Final answer:
The cohesion species concept differs from the biological species concept by including natural selection in maintaining species boundaries despite gene flow, which isn't accounted for solely by reproductive isolation.
Step-by-step explanation:
The cohesion species concept includes elements not found in the biological species concept, such as the maintenance of species boundaries by natural selection, rather than solely by reproductive isolation. The cohesion concept recognizes that gene flow between species in hybrid zones does not necessarily dissolve species distinctions, as natural selection can maintain species integrity. This differs from the biological species concept, which defines species based on the ability to interbreed and produce fertile offspring.