Population regulation and speciation in the oceans

The recruitment problem is a component of the broader question of the regulation of animal populations. For marine fish species with complex life histories, the specific patterns in spawning location, and the associated numbers of populations, are interpreted as being a function of the requirement for coherence at the early life-history stages in the face of the diffusive and advective characteristics of the oceans. Such observations generate a population-regulation hypothesis (member/vagrant) to account for 4 population characteristics. The hypothesis accounts for why there are a specific number of populations for different marine species, and provides an ecological basis for the orgin of reproductive isolation between species.