Current Research
Social epistasis
How do biological mutualisms get started in the first place? Once two entities start to connect, why might they continue dancing together, ultimately spinning off into a world of one?
From the mitochondria in your cells to the bacteria in your gut, YOU are a walking mutualism. If you were blended up and 100 random cells were chosen from the goo, only about 10 would be human. I think the Self is fundamentally plural, too.
My current project uses an engineered yeast mutualism to test for social epistasis. Strain A and Strain B require each other, and the duo can evolve to withstand greater dilutions than the ancestor pair was able to withstand. I want to see to what extent A and B's evolutionary trajectories are contingent on the other's; if I evolve several AB systems, how well will each individual strain do with separately-evolved partners?
Group hunting in animals
One lion hunting alone will catch a gazelle about 15% of the time. Two lions hunting together: 30%. Three or more lions? Still 30%. So why do lions group hunt in the first place?
I'm currently working with Nathan Mhyrvold, a serious fan of charismatic megafauna (like attracts like?), to model how costs of group hunting affect expected pack size.
On The Backburner
Bacteria and bacteriophage coevolution: How does ecology affect evolution?
In general, there is an unfortunate trade-off between using your environment and improving your environment. Bacteriophages must infect and kill their hosts to reproduce, but in doing so, they force their progeny to face fewer and increasingly-resistant hosts. Prior work has shown that reproductive restraint is evolutionarily favored when migration is local (moving next door) as opposed to global (moving randomly in the world) - though this work did not allow resistant hosts to evolve.
T7 viruses still break into their cellular hosts, but many viruses have found a sneakier way. These lazy criminals never leave their hosts at all, but have integrated into the host DNA, and quietly stay along for the ride. The remnants of these viruses comprise about 8% of the human genome, compared with just 1% that codes for human genes.
We have repeated this experiment allowing host resistance to evolve at high cost, and repeated it again allowing host resistance to evolve at low cost. An arms race has played out in these new experiments, as hosts evolve resistance and phages respond by evolving themselves. We are currently assaying the evolved strains to see what traits are consistently found in which ecologies.
Other Topics
Information Theory. My interest in game theory has been largely rekindled by Carl Bergstrom, and I hope to join him in examining the evolution of information signaling.
"The walking stick serves the purpose of an advertisement that the bearer's hands are employed otherwise than in useful effort, and it therefore has utility as an evidence of leisure."
Thorstein Veblen, 1899
Ethics. Recreational hunters outnumber vegetarians in our biology department. I find the discord between anthropocentric and biocentric conservationists fascinating, and would like to compare various ethical foundations of wildlife conservation. I am also intersted in the poorly-monikered 'leaky pipeline' metaphor, in which women 'leak' out of the academic pipeline.
"Penguins are only important because people enjoy seeing them walk about on rocks... I have no interest in preserving penguins for their own sake."
William Baxter, 1974
Motivation
Organisms change their environments, for better or worse. And the organisms themselves are evolving to suit the environments they are affecting - plants had to evolve to survive the oxygen atmosphere they were creating. The organism-environment divide gets murky., and the evolution of the system gets unpredictable very quickly.
Worse yet, the "environment" is often other organisms - the plants you eat, the coral that provides shelter, the fellow yous that are competing for resources - and they're evolving themselves. From this huge uncertain network, can we make evolutionary predictions of social dynamics?
Nazca boobies lay two eggs. Should both eggs hatch, the siblings go head to head in a sumo-wrestling death match - the first chick pushed out of the nest is ignored by the parents, and inevitably dies. (Three cheers for Mom and Dad, who fed me even though I was no match for Joshua.) A 2008 paper concluded that "Nazca boobies experience life-long consequences of androgenic preparation for an early battle to the death." How could this evolve?
Publications and Presentations
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