Gray Wolf
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Hello, and welcome to Our Human Story, New Scientist’s monthly newsletter all about human evolution and the origin of our species. To receive this free monthly newsletter in your inbox, sign up here.
This month, prompted by the arrival of our family’s new kitten Peggy, I’m gently pawing at humanity’s relationship with animals. In recent years, we’ve learned a lot about when and where different species were domesticated – but to me this just raises even more questions.
Animal friends
It’s a truism that humans have exerted an outsized influence on the natural world. We have domesticated dozens of animals and plants. There are the familiar examples like cats, chickens and maize, but also many that aren’t so familiar in the Western world, like the dozens of crops domesticated by farmers (if that is exactly the right word) in the Amazon rainforest over millennia.
As with many aspects of prehistory, the more we learn, the older domestication looks. Until relatively recently, it was thought that every domestication took place within the past 11,000 years. This period is known as the Holocene, when the climate has been relatively stable and when some humans took up habits like sedentary farming, urban living and writing. But one domestication preceded it: dogs.
We still haven’t pinned down when and where this happened, but dogs were being buried alongside people as if they were pets at least around 14,000 years ago, and they may have split from wolves up to 40,000 years ago. There was possibly more than one domestication event, with only some leaving living descendants. But what’s clear is that it was pre-Holocene and before the advent of permanent settled farming. It may have begun with a form of cooperative hunting.
Set against this are the many clear examples of domestication during the Holocene. For example, I recently wrote about a massive genetic study of horses, which showed that modern domestic horses are descended from a population that lived in what is now Russia, around the Volga and Don rivers, about 4200 years ago. The domestication may have begun a little earlier, but only by a few centuries.
How can we explain why domestication happened so late?
Fascinated by beasts
This holds true across Europe – where most studies of cave art have been done – and elsewhere in the world, including Indonesia. Ancient painters spent enormous effort portraying animals in a realistic way. But they couldn’t be bothered with illustrating people: when people are depicted in cave art, they’re rarely better than stick figures.
In a sense, the absence of people in the art is the more mysterious bit. Why weren’t people interested in depicting each other?
Most cultures place enormous symbolic importance on animals. Think of English lions (even though there haven’t been wild lions in Britain for millennia), American eagles and the many versions of “familiars” and “were-animals” that have arisen in cultures all over the world. Think of the rabbits of Watership Down, Anansi the West African spider god, and the ancient Egyptian worship of cats.
It’s almost too easy to think of reasons why prehistoric people were interested in animals. First, humans and our ancestors have been eating meat for a very long time. Exactly when we started is contentious, but we’ve certainly been at it for hundreds of thousands of years. This must have required an enormous amount of knowledge: of the animals’ movements, their behaviours, how they defended themselves. To make a success of their lifestyle, prehistoric people had to take a keen interest in animals.
Similarly, plenty of animals posed a danger. Predators like cave bears and sabre-toothed cats are just the most obvious. There are also inherent dangers from massive herbivores like mammoths and giant ground sloths: even if they don’t want to eat you, they can still trample you.
I’ve been reading John Bradshaw’s The Animals Among Us, and he argues that understanding animals is as profoundly human as language or self-reflection. I think he might be right. The capacity and urge to understand animals, to predict what they will do and even manage their behaviour, is an ancient one.
Wild domestication
The more I think about domestication, the more I’m baffled at how late it happened. Our species has existed for something like 300,000 years, and other hominins like Neanderthals were similarly skilled at dealing with animals. Why weren’t dogs domesticated 100,000 years ago, or even earlier?
I don’t think it is a matter of intelligence. The fact is that domestication doesn’t require unusual foresight or brainpower. If it did, it wouldn’t happen in the natural world. Think of the many ants that have domesticated other species. There are ants that plant seeds, cultivate fungus, “milk” aphids for sugary liquid or even farm other animals for meat. I very much doubt that the ancestral ants had any kind of plan for this. Instead, I think that the species involved found advantages in living together and gradually adapted over many generations. If ants can domesticate other species in this unconscious, gradual way, so could prehistoric people. Why didn’t they?
I don’t have a firm answer for this, but I do have a tentative thought. It’s a curious fact that not many animals were domesticated in the Americas, compared with Eurasia and Africa. Llamas and alpacas are almost the only ones. A lot of ink has been spilled, for instance in Jared Diamond’s Guns, Germs and Steel, trying to work out why American animals were so resistant to domestication. I wonder if it’s because people hadn’t been living there as long. There have been hominins in Eurasia and Africa for millions of years, but people only made it to the Americas in the past few tens of thousands of years. Maybe the animals in Eurasia and Africa had simply had longer to adapt to the two-legged apes in their midst, priming them to be domesticated. The American animals had a shorter history with people.
In other words, I think the reason most domestications happened in the past 10,000 years isn’t because people only then thought of it, but because species need to co-exist for a long time before they can form such close relationships. My colleague Krista Charles recently reported that wolf puppies raised by humans become just as close to their carers as dog puppies. Wolves are still wild animals, yet they can form relationships with us that most animals can’t.
I’m pretty sure this doesn’t make sense of everything. It does seem like a gigantic coincidence that so many domestications happened in the past 10,000 years, but I’m very uncertain as to why. A particular problem is that domestications happened for different reasons: dogs seem to have been helping us hunt, while horses may have first been domesticated for their milk. So, it may be a mistake to look for a single overarching explanation.
To see what I mean, take the baffling example of tobacco (baffling to me anyway as I’ve always absolutely hated the smell). We recently learned that people were using tobacco at least 12,300 years ago. That’s millennia before the plant became domesticated. It has no nutritional value and doesn’t even give you interesting hallucinations – but people smoked it anyway.
Don’t miss this story
Ettore Mazza
Ettore Mazza
A new hominin species has been named – but it may not stick. Researchers led by Mirjana Roksandic have proposed Homo bodoensis as a new name for a bunch of African fossils that lived hundreds of thousands of years ago in the Middle Pleistocene. This is a particularly confusing period of human evolution: there were several species co-existing, and many of the fossils are hard to classify, so we don’t know how widespread each species was, how long it lasted, or which species gave rise to which others. It’s all a bit of a muddle. H. bodoensis is meant to be an umbrella term for all the African hominins with big brains that were alive at the time. It has the advantage of simplicity – and the reference to the Bodo cranium discovered in Ethiopia makes it an African name, which I think is a good thing. However, the rules of nomenclature say that the earliest species names have priority, and several of the fossils in question have already been given names.
From the archive
The ancient Maya culture is one of the most fascinating in archaeology. It’s surprising to me that there are so few depictions of the Maya in books and film, at least in the English language. The Maya were one of the most technologically advanced cultures in the Americas for hundreds of years. They had writing and drew accurate astronomical tables, planted orchards of nut trees, created vivid blue dyes, and built vast cities. Archaeologically, the most conspicuous things are the enormous monuments they built – more of which are found every year. Around AD 800, the Maya stopped building monuments and this has been interpreted as a collapse of the civilisation, probably fuelled by an intense drought. I think it’s more correct to say that the Mayan social structure collapsed – that is, the elites were deposed. It wasn’t that everybody died so much as there was a revolution.
Also in New Scientist
1. Tatanka Iyotake, popularly known as Sitting Bull, was one of the most famous Native American leaders – and a new DNA study adds to evidence that he has living descendants.
2. We now know that Vikings were in North America in the year AD 1021, exactly 1000 years ago – although they might have arrived even earlier.
3. Iron Age miners ate blue cheese and drank beer, according to a study of their faeces.
See you next month!
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Source: Humans - newscientist.com
