Open problems in evolutionary biology (experiments and/or theory)
Evolution of life over the last >3.5 billion years has shaped the life forms that we presently see on the planet. Developments in genome sequencing and molecular biology allow us to perform evolutionary experiments in lab, and see in real time, how environment shapes changes in a population. Understanding this relationship between the environment and the changes that take place in the DNA of an organism is the focus of our lab's research. We perform theory and also perform experiments (using yeast and bacteria) to answer questions of interest. Some of the open problems of interest are,
Speciation. How can a population of one species, inhabiting a particular geographical region, split into two species? Such an event is called speciation and is critical to understand biodiversity. (Experiments with yeast and/or Theory)
Bifunctional Proteins. In a landmark 1941 paper, Beadle and Tatum demonstrated that one gene encodes for an enzyme which catalyzes one reaction ("one gene, one enzyme" hypothesis). For this, they were awarded the Nobel Prize in 1958 (along with Lederberg). However, we now know that many proteins carry out more than one function in the cell. Often, making the protein better at one function comes at the cost of the other. This is an example of a trade-off and is an example of an "adaptive conflict". What are the mechanisms via which adaptive conflicts are resolved in an organism? (Experiments with yeast)
Genetics of Sexual Dimorphism. In most sexually reproducing species, the two sexes exhibit different physical characteristics (e.g., bright colors of the male birds vs. dull female colored birds; hoarseness in human male voices). These differences are referred to as "sexual dimorphism". These changes are maintained despite the fact that the only difference between male and female genomes is of one chromosome (e.g. males carry the Y chromosome (which is very small, with only a few genes on it) and females carry an additional copy of the X chromosome. How do the two sexes, while containing largely the same genes, maintain these different physical manifestations? In this project, we will use theory to understand the underlying genetics of sexual dimorphism. (Theory)
Evolution of Cooperation. Natural selection tells us that among the many species in an area, competition ensures that the fittest survives; while the others go extinct. However, we know of several examples where species in an environmental niche enter cooperative arrangements, resulting in stable existence of species. Starting from non-interacting populations, how do these cooperative interactions evolve over time? (Experiments with bacteria/yeast and/or Theory)
Background in biology is not needed. However, the interested student must have a strong interest and desire to learn evolutionary biology.