This is an extract from the Our Human Story email newsletter. in your inbox every month.
STATISTICALLY, you probably live in a city. Around , and in high-income countries where New Scientist has most of its audience, the figures are even higher.
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This means you also live alongside urban animals. In the UK, where I live, the most conspicuous ones are pigeons, foxes and gulls. These species have adapted to life alongside us, often by eating the food we throw away.
Animals such as urban foxes that live alongside us, and benefit from doing so, are called synanthropes. They aren’t domesticated like dogs or cows, but they are adapted to a human-centric life. Some urban foxes have skull shapes that differ from country-dwellers and more closely match domesticated dogs. Other examples include rats and trash pandas – sorry, I mean raccoons.
It is generally thought that synanthropy began with the agricultural revolution, around 10,000 years ago. That is when people started settling down in the same place instead of moving around, and crucially when they started storing large quantities of food and accumulating rubbish.
However, it now looks like synanthropy may go back several tens of thousands of years, and other hominins like Neanderthals might have had their own synanthropic companions.
Very little research has explored the idea of synanthropic animals before the rise of agriculture, so what follows is tentative. It is based largely on the work of Chris at the University of Helsinki in Finland, who published a in April summarising what is known.
Baumann says archaeologists have assumed for decades that animals couldn’t form synanthropic associations with hunter-gatherer communities. Without permanent settlements with waste food and refuse heaps, how would synanthropic animals support themselves?
However, hunter-gatherers on the go could provide a niche for animals if they produced enough waste. The evidence for this all comes from Europe. In a , Baumann showed foxes in south-west Germany began eating a more restricted diet dominated by reindeer around 42,000 years ago – not long after modern humans arrived in the area.
Similarly, in the Czech Republic there are a number of mammoth kill sites where tons of mammoth bones from between 30,000 and 25,000 years ago are preserved. Raven bones at the sites contain telltale chemicals, revealing that they ate a lot of mammoth.
“When humans hunt large herbivores there’s a lot of waste,” says Baumann. “They will not eat everything.” It seems the foxes and ravens got the scraps.
Why did early Europeans tolerate foxes and ravens eating their leftovers? Baumann points out they didn’t pose a threat, so there was little incentive to drive them off. Furthermore, by eating the scraps, the foxes and ravens may have reduced the incentives for larger carnivores like wolves to come scavenging, which would have threatened the humans.
In some of the sites, people collected fox teeth and raven feathers, perhaps for clothing or jewellery – suggesting that they valued the animals’ presence.
How widespread were these palaeo-synanthropies? The short answer is we don’t know. The European evidence is limited to just part of the continent and the last 42,000 years, where studies have been done. Baumann suspects palaeo-synanthropies were older and more widespread, but he needs direct evidence.
Conceivably, only modern humans changed their local environments enough to attract animals like foxes. In that case, the interaction may have developed in Africa and then spread to other continents when our species did.
Alternatively, synanthropies may have formed whenever hominins had a large ecological footprint. Baumann has plans to explore sites in France that were heavily used by Neanderthals, and which also have the remains of foxes and ravens.
Without more information, it is hard to say what this means for the origins of domesticated species. Baumann says some animals may have become domesticated this way, such as cats, who preyed on the mice eating our grain. In contrast, livestock animals like cows were probably deliberately corralled by humans. He also doubts wolves could have been domesticated into dogs through synanthropy, because wild wolves posed a real threat to Stone Age people.
Synanthropic species occupy a nebulous position today. Many of us perceive them as pests, but maybe the knowledge of palaeo-synanthropies will help us get a bit of perspective. Our relationship with foxes, we now know, goes back at least 40,000 years – four times as long as we have had domesticated cats, livestock and crops. Maybe we could, at some point, get used to them.
Mike’s week
What I’m reading
The Song Rising, the third of Samantha Shannon’s twisty urban fantasies set in a totalitarian London.
What I’m watching
Everyone says Top Gun: Maverick is a masterpiece of escapist cinema, but no film that wastes Jennifer Connelly is a masterpiece.
What I’m working on
In order to remind you all that the life of a reporter is one of glamour, I’m researching sewage.
Michael Marshall is a science writer based in Devon, UK. He writes New Scientist’s monthly email newsletter about human evolution, Our Human Story. His book The Genesis Quest is about the origin of life on Earth and is now available in paperback.
