In this project, the susceptibility of small populations to extinction will be studied. Some organisms can only reproduce asexually (i.e., clonally), and theory holds that if their populations dwindle to small numbers, then they are at risk for the accumulation of harmful mutations and extinction. However, it has been proposed that organisms that can shuffle, or recombine, their DNA during reproduction will not be as at-risk when their numbers are low. In the laboratory, the relationships among the intensity of recombination, the population size, and the probability of extinction will be modeled using populations of ribonucleic acid (RNA) in test-tube environments. RNA is chemically similar to DNA but can have life-like catalytic activity, as do whole organisms, and is thus perfectly suited to laboratory experiments aimed at testing how recombination slows the loss of this activity in spite of harmful mutations.
This project will be carried out at Portland State University in Oregon and will involve the training of both undergraduate and graduate students and high-school science teachers. The results will bear directly on strategies to manage small populations, be they endangered species in the wild or in zoos, populations of cells in the body or in the lab, such as cultured cells grown to study cancer, or populations of viruses during
