What does the biological species concept proposed by Ernst Mayr emphasizes?

The biological species concept, proposed by Ernst Mayr, emphasizes the idea that a species is defined as a group of organisms that can interbreed and produce viable, fertile offspring in natural conditions. This concept highlights reproductive isolation, meaning that members of different species do not typically mate or produce fertile offspring. It focuses on the role of genetic exchange within a species while distinguishing it from other species through barriers to reproduction. Overall, it underscores the significance of reproductive compatibility in defining species boundaries.