Research

Growing up in Los Angeles, I got interested in the bugs in my backyard. I obsessively raised butterflies for many years. I collected caterpillars and kept them in a jar with leaves, and waited for chrysalis to emerge. I did this compulsively, again and again. I never got tired of it.

What I love about insects is that they’re great at showing you all of life’s possibilities. When you look at insects, you get to see that they’ve arrived at the same destinations humans have via incredibly different methods. Take a swarm of honey bees making a decision about where to build a new hive, for example. It’s a decision you can liken to one of us picking a new place to live. But the bees are making this incredibly complicated decision without our incredibly massive brain. So figuring out how insects can work using such vastly different tools is really stimulating in terms of thinking about evolution.

People tend to think of insects as these automatons, or robots, driven only by instinct. But one of the things we’ve been finding out from our research is that they are actually incredibly flexible. They can learn things. They can change their behavior based on their environment. So on the evolutionary continuum, you can’t put insects in one pile and humans in another. And even though people identify with chimps because they look like humans or New Caledonian crows because they make tools, that doesn’t mean they go in the pile with humans. It’s useless to try to draw these lines of demarcation. In evolution, there’s a complex interplay between genes and the environment for all animals, all the time.

I wanted to study sexual signals and parasites. Signals from singing insects are easier to analyze than visual signals, like the design or color of butterfly wings, which might have other non-sexual purposes such as camouflage from predators. So I spent most of a summer grabbing up every singing insect I could find, looking to see if they had parasites, and trying to see how abundant they were, and ended up settling on crickets. They’re fabulous research subjects. You can hear them and measure their calls. The males call to attract their mates.

It was one of the most serendipitous, weird, science experiences of my life. We had been studying the interaction between the cricket and the fly parasite for many years, and we just stumbled on it. We found that over 20 generations of crickets, about five years, there was a shift in the in the population from having all normal wing singing crickets, to having the preponderance of crickets with a genetic mutation to their wings that makes them unable to call. It’s not a behavioral response to the parasite. It’s not that they could call but they don’t, it’s that they can’t. 

Because it highlights conflicting selection pressures. Males are selected to call more because they get more mates, but simultaneously call less because they attract the parasitic flies. Scientists since Darwin have been interested in how these evolutionary conflicts are worked out.

The silent crickets must be producing offspring, since of course there are a lot of them out there. And we know from field experiments that the mutant males take advantage of the few callers that remain by moving closer to them. Females are also mating with the mutants, so their behavior must have changed as well.

I want to study same-sex behavior in Laysan albatross in Hawaii. There’s a relatively new colony on Oahu where around a third of the pairs are female-female. They mate with males from other pairs. If both the females produce an egg, then one gets shunted aside, but the chick is cared for just as well as if they were in a female-male pair. What interests me is how it illustrates the flexibility in animal mating behavior. We think the birds are doing this because of a strong female-biased sex ratio in the population. Like the crickets responding to silence in the environment, the birds just have the capability of doing different things depending on the circumstances. So pairing with another female isn't pathological or abnormal; it just increases the likelihood of being able to reproduce that year.

People have this misconception that evolution works smoothly and continuously. As if everything goes along until a species is perfectly adapted to the environment, and then we stop, only to find, oh my god, that the environment has gone on past us. So it’s become popular to attribute all our woes to the fact that we have Stone Age genes in the space age, and so we’re not adapted to the modern environment, and we should be eating like cave people and running around barefoot.

So this is why politicians want sex with 20-year-olds, because back in the cave days they were supposed to seek out young fertile women? And why so many people seem to have these weird obsessions, like insisting they can eat sweet potatoes but not white potatoes, because of their ancestry. I think a lot of this stuff is a misapprehension of the way evolution works. So my new book is called “Paleofantasy."  It’s about how the rate of evolution really does affect what we do, but it’s not this continuous smooth process. 

One wonderful thing about the UC system is that it really does value both teaching and research. So do I. I don’t feel I’ve been someplace where people are either encouraging me to neglect the students, or encouraging me to lower my research standards. Neither has been true. It’s been a great thing for my development as a scientist.