a brief history of the superorganism

Wired | Evolutionary biologist and superorganism pioneer Bert Hoelldobler talked to me about the history of superorganism theory. Part 1 of the interview is here, and here’s the rest:

Leafcutter ants make unbelievable nest structures. They have castles underground that go eight meters deep, that have a surface of about 50 square meters, and all sort of channels, chambers. It’s a beautifully constructed piece of art, and not one ant would be able to do this; this is an emergent structure of interactions that follow certain rules of thumb that we don’t understand yet. Almost as complicated as the brain. Put a couple million individuals — tiny little brains — together, and they interact according to certain rules that create an emergent pattern. The end result is these fantastic nests. And not only that, these collectives of little brains — if you take a picture of the brain, a brain consists of a couple million or billion neurons. The members of an ant colony [are neurons that form] a little brain. These are millions of brains connected in a way we don’t understand yet.

It’s as exciting as understanding the pattern of a brain. We try to understand the connections of these millions of ants that creates this caste system, complex communicaiton and foraging and territorial strategies, and it’s all done by these interactions. When you look at these things, you can’t avoid saying, at this stage an insect colony functions like an organism. A superorganism. And you can go forward and say, this is an extended phenotype: selection doesn’t work on individual level, but on the whole colony.

If you have in a population many colonies of same species, they compete with each other like solitary animals competing with one another. The colony which has a slightly better communication system to bring in limited resources, and if this slight difference has a genetic basis, that colony will reproduce faster than the neighboring colony, and the gene — the allele that codes for a slightly better communication system — will spread faster than the alleles of the neighboring colony. The phenotype is the colony, shaped by this selection. Of course, it is in the end the gene carried by the queen, the male, that spreads, and the workers are the extended phenotype which, because of their particular adapatation, will affect the spread of these genes.

When we look at how selection shapes things, we had to realize that it didn’t help us to take a purely gene perspective, like Richard Dawkins. Not that he’s wrong, but it doesn’t say as much about how selection works. Multi-level selection isn’t new, it was already proposed in the seventies, but we’ve worked it out more. The colony in the leafcutter or army ants is a major target of selection.

Not all ant societies are like this. They’re not full superorganisms. Ed Wilson sees this for all ants; I don’t. There are phylogenetically primitive ants, not so evolved as leafcutters, and they have internal friction — fights for reproduction privileges. They have superorganism traits, but I wouldn’t call them true superorganisms, as there’s a lot of selection going on at the individual level in the community. They haven’t reached point where in-colony conflict is gone and it’s now between-colony.

People ask, why aren’t all ants now superorganisms? Why do they all still show these ancestral traits? Very simple: they haven’t changed much. They fit into a particular niche.

So do we learn from this about humans? I’m very careful, because human society is a society built on a cultural fundamental basis. But there are biological rules to our social behavior: no question. We are one of the few species to evolve social systems. What is common in all these social systems is a division of labor; and once this was evolutionarily rendered, it became incredibly successful. This is true for almost any society: once they reach a high division of labor, they have enormous successes due to division of labor. And the second thing, once a society becomes almost like an organism, it becomes very tightly interconnected.

In our early past, in our still-biological past, 15,000 years ago we were hunter gatherers. We showed group cohesiveness and discrimination against other groups. It was adaptive. It was quite understandable that we evolved traits of group recognition, and making sure we recognized foreigners. This is my conviction that this is probably the early basis for our unfortunate xenophobic behavior that is still in us. It’s a behavior that is now terribly maladaptive. I keep always citing David Hume — that just because there is an atavistic trait in us, it doesn’t justify that we live it.