Below is my re-write of the case study argument that we worked on last week. It comes from Hutchinson 1959 and is titled. "Interrelations of food chains."
Among ecologists, the question of why there are so many species of animals can be answered by looking at the way food webs function. Food webs consist of many levels and often a level will contain more than one species. If one of those species becomes scarce, a predator will have an alternate food source and, therefore, the extinction of any of the species will be prevented. As a result, a community with greater species diversity will be more stable and will also outlast a less diversified community.
Regardless of stability, community food web structure will evolve. A more efficient species will replace one which is less efficient. If a new species is introduced it may completely replace a pre-existing species or it may share that level of the food web. A new species may also fill in an area of the food web that was not previously occupied. These possibilities of change within a community can work to increase stability. However, there seems to be a point at which further diversification levels off and the opportunities for new species to invade become rarer. The unanswered question that remains is what causes this leveling off and why are there not more different kinds of animals?
No comments:
Post a Comment