Fortunately, Dr. Benjamin Jarrett from Bangor University has recently made great distance in figuring out how reproductive isolation works. This last factor is the most important in the origin of new species. His new work, published this week in Nature Ecology & Evolution, shows just how much those population differences can be influenced by environmental factors. These differences can enhance reproductive isolation and eventually promote species divergence.
Reproductive isolation is a classic indicator of how well two populations or species are prevented from interbreeding. This state of isolation can emerge automatically when a single population separates into two groups that are divided by geography. When these groups are maintained in distinct conditions, they often evolve to have specialized characteristics and habits. This impacts their mate choice and further develops their reproductive isolation.
Dr. Jarrett’s work highlights the idea that evolving in different environments speeds up the accumulation of reproductive isolation. He compiled data from 34 studies that analyzed reproductive isolation in laboratory settings, revealing compelling evidence that environmental differences play a significant role in this evolutionary process.
These results show that when two populations are exposed to different environmental conditions, they are less able to interbreed. This reduced chance of reproduction is important since it increases genetic isolation between the two populations. Put simply, populations that are adapting to different environments are more likely to diverge from each other genetically over time.
The study does underscore the principles of divergent selection. It indicates that this developmental process increases reproductive isolation beyond what is achieved by populations adapting to the same environment. As populations settle into their new environments, the likelihood of gene flow dwindles. This process serves to lock in their divergent evolutionary paths.
Dr. Jarrett’s research gives us fascinating glimpses into incipient speciation, as reproductive isolation mechanisms start to set in. The work demonstrates that populations are able to rapidly occupy the environments they find themselves in. As this occurs, the chance for genetic exchange diminishes, significantly contributing to the formation of new species in the wildlife realm.