Rowan D.H. Barrett
Evolutionary biology
Harvard University

Rowan D.H. Barrett

Scientists could enhance their ability to predict various species’ risk of extinction, thanks to research on the genetic basis of adaptation.

Rowan Barrett, winner of NSERC’s 2010 Howard Alper Postdoctoral Prize, is combining field studies with genomics to uncover the genes that make certain members of species better able to adapt to climate change or other factors in their environment.

A species’ population is composed of individuals with different genetic programs, known as genotypes. When ecological conditions change, certain genotypes may be more effective than others in adapting to the new environment, and will be favoured by natural selection. That genetic advantage means individuals with those genotypes are more likely to survive and breed successfully. Over several generations, this changes the genetic composition of the population.

Dr. Barrett’s research tracks this evolutionary path by moving populations into new environments that will require adaptation and then observing changes in the frequency of different genotypes. This makes it possible to measure natural selection occurring at the genetic level.

For example, the marine stickleback fish adapted from the ocean to fresh water lakes and streams thousands of years ago. Dr. Barrett re-created this process in a controlled setting during his doctoral research and discovered how the fish were able to adapt to different temperatures, salinity and predators in this new environment. Building on this work, he will study the impact of natural selection in deer mice. The mice will be placed in habitats where their coat colour does not match the colour of the soil, providing less camouflage from predators. Dr. Barrett is developing new genomic techniques to study how interactions between adaptive genes result in the evolution of better camouflage.

Many central questions related to genetic basis of adaptation remain unanswered. Dr. Barrett’s work will test the predictions of current evolutionary theory to provide valuable insights into how organisms adapt to their environments, which will greatly aid in maintaining biodiversity.