Download Research Abstract: The evolution of life has resulted

Research Abstract: The evolution of life has resulted in the
cooperative aggregation of cohesive units that prosper together. These
units may be the same, as with the evolution of multicellularity, or
they may be different, as with the evolution of the eukaryote cell. For
such cooperation to evolve, conflicts at lower levels must be
controlled. We study the evolution of cooperation and the control of
conflict in a microbial eukaryote, the social amoeba Dictyostelium
discoideum. It is uniquely suitable for this work because transitions
that are fixed in most organisms are still flexible. This amoeba preys
on bacteria but, when starved, aggregates into a multicellular body
that moves towards light, and then differentiates into 20% dead stalk
cells that support 80% living spore cells. When the multicellular stage
is chimeric, the opportunity for one clone to cheat the other arises. We
identify genes involved in this process, look at their rates of evolution
using 20 resequenced clones and a handful of sequenced closely
related species. We use experimental evolution to look at the
robustness of the social process and the importance of high genetic
relatedness within fruiting bodies in maintaining the altruistic caste.
We explore kin recognition and its genetic basis. We study the
evolution of development by constructing pseudo-organisms with
artificial life cycles where we manipulate things like single-cell
bottlenecks. We have found that some clones carry bacteria with them
in a farming and defensive mutualism, and use this to experimentally
study mutualism. In sum, our group studies what's crucial to
organismality.