Gene sharing and the evolution of complex cells

Abstract

Two defining moments in biology were: 1) the demonstration that there are particles of inheritance, called genes, passed down from parent to offspring in a process that leads to biological variation and 2) variation is the raw material that drives evolution by natural selection. The coming together of these two theories, pioneered by Mendel and Darwin respectively, led to a great enlightenment in biology. One of the key ideas that arose from this synthesis was the proposition that by comparing genes across the diversity of life we will be able to calculate the tree of life and demonstrate how genetic variation underpinned the evolution of biological characteristics. This working model has been ‘dented’ on a number of fronts. A chief challenge to this idea is the demonstration that a large proportion of genetic information is not just passed from parent to offspring, but has instead at some point in the history of life been transferred horizontally between distantly related lineages. This process has turned out to be very important in the evolution of complex cells. I will discuss a few key examples of this phenomenon and our own work on horizontal gene transfer with reference to host-pathogen evolution.

Host: Professor Michael Brockhurst