Introduction
My parents are both physical geographers, which meant on family trips they always pointed out the scars of an old earth weathered over large timescales. They showed my brothers and me the basalt pillars that turned into the black, sandy beaches, toe-searingly hot in the sun, of the crater lake where we swam every summer; the huge grooves carved into the rock faces of the Alps by glaciers that long ago filled the valleys where we went hiking; the Rhine river depositing the clay once used by the brickworks in our hometown. And in the rocks that my father collected, sometimes a fossil of an animal or a plant.
I don’t remember ever not having the vague notion that, over large time scales, species become other species, or go extinct and become fossils. This is what evolution is to most people: a story of things appearing and disappearing, from trilobites to cavemen, all very long ago and neatly organized into eras that you’re supposed to memorize. Only as an undergraduate student, near graduation, did I come to realize that evolution is not actually a story: it's a process, which creates the patterns we see around us in nature.
In my research at the time I was trying to show how primates had evolved to fill up different ecological niches to various levels of specialization, thinking that there might be simple rules that underlie this. My adviser taught me to look at this diversity as the outcome of a repeated natural experiment: from a common ancestor, primate lineages had to come up with different, evolved solutions under different pressures. Or, sometimes, the same solution independently arrived at multiple times, under the same pressures. By drawing the right comparisons across combinations of solutions, the rules that led to them should reveal themselves.
Because all living and extinct species are related to one another we have to be careful with drawing comparisons among them: not every pattern that we see in nature is the result of solutions repeatedly arrived at by evolution. At least some similarities across species are the result of a solution arrived at just once, in a common ancestor, whose characteristics simply stuck around in its descendants. Where we might think there is a general rule, there’s actually just a single event that happened before the tree of life branched out further into new species.
The methods that are used to reconstruct the shape of the tree of life and to place evolutionary changes on this tree are my main scientific interest. To pursue this interest in the way that I want I have had to pick up the nerd skills that broadly have to do with how we digitally represent, describe, combine and analyze observations we make - at the level of DNA all the way to that of individuals and groups. I have so far been able to apply these techniques to interesting questions about evolution in life forms as diverse as primates, pitcher plants, snakes, tomatoes, birds, orchids, and numerous insects.
