Tuesday, February 25, 2014

How I became an evolutionary biologist

I was asked on twitter last week how I decided to study evolutionary biology, and what actually motivates my research. The story is a bit more complicated than can be parsed in 140 character bits, so here's a slightly longer version of it (the short version as relayed in <140 characters is simply "Lenski").

When I started graduate school at the U of Oregon, I wanted to study ecological questions in large charismatic megafauna (I imagined myself roaming around the African savannah chasing elephant or rhinos. cynical viewpoint: this job is now much easier and sadder than it was 13 years ago). I started as a pre-med undergraduate motivated by a certain tv show about emergency rooms, but quickly discovered that I didn't want to go to med school. To put it bluntly, I found myself worrying about how getting a "B" on any test would kill my chances at med school. As class sizes dropped I also found myself surrounded by larger percentages of hyper-competitive students with that same "B=death" mindset. Parallel experience...I worked as an intern at Aventis making flu shots during the summers of my sophomore, junior, and senior years. The money was great, but the industry life (at that moment) didn't really click with me. I made my mind up to go to grad school for biology, with an interest in animal ecology. At this point I distinctly remember applying to Liz Hadley's lab at Stanford (and bombing a phone interview), emailing John Ford about orca research at UBC, and being denied acceptance at the University of Arizona (that last one is particularly awesome looking back). I also looked at working with Nick Gotelli at the University of Vermont. From what I could tell, Oregon offered me the best opportunities in terms of money and research experiences so I picked up and moved to the west coast. Truth be told, I was hoping that I could somehow swing a research project into the ecology of sea otters.

I was fortunate enough during my first year at Oregon to rotate through three very different labs. I had written a senior paper on zebrafish genetics (I was particularly drawn to a bunch of blood mutants with names like vampire and vlad tepes) and, despite my dreams of ecology, signed on to rotate through John Postlethwait's lab under the direction of a young postdoc named Bill Cresko. During that rotation, I found myself learning all about things like evo-devo, PCR, and fish called stickleback. There was an incredibly good zebrafish/stickleback group at UO buoyed by an IGERT program to study Evolution, Development, and Genomics. As an undergraduate it had actually never occurred to me that you could study evolutionary questions using genetics. Sure I knew that evolution was pretty solid scientifically, but I didn't have an intuitive feel for how you could design experiments within an evolutionary framework. Looking back I remember being blown away that there was a journal called "Evolution" and that you could publish about things like genetic variance in wolves. This rotation in John's lab had changed my way of thinking. That first rotation got me hooked on the power of studying genomics and evolution, but I wasn't sure I wanted to work on fish. It also dawned on me that I wasn't made for camping out in the African savannah (I'm a fan of things like lattes and daily showers) and that I wasn't completely sold on the ability to control ecological experiments (for me, too much worrying about how the environment can shift results...too much rain in one year vs. the other and whatnot and having to control with statistics post hoc). My second rotation was working with Bitty Roy on molecular typing of some kind but I couldn't get the assay to work for the life of me. My third and last rotation was with a new PI in the Institute of Molecular Biology at Oregon, Karen Guillemin working with the bacterium Helicobacter pylori. I was still fighting some psychological battles against working with bacteria given my premed and industry training, but some times you can't deny your true research interests. Even though we were all kind of learning on the job, Karen was an amazing advisor for the cadre of young scientists who joined her when she started her lab. It was a great group of people, and those interactions are largely why I grew to love science as much as I do. 

Karen wasn't directly working on evolutionary questions at that time. Her work was focused on investigating virulence factors within H. pylori as well as establishing a gnotobiotic zebrafish facility. When this third rotation started I happened to read a paper out of Rich Lenski's lab on evolution of E. coli. Like many young kids, and in addition to dreaming about chasing rhinos, I had also once dreamed about being an archeologist. Digging through history, understanding the past from what remained, it felt like one big entertaining logic puzzle. Reading Rich's paper it dawned on me that I could study genetics and evolution together in real time in bacteria. In reading further papers I found myself drawn to studying questions about horizontal gene transfer and how this affected evolutionary rates. I don't quite remember when, but there was a lightbulb moment when it dawned on me that I could use H. pylori to study how natural transformation affected rates of evolution in bacteria in real time a la Rich Lenski. I could freeze the cultures and actually measure adaptation. It was so clean an elegant and, unlike my thoughts about what I was reading in ecology*, I knew I could control many aspects of the environment. Furthermore, I was able to be co-advised by Patrick Phillips, who is completely different than Karen as an advisor but equally awesome as a mentor. Patrick works mainly on nematodes, and even tried to get me to study nematode trapping fungi as a system (almost worked!), but was also completely willing to help guide Karen and I through evolutionary experiments. They both gave me enough rope to explore, but pulled me back when I was going too far off the rails. Exactly what I needed to channel my energy in grad school.

So what draws me to study evolution? Being able to hold adaptive potential within your hand. Not knowing exactly how different populations will play out, but knowing that adaptation will occur. The lure of letting nature tell you what's going on at both molecular and genetic levels...experimental evolution is a great way to figure out new ways that proteins function or interact! Studying evolution within bacteria enables me to ask a variety of questions and constantly be amazed and surprised (and at least in some cases in bacteria to perform those experiments overnight). Once you understand how evolution works, you see interesting questions in every research area. While it took me a while to convince myself of my true research calling, I can't imagine it being any different now.

*Two points to be made here in a prologue A: Please don't read this as a slight ecologists. I respect the hell out of everyone that studies ecological questions, I'm just not wired to do that kind of research full time B: I learned quickly that "control" is relative in the context of growing bacteria

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