Thesis Defense at CES on 24 July 2015 at 4:00 pm titled "Molecular ecology of the primitively eusocial wasp *Ropalidia marginata*: relatedness, queen succession and population genetics" by Saikat Chakraborty from CES, IISc
The evolution of extreme form of altruism in the form of forsaking reproduction in order to help others to reproduce is arguably one of the most interesting paradoxes in biology. One of the theoretical frameworks that allows one to understand the evolution and maintenance of such behaviour is W D Hamilton's kin selection theory. *Ropalidia marginata*, a species of wasp in which generally only a single female lays all the eggs at a time, though most of the females are capable of developing their ovaries and laying eggs, is an excellent system to study the implications of this theory. One of the parameters in this framework is genetic relatedness. In my work I have estimated this parameter in the initial colony founding stage as well as in mature colonies. I have also constructed several models based on this framework in order to predict the next queen, and tested them. In addition I have studied the genetic structure of *R. marginata* populations. I found nestmate relatedness to be lower than the expected 0.75, with newly founded colonies having even lower average relatedness than mature ones. The queen's successor could not be predicted form any of the models. Regarding its population, *R. marginata* had quite high level of structuring and absence of any inbreeding. Moreover, structuring was higher at the level of the colonies.