How is a species defined?

A species is defined as a group capable of interbreeding and producing fertile offspring. This definition highlights the biological concept of species based on reproductive isolation and genetic continuity. Members of the same species share similar characteristics and can mate with one another to produce viable offspring, which is essential for maintaining the species over time.

This definition underscores the importance of both genetic compatibility and the ability to reproduce successfully. It distinguishes members of one species from those of another, often conflicting species, which may compete for the same resources or habitat but do not produce fertile offspring when they do interbreed.

In contrast, the other options present definitions that do not adequately capture the essence of what constitutes a species. A genetically identical group suggests clonal organisms, which does not reflect sexual reproduction. A community of various organisms implies an assemblage of different species coexisting in a particular area, which is more about ecological relationships than species definition. Lastly, a collection of individuals from different ecosystems fails to focus on genetic and reproductive criteria, which are central to defining a species.