Timothy Taylor is an anthropologist and archaeologist based at Bradford University. In his new book, The Artificial Ape, he argues that the moment our apemen ancestors began chipping at lumps of stone to create their first tools, they released a force – technology – that has played a pivotal role in shaping the human species. Such innovations have altered the way we nurture our offspring, prepare our food, use our strength and establish cultures. We did not invent technology, this 50-year-old scientist argues. Technology invented us.

So what insights do we get into human nature when we look at the role of technology in our evolution?

There is a perception that technology – from the industrial revolution to the computer age – has suddenly put us into a new world, one that is a bit scary. We worry that computers might take us over, for example. But it was ever thus. The genus Homo is a product of the realm of technology. It underpinned our evolution and turned us into a highly intelligent creature. That is why I describe Homo sapiens as an artificial ape.

When did this process begin?

We can see from the archaeological evidence that by 2.6m years, our australopithecine apemen ancestors had learned how to chip at stones and make tools. Before then, they had used stones to cut things but now they were actually shaping bits of stone to suit various uses. That was the crucial moment, the one that triggered a social revolution.

In what way?

Well, one important development would have been the construction of the first slings for carrying around newborn babies. Without them, women would have expended more biological energy carrying their children in their arms than they would have used on providing them with milk, on lactation. But now, if you had tools to make spears, you could kill animals and remove their skins with the knives you had learned how to make and [from the skins] you could make a sling with which to carry your baby.

The implications of this development were enormous. It meant that babies could continue to develop outside the womb after birth and that their brains could continue to grow. They were not constrained by the size of their mothers' pelvises and could grow bigger and bigger for years. It gave us scope for intellectual expansion. We could give birth to children who were intellectually underdeveloped but whose brains could continue to develop outside the womb.

We can only infer that, of course. The skins or viscera that might have been used as slings have long since decayed.

In addition, though, tools provided us with the weapons we used to kill animals whose meat provided the protein-rich diets that were necessary for our brains to expand over the eons. Thus technology let loose processes that led to us evolving larger and larger brains. It does not explain why we developed big brains, but it shows how technology created the space in which that expansion could occur.

We haven't looked back since then?

Well, no, not quite. In fact, brain size has decreased slightly over the past 30,000 years and I think that has a lot to do with technology. By that period in our evolution, a caveman no longer needed to remember how many mammoth tusks he was owed by another caveman. He could mark that on the walls of his cave with paint. We had reached the stage where we had learned to use symbols. So technology has recently started to take away a little of our need for large brains. Indeed, we are now outsourcing our intelligences at a greater and greater speed, with the development of powerful personal computers, for example. So I would predict that, in the long run, humans are going to continue to get less biologically intelligent. This is not necessarily a bad thing, however.

Consider the example of eyesight. On average, it is probably deteriorating for our species. If I had to survive by being able to spot a deer and then shoot it down with a bow and arrow, I probably wouldn't be here. But I can not only see deer, I can see microbes and distant galaxies – using microscopes and telescopes – because of my symbiotic relationship with technology. So in many ways my eyesight is better than a caveman's or a hunter-gatherer's, but only in terms of me being a biotechnological creature. Through that my power has extended. That is why I talk about us being the weakest ape in the innate sense but, with technology, the strongest.

Should we be worried about our growing dependence on technology?

The answer is yes or no, depending on your optimism or pessimism. It could be that in the distant future Earth will become uninhabitable for humanity and if the technology to help us leave does not exist, we may eventually succumb to a dusty death. For example, without technology, we will not have the means to deal with the next huge meteorite that heads our way. On the other hand, with technology, we might make things so unpleasant down here that we really damage the planet and render it unfit for humans. It is a very finely balanced issue.

One fact is clear though. The thing is out of the box. There is no back-to-nature solution for us. It is too late. We are going to have deal with technology and learn to take charge of it in future.

The Artificial Ape: How Technology Changed the Course of Human Evolution by Timothy Taylor is published by Palgrave Macmillan (£17.99)