sex

And it's this combination, this cumulative technology, that intrigues me.

Adam takes four hours to make a spear and three hours to make an axe.

But if you have a sexual species, then it's possible for an individual to inherit both mutations from different lineages.

They were a highly cooperative species.

The Tasmanians were isolated.

Because through the cloud, through crowd sourcing, through the bottom-up world that we've created, where not just the elites, but everybody is able to have their ideas and make them meet and mate, we are surely accelerating the rate of innovation.

Well, you look at modern hunter gatherers like aboriginals, who quarried for stone axes at a place called Mt. Isa, which was a quarry owned by the Kalkadoon tribe.

It was self-sufficiency.

In all hunter-gatherer societies today, there's a foraging division of labor between, on the whole, hunting males and gathering females.

But the difference is that these cultures never expand, never grow, never accumulate, never become combinatorial.

Because through the cloud, through crowd sourcing, through the bottom-up world that we've created, where not just the elites, but everybody is able to have their ideas and make them meet and mate, we are surely accelerating the rate of innovation.

When I was a student here in Oxford in the 1970s, the future of the world was bleak.

That is prosperity, the saving of time in satisfying your needs.

I am of course quoting from a famous essay by Leonard Read, the economist in the 1950s, called "I, Pencil" in which he wrote about how a pencil came to be made, and how nobody knows even how to make a pencil, because the people who assemble it don't know how to mine graphite.

(Laughter) And astonishingly, if you look at what actually happened in my lifetime, the average per-capita income of the average person on the planet, in real terms, adjusted for inflation, has tripled.

It's not confined to its own lineage.

And it's this combination, this cumulative technology, that intrigues me.

If you had to start from scratch, let's say you go out into the countryside.

But if you have a sexual species, then it's possible for an individual to inherit both mutations from different lineages.

In all hunter-gatherer societies today, there's a foraging division of labor between, on the whole, hunting males and gathering females.

And she doesn't have to go on an exhausting hunt and try and kill a warthog.

But there's a distinction between specialized roles between males and females.

And the consequence was that stone axes ended up over a large part of Australia.