Experimental tests of the role genetic architecture, resource competition, and gene flow play during speciation

University Of California-San Diego, La Jolla CA

Investigators

Abstract

One of the first lessons students receive in biology class is that life is organized into species; clusters of organisms that look alike and share similar DNA. The pattern of species is so ubiquitous that the question of why this pattern occurs is often overlooked. Why has life not evolved into a single superorganism rather an array of species, or why has it evolved into discrete clusters rather than a continuum? Researchers who study the process called speciation aim to answer these fundamental questions. This project is one of the first of its kind to extend the research of speciation to viruses. Until recently, it was thought that viral diversity was arrayed along a continuum and did not coalesce into distinct species. New information on viral genetics has revealed that viruses do indeed form into distinct clusters. The researchers will use laboratory experiments and state of the art biotechnologies to determine how different biological variables affect viral speciation. This research will add to a general understanding of speciation, as well as to improve our understanding of the drivers of viral evolution. The researchers will design teaching modules for undergraduate students to learn about virus classification and speciation, while also contributing to virology research. In 2016, the researchers published a landmark paper in the journal Science where they reported observing a virus called bacteriophage lambda evolve into two new species. This was a unique observation because speciation was thought to take too long to observe during the course of a laboratory experiment and because at the time, it was debatable whether or not viruses formed into species. The research group is building on this previous result by determining how three biological variables – genetic architecture, resource competition, and gene flow – affect lambda’s speciation. To accomplish this, the researchers will employ synthetic biology technologies to measure the fitness landscape of lambda, computer programs to simulate and predict lambda evolution, and evolution experiments to test the predictions. In addition, an education module will be created to teach students in a course called Phage Hunters about viral speciation and species concepts. Phage Hunters is taught at universities worldwide and provides training through authentic research experiences. One of the goals of the module will be to have students perform research by discovering new viral species through bioinformatic analyses. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.