alter the fact of the predominance of some life forms in oceans that are rare or nonexistent on land.
We must therefore conclude that accounting of species alone can be highly misleading as a yardstick of diversity. It may also mislead us genetically. The genetic diversity of both land and sea species can be striking, as, for example, the variation among the hamlet fishes, Hypoplectrus (Figure 4–4). But does a family of thousands of species contain more or less genetic uniqueness than a phylum comprising one to a dozen? Some marine phyla contain very few species, but their evolutionary history is long and their species are unique; the horseshoe crab, Limulus, is an example. In sum, a major challenge in examining diversity lies in our perceptions and interpretations of it, taxonomically and functionally.
A great diversity of life forms implies that there is an equally great diversity of food webs and trophic relationships, i.e., food supply and demand, and requirements