Advantages in defining species by shared mate recognition systems rather than by interbreeding

• Practical advantage

Mate recognition systems can often be observed in specimens (for instance with these cleaner fish opposite) whereas interbreeding is more difficult to observe and is usually inferred indirectly.

• Theoretical advantage

The recognition concept may represent more accurately what happens when a new species originates. It has been argued that the crucial event for the origin of a new species is the evolution of a new mate recognition system.

Preference for the recognition concept stems from the relative importance of mate recognition systems and isolating mechanisms in speciation: if the former is causal and the latter more of a consequence then the recognition species concept better represents the causal process of speciation.