Fascinating two part interview with Bert Hoelldobler, a leader in superorganism studies at Arizona State University - here & here:
A few years ago, I decided to fry up a mess of smallmouth bass from my parents’ pond. But when we — okay, my mom — started to clean the fish, they were full of parasites. After identifying them (thank you, Maine Fish & Wildlife Service!) I hopped online to learn more about the parasites. What I found was amazing.
The parasites, known as yellow grubs, have a very circuitous life cycle. The eggs are passed into the water by fish-eating birds like heron, then picked up by fish. The more parasites that infest a fish, the more likely it is to swim near the surface — making it more likely to be eaten by a bird, inside of which the parasites lay their eggs. And so the cycle of parasite life continues.
What caught my attention was the relationship between parasite population density and the odds of a fish being eaten. Clearly, natural selection favored those parasites whose interactions caused the fish to adopt the riskiest behaviors — but I’d always thought of evolution as a process that operated on individual adaptations, rather than group behaviors.
Talking with scientists, I learned that group selection is central to the storied, sometimes controversial field of superorganism theory, in which a population of creatures can be seen not as a collection of disparate individuals but as a high-level organism unto itself.
A few years ago, I decided to fry up a mess of smallmouth bass from my parents’ pond. But when we — okay, my mom — started to clean the fish, they were full of parasites. After identifying them (thank you, Maine Fish & Wildlife Service!) I hopped online to learn more about the parasites. What I found was amazing.
The parasites, known as yellow grubs, have a very circuitous life cycle. The eggs are passed into the water by fish-eating birds like heron, then picked up by fish. The more parasites that infest a fish, the more likely it is to swim near the surface — making it more likely to be eaten by a bird, inside of which the parasites lay their eggs. And so the cycle of parasite life continues.
What caught my attention was the relationship between parasite population density and the odds of a fish being eaten. Clearly, natural selection favored those parasites whose interactions caused the fish to adopt the riskiest behaviors — but I’d always thought of evolution as a process that operated on individual adaptations, rather than group behaviors.
Talking with scientists, I learned that group selection is central to the storied, sometimes controversial field of superorganism theory, in which a population of creatures can be seen not as a collection of disparate individuals but as a high-level organism unto itself.
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