Hello everyone and welcome to the Mindscape Podcast. I'm your host Sean Carroll.

Remember when we talked about the social construction of reality? Wasn't that fun?

We contrasted this human scale way of thinking about the world, the social world,

where you make up categories and then they're based on what really happens,

but there's a lot of freedom there. We contrasted that with the physics level, right,

with the electrons and the photons, where it's pretty clear how you want to think about the pieces

out of which reality is made. But there are a lot of layers in between the physics level and the social level,

the human level, right? There's all a biology, for example.

Today we're going to dig into a puzzle, or at least an important research area within biology,

that involves exactly this. What is the right way to conceptualize the world of species and populations and evolution?

Famously Richard Dawkins in the 1970s popularized a view known as the selfish gene.

Back in the old days, in the beginning of the theory of evolution,

you might have focused on individual organisms, and imagine that these organisms wanted to reproduce their own genomes, right?

They wanted to have kids and have their genetic heritage be passed on to future generations.

Then came the math, then came a way of thinking about population genetics that pointed out that you can pass on the genes inside of you,

even without you being involved, if all of your relatives are very good at passing on genes.

So it became not only Dawkins, but other people point out that it's as if it's the genes that want to pass on their heritage,

not the individuals carrying them. In fact, you could say that the individuals are just kind of a bus, full of genes.

They're a vehicle that carries on the genes because individuals die, right?

Organisms are born, they have a life they die, less than a century for most species,

whereas the genes can live on a very, very long time being passed from generation to generation.

So surprisingly, not everyone agrees, not so surprisingly, of course. This is a complicated thing.

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