From crusties to people

On Twitter, edenchanges asked:

I'm curious - do you map across your conclusions based on the crustaceans to humans?

I appreciated the question, and thought it deserved a more substantive response than what I can do in 140 characters.

The kind of research questions that interest me are, “How do you get new behaviours over evolutionary time? How do you lose behaviours? How do the nervous systems change as behaviours evolve, and vice versa?”

Those questions have nothing to do with crustaceans. They’re general questions about evolutionary biology and zoology. I could, I suppose, work with those questions in other kinds of organisms. So in that sense, I can connect what I do with crustaceans to humans. Over at my Marmorkrebs blog, I have an occasional series of posts called, “Great moments in crayfish research,” and some of those posts talk about some of the things we’ve learned from crustaceans that have turn out to be widely applicable (e.g., electrical synapses).

That said, it’s really, really hard for me to do.

The way I tackle questions is different than the way a vertebrate neurobiologist tackles questions. The difference between crustacean neurobiology and vertebrate neurobiology is like the difference between a psychologist and a sociologist. A psychologist is more likely to be concerned with individuals. A sociologist is more likely to be concerned with demographics, societal trends, and factors emerging from huge groups of individuals. I get to know neurons one by one and learn their names. A vertebrate neurobiologist looks at entire nations of neurons but is rarely concerned with how the actions of one specific individual neuron, except as one is representative of larger classes of neurons.

Second, it’s fun to generalize, but it’s not always a good idea. People study fighting in crayfish. In crayfish, it’s an innate behaviour that seems to be kicked into overdrive by the neurochemical serotonin. It would be foolish to extrapolate from crayfish immediately to say that humans aggression is innate (which some would read to mean, “inevitable”) and that serotonin would have a special role in regulating human aggression.

Third, I am deeply opposed to the notion that the only reason to do biological research is because it has some implications for humans. (Which, to be clear, I’m not saying edenchanges was implying.) I get pissed when I hear almost every interview on the Science podcast end with some variation of, “Are there any practical applications?” or “Could these findings be applied to humans?” My take is similar to Richard Feynman, though I would replace “physics” with “research” in this quote:

Physics is like sex. Sure, it may give some practical results, but that’s not why we do it.

I don’t do research on crustaceans to learn something about humans. I do research because it is inherently interesting, because it uncovers beauty, and because knowledge is better than ignorance.