Rohan Mehta is a CEHG graduate fellow in Noah Rosenberg’s Lab. He is a graduate of the University of California, San Diego. His research is focused on theoretical population genetics, with a specific interest in the effect of evolutionary processes on the genealogies of genes.
Can you tell us a bit about yourself, personally and professionally?
I was born in Rochester, New York, but my family moved to southern California after a year and I grew up in Irvine. I went to college at the University of California, San Diego, so I have spent the vast majority of my life in California. At UCSD, I majored in both biology and mathematics and worked in a few different labs in the biology department. I am now finishing up my PhD in Noah Rosenberg’s lab here at Stanford, working on problems in theoretical population genetics.
How did you end up here? How did you first become interested in genetics and science?
I decided that I wanted to be a scientist from a very early age, though the specific kind of scientist changed a lot over the years. I’d always check out the same few books from the local library: a book on astronomy (I loved the renderings of stars); a book on chemistry (I loved the renderings of salts and crystals); and a book on fossils (I loved the renderings of ancient ecological communities). These books turned out to be quite prescient, as I started out wanting to be an astronomer, then a chemist, then finally a biologist.
The particular part of me that made me want to be a scientist was the part that was totally in awe of how cool every little thing was, if you really think about it–from the amazing diversity of life to the constructive power of chemical reactions to the sheer vastness of space. This is the part of me that is also drawn towards mathematics; there are underlying patterns and structures in everything, and all we need to do is find them.
I appear to have parked my drive to understand the phenomena of the natural world in the field of biology, specifically in the study of evolution. I am drawn to evolution because it is the fundamental process behind all of biology and because it is the key to understanding the patterns that we see in living systems. And if evolution is the key, then, for me, at least right now, that key is made out of population genetics.
Can you tell us about your current research and what you hope to achieve with it?
My research is in the field of population genetics, focusing on an approach to studying the process of biological evolution and analyzing the genetic variation of a population and how that variation changes as a result of the forces of evolution. Most of my research has focused on the topic of gene genealogies: the ancestor-descendant relationships between individual genes. Every copy of a gene that you have is descended from some copy of that gene in your parents, and it turns out that the relationships between the individual genes in many people follow some very predictable patterns that we can use to try to figure out what happened to a population in the past. My goal for this line of research is to try to develop ways to study the histories of populations in terms of their size, ancestral relationships, and any migration that may have occurred between them.
I have also studied the mathematical properties of a common statistic used in population genetics to study population subdivision. I have found that this statistic has some interesting properties that must be kept in mind in order to properly interpret it. This statistic is very popular and is often mis- or over-interpreted, and if I can help people use it better then I will be a happy person.
Finally, I am currently working on studying anti-vaccination sentiment as what one might call a “cultural pathogen”, some sort of human behavioral trait that can be transmitted from person to person and that has a detrimental effect on some health-related trait (in this case, by hindering the acquisition of immunity towards a vaccine-preventable disease). I have found that transmissible anti-vaccine sentiment can change the dynamics of a disease in dramatic ways, making it much more difficult to get rid of the disease in a population. You can’t prevent disease transmission without properly understanding the relevant aspects of human behavior, and my work is intended to shed some light on the relationship between human behavior and disease.
Were there people (or one person) in particular to whom you would attribute your professional success?
I’d like to give a shout-out to my high school AP Biology teacher, Bruno Dworzak. I wasn’t really interested in biology until I took his class, and I acquired my love for evolution from him.
This would also be a good opportunity for me to thank my advisor, Noah Rosenberg, and the members of the Rosenberg lab. Working in the Rosenberg lab has been an excellent experience; it is a very friendly, supportive environment. Noah himself is an exceptional advisor who has really helped me guide my way through the often very muddy waters of the PhD process.
What advice would you offer to other grad students or postdocs who are considering pursuing a similar educational and career path as you?
Find something that interests you on a deep level so that you want to stick with it through the rougher times, when you aren’t making much ostensible progress. I have had several occasions where it took me months to figure something out, and I’m not even doing experiments!
What are your future plans? Where do you see yourself professionally in the next 5 or 10 years?
I plan to continue to use mathematics to study the process of evolution from a population genetics perspective, ideally leading my own research lab. I strongly believe in the importance of teaching and mentoring, so I plan to keep both as strong elements in my future plans.
Can you speak a bit to the role you see CEHG playing on Stanford campus?
CEHG’s Evolgenome seminars are a great way to bring together like-minded people who enjoy discussing interesting research in the fields of evolutionary and human genomics and I have learned a lot from the various talks given in this seminar series. The yearly symposium is also a notable event for bringing people from all over the place together to talk about their research. The fellowships offered by CEHG enable people like myself to conduct research that bridges the gap between fields (in my case, mathematics and evolutionary biology) in order to better understand nature and history.
Tell us what you do when you aren’t working on research and why. Do you have hobbies? Special talents? Other passions besides science?
My entire life outside of the lab is consumed by baseball: watching baseball, reading about baseball, competing in simulated baseball leagues with other people online, analyzing baseball statistics. Just all baseball. It’s a great way for me to take my mind off the never-ending turmoil of existence.