Final answer:
The option not employed as a species concept is allopatry; species concepts include the ability to produce viable offspring, genetic similarity, and phenotypic similarity.
Step-by-step explanation:
The option that is not employed as a species concept is a. allopatry. The species concepts typically include the ability to produce viable offspring (c), genetic similarity (d), and phenotypic similarity (e). Allopatry pertains to the geographic separation of species and is not directly a species concept, but rather it is a condition that can lead to speciation through physical separation.
Individual genetic maps in a given species are typically genetically similar (a), but not genetically identical (b), reflecting natural genetic variation. Hybrids are produced when members of closely related species reproduce (c). The likelihood of allopatric speciation increases with longer distance between divided groups (b). The observable traits expressed by an organism are described as its phenotype (a). Hermaphroditism (d) is a form of reproduction that can be useful for an animal with little mobility that reproduces sexually. Asexual reproduction (a) produces identical offspring and is most successful in a stable environment.