively killed.

Meanwhile, in Anatolia

Clearly the Zagros mountains were a site of early goat domestication, but is this ground zero? One snag is indications of goat management in Anatolia as early as 10,500 years ago, and the presence of proper goats, not ibexes, in Cyprus from 10,000 years ago.

We might know in a decade or two based on more archaeological and genetic information, Daly says. “Based on what we know now, at roughly the same time we have evidence of herd keeping in Asikli Hoyuk, Anatolia – mostly of sheep,” he points out. They had some goats too, he adds.

Couldn’t that support the argument that ground zero for the goat subspecies was Anatolia?

Well, the genetic evidence gleaned so far suggests that the root of the Iranian goats is the Zagros area but we have zero evidence for the first Anatolian goat because of sites lost to dam construction, Daly explains.

It is clear that a bit later, between 10,000 to 8,000 years ago, the Anatolian bezoar, which is distinct from the Iranian bezoar, contributed to the goat we know today.

The wild and crusty Bezoar IbexCredit: Alexander Malkhasyan / Alik Malk

The bottom line is that it is possible that herding, and the evolution of the wild and crusty bezoar into the tamed and testy goat may have slowly developed in Anatolia, Zagros and the Levant. Back then borders were not a thing and thinking in terms of a single area or event in time might not be the best way to think of the origins of the domestic goat, Daly sums up.

Moving on thousands of years, the goat would become a sacrificial offering on Yom Kippur, with one unfortunate animal being dedicated to god and another to the demon Azazel. Neither would survive this ordeal. The goat may have gained dubious fame as the model for the therianthropic god Pan’s head adornment and lower limbs, but today cheesy movies depict the devil using goat horns and feet. Time has not been kind to the caprinae.

An Alpine Ibex shows off her agility.Credit: Mathieu Despont / Martouf

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