Question

Consider two sister clades of marine invertebrates, where each clade consists of multiple species. The species Clade 1 all have planktonic larva (the larva stay in the water column and can disperse vast distances in the ocean). In contrast, Clade 2 species all produce larva that settle quickly on the ocean floor, and never disperse far from their parents. Briefly describe how larval lifestyle satisfies the third requirement of Species Selection (that it impacts the survival or extinction of the clade).

Answer 1

The species of clade 1 remain in the ocean column and collects food from the ocean column and they also move from one place to another though water current and thus consume food from different locations of ocean. Whereas species of clade 2 settles at the bottom and they mainly feed on the bottom located foods and thus the two clade separates their niche. The niche separation always leads to coexistion of two clade. As the species of these two sister clade collect food from different areas of ocean and live in different layer of the ocean, the competition between these two clade will NOT be severe and this will help them to coexist and chance of extinction due to competition for overlapping niche will not be there. So they will coexist.