Biologists watch speciation in a laboratory flask November 29, 2016 Please Register or Log in to view the hidden image! Molecular models of the two receptors the virus evolved to specialize on. Credit: Justin Meyer, UC San Diego Biologists have discovered that the evolution of a new species can occur rapidly enough for them to observe the process in a simple laboratory flask. In a month-long experiment using a virus harmless to humans, biologists working at the University of California San Diego and at Michigan State University documented the evolution of a virus into two incipient species—a process known as speciation that Charles Darwin proposed to explain the branching in the tree of life, where one species splits into two distinct species during evolution. "Many theories have been proposed to explain speciation, and they have been tested through analyzing the characteristics of fossils, genomes, and natural populations of plants and animals," said Justin Meyer, an assistant professor of biology at UC San Diego and the first author of a study that will be published in the December 9 issue of Science. "However, speciation has been notoriously difficult to thoroughly investigate because it happens too slowly to directly observe. Without direct evidence for speciation, some people have doubted the importance of evolution and Darwin's theory of natural selection." Read more at: http://phys.org/news/2016-11-biologists-speciation-laboratory-flask.html#jCp
http://science.sciencemag.org/content/early/2016/11/21/science.aai8446 Ecological speciation of bacteriophage lambda in allopatry and sympatry: Abstract Understanding the conditions that allow speciation to occur is difficult because most research has focused on either long-lived organisms or asexual microorganisms. We propagated bacteriophage λ, a virus with rapid generations and frequent recombination, on two Escherichia coli host genotypes that expressed either the LamB or OmpF receptor. When supplied with either single host (allopatry), λ improved its binding to the available receptor while losing its ability to use the alternative. When evolving on both hosts together (sympatry), the viruses split into two lineages with divergent receptor preferences. Although the level of divergence varied among replicates, some lineages evolved reproductive isolation via genetic incompatibilities. This outcome indicates that, under suitable conditions, allopatric and sympatric speciation can occur with similar ease.
