Invasive species can invade both large and small native populations and have a profound effect. Upon invasion, invasive species interbreed with native species to form sterile or more evolutionarily fit hybrids that can outcompete the native populations. Invasive species can cause extinctions of small populations on islands that are particularly vulnerable due to their smaller amounts of genetic diversity. In these populations, local adaptations can be disrupted by the introduction of new genes that may not be as suitable for the small island environments. For example, the "Cercocarpus traskiae" of the Catalina Island off the coast of California has faced near extinction with only a single population remaining due to the hybridization of its offspring with "Cercocarpus betuloides."