A group of USC molecular biologists, mathematicians and computer scientists will undertake an ambitious study of the genetic basis of evolutionary adaptation, thanks to a three-year, $2 million grant from the W. M. Keck Foundation.
The work will seek to fill in several critical missing links, including the genetic key to the evolution of Homo sapiens.
In a suite of four projects, the researchers will examine gene expression, mutation patterns and heredity in bacteria, plants, oysters and humans. Their goal is to home in on the genetic fundamentals that underlie how complex traits evolve – whether it is a microbe’s resistance to a toxin, a plant’s tolerance for drought or the growth patterns of a primate’s forebrain.
Nineteenth-century British naturalist Charles Darwin held that small, heritable variations tend naturally to accumulate across generations to create fitter creatures and eventually new species. Ever since, biologists have toiled to understand the specific underlying processes of such adaptation.
Yet the complexities of gene expression and development have stymied most attempts to get a good picture of how genes get shuffled and changed to produce adaptation. Only with the very recent confluence of advances in computer science, molecular genetics and techniques for statistical analysis have projects like this one become feasible.
Indeed, the USC project is unique for its interdisciplinary breadth and ambition, according to assistant professor of molecular biology Magnus Nordborg, one of its main researchers.
Project 1 will focus on evolution in bacteria. Through a combination of targeted gene-deletion, “DNA chips” to track gene activity and sophisticated new methods to analyze the data, the researchers hope to identify a core set of genes that are necessary to the cells’ ability to evolve and self-repair.
The other three projects will focus on multicellular organisms. Project 2 will use a powerful gene-mapping technique called linkage-disequilibrium to seek the genes ultimately responsible for adaptation in plants.
Project 3 will study oysters to try to explain the long-known and perplexing phenomenon of “hybrid vigor” – the fact that the offspring of individuals from two inbred populations are frequently more fit than either of their parents.
And Project 4 sets its sights on identifying the crucial set of genes that turned Homo erectus into modern humans over the last million years.