What is defined by the biological species concept?

The biological species concept defines a species primarily based on the ability of organisms to interbreed and produce fertile offspring. This concept emphasizes reproductive isolation, meaning that members of the same species are able to mate with one another and generate offspring that can also reproduce, ensuring the continuation of the species’ genetic lineage.

This definition highlights the importance of genetic compatibility and the role of reproduction in maintaining species boundaries. The focus is not just on physical similarities or habitat but on the potential for gene flow between organisms, which is crucial for the evolution and adaptation of species over time.

In contrast, definitions based on shared habitats, similar physical characteristics, or members of the same genus do not adequately account for the complexities of speciation or the potential for divergent evolution. Such characteristics may not necessarily indicate that organisms belong to the same species, as they could still be genetically distinct or unable to produce viable offspring together.