Fellows Feature: Sharon Greenblum

Sharon Greenblum is a CEHG postdoctoral fellow in the lab of Dmitri Petrov. She is a graduate of Northwestern University (BS, Biomedical Engineering) and the University of Washington (PhD, Genome Sciences). Her research focuses on studying rapid adaptation in response to natural environmental and ecological change, primarily using Drosophila melanogaster as a model organism.

Can you tell us a bit about yourself, personally and professionally? 

I am a postdoc in Dmitri Petrov’s lab, currently studying the dynamics of rapid adaptation. I grew up in Maryland, but have lived in quite a few places since then, including Chicago, Copenhagen, Washington DC, Tel Aviv, and Seattle.

My path through science has been a bit all over the map as well. I started out studying biomedical engineering as an undergrad at Northwestern University, interested especially in the mechanics of the human body, and what a model of how a knee bends or how a lung inflates can tell us about the course of human history and the challenges our species has found solutions to over time.

My junior year of college, eager to escape another brutal Chicago winter, I decided to study abroad. Though the basis of that plan backfired slightly – Copenhagen in January is no springtime in Paris – academically, it was a real turning point. I completed a course in Bioinformatics, which got me started on the more molecular track I’ve followed ever since. After college, I did a two-year fellowship at the National Institutes of Health, working in a bioinformatics lab studying the molecular pathways implicated in different cancer subtypes. I decided then that I would really benefit from a solid foundation in genetics, so I joined the Genome Sciences Dept. at the University of Washington for my PhD. There too, I took a leap into something new; I joined the lab of a brand new professor studying something I’d never heard of – the human microbiome. It was really exciting being part of such a fledgling field, especially one that allowed me to combine my interest in coming up with new bioinformatic techniques with my passion for understanding the complex forces that have shaped human health and history.

Why did you become a scientist? Did you want to be a scientist as a child? (tell a story)

I didn’t always want to be a scientist. When I was little (and I have the big scrawly handwritten essays to prove it), I wanted to be a librarian. At the ripe old age of eight, I was picturing myself with little pince-nez glasses and pearls. Then it was a journalist, a reporter on the front lines. Then a CIA agent. Then a National Geographic Explorer-in-Residence. Truth be told, I still want to be all of these things. Very much so. Science is the best way I know of to combine these dreams. The common thread through all of these is a desire to get beneath the surface, to understand why things work, to explore, and to ask instead of accept.

Can you tell us about your current research and what you want to achieve with it? Why is your research important? 

In Dmitri’s lab, I’m focusing on developing bioinformatics frameworks for a new way of studying evolution – one that lets us measure adaptation in real time, in real conditions, with realistic metazoan populations. The approach has been termed ‘evolve and resequence,’ and it’s an incredibly exciting step for the field of evolutionary biology. To make the most of it though, we still need to figure out the best ways to obtain the most accurate measurements, and identify meaningful and robust adaptive signatures from large-scale pooled genomic samples taken at multiple timepoints.

More specifically, we’re trying to understand how populations of fruit flies respond to changing environmental conditions over the course of a single summer. From collecting samples of wild fruit fly populations at different timepoints, Dmitri and his colleagues have found evidence that an impressive amount of genomic adaptation may be occurring within populations even at these short timescales, enabling successive fruit fly generations to become better at metabolizing resources quickly when food is abundant, for example, or surviving longer in times of food scarcity. Much of this adaptation appears to be from standing variation – alleles already found in the population that rise and fall in frequency over time.

In general, I’m really excited by the idea that experiments can move beyond the laboratory, and that we can incorporate the tempo of real life. My interest is in developing experimental and bioinformatic frameworks for modeling evolutionary dynamics derived from real biological data. I think that a deeper understanding of how populations adapt may fundamentally change our view of way evolution proceeds, and our assumptions about the timescales that are most influential.

What are your future plans?

I’d love to continue understanding evolution and the processes that govern adaptation at the molecular scale, in whatever capacity I can. More specifically, I’m hoping to spend the next few years gaining a clearer picture of evolutionary dynamics in both host and microbial contexts, so that I will be well-positioned to begin incorporating these processes into a predictive model of host-microbiome co-evolution.

This could mean running my own academic lab, but I also think that the traditional divides between academia, industry, and even the arts may continue to blur. At some point in the future, I’d love to be part of an inter-disciplinary team focused on putting the pieces together.

Were there people in particular to whom you would attribute your professional success? What is it like working with your current lab advisor and his lab?  

I owe a lot of my current research perspective to my PhD adviser, Elhanan Borenstein. When I started grad school, I was almost exclusively interested in human genetics, but had only very vague ideas about what part I wanted to study. I definitely never expected to end up studying bacteria. But when I heard Elhanan present his research ideas to the department for the first time, I was really inspired by how he was thinking outside the box, trying to tackle really ambitious questions with unique data analysis approaches, and borrowing tried and true systems biology tools but applying them in a completely new realm. A colleague and I were the very first students to join the lab, and we got invaluable training in how to think critically and creatively. I think that really shaped how I saw science – that it’s not just about what you know, or what you can measure, but the context you use to interpret it.

I’ve been at Stanford for almost a year, and working with Dmitri has definitely inspired me as well, in complementary ways. Dmitri embodies an enthusiasm for science and academic inquiry that I have yet to see matched in anyone else. He is sharp, forward-thinking, and importantly, has a never-ending drive to share the ideas that inspire him, and turn them into reality. It’s abundantly clear that Dmitri loves what he does. The ‘fun’ part of science is what keeps me going, and Dmitri provides an admirable model of how keep this at the forefront while maintaining exceptional scientific rigor and integrity.

Can you speak a bit to the role you see CEHG playing on Stanford campus?

I think CEHG is a wonderful and important organization to have on campus. I’m a big believer in the power of being able to tackle a problem from multiple perspectives, and I think CEHG offers a means to gain deeper insight into fundamental evolutionary questions by uniting labs with disparate approaches but the same goals at heart. I think one of the biggest challenges is finding ways to facilitate communication between fields with very different vocabularies (both literally and conceptually), and CEHG may provide a training ground for scientists who are better prepared in this regard going forward.

I also think that forming an umbrella organization focused on big-picture questions (rather than specific approaches) opens the door for less traditional perspectives as well. I’ve been working with CEHG to form an Arts interest group to try to look at how the questions CEHG labs focus on are reflected in and informed by art and design. It’s been really fun and fascinating so far, and I don’t think I would have had the opportunity to do this at most other institutions!

What advice would you offer to other grad students or postdocs who are considering pursuing a similar educational and career path as you? 

I’d advise other grad students to listen closely to their instincts, and be open to new possibilities. The field of genetics is so broad, and is changing so rapidly, that what seems important one day may change by the next, so concentrating too narrowly may mean you miss out on the more exciting developments. I’d advise students to try not to be intimidated by how much there is to know and keep up with though, but trust their capacity to learn and synthesize.

Trust also that every experience can be beneficial – a background made up of what interests you will give you a unique perspective going forward. Mostly, I’d advise students to just keep on going, to take opportunities to learn something new and have fun with it.

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