BIO-8 Lecture Notes - Lecture 15: Robert Macarthur, Intraspecific Competition, Interspecific Competition
Document Summary
There must be niche differences for competing species to coexist stably. Each species must have its own niche space. Species specialized on different part of canopy. Other evolve to get niche differences and coexist. One form of trait reduces the extent of competition more than the other form of the trait. Let"s look at the issue as one of niche breadth. Thus, we expect some but not complete niche overlap. An example of evolutionary tradeoffs r-, k-, and alpha-selection. Some species usually exist near k (resource space limited so species can"t expand beyond k) If a heritable phenotype arises, it"s bearers have an advantage in the context of within species competition. That phenotype would spread and have an advantage. Over time all individuals be more efficient and resemble that phenotype. Increase in k, due to increase in efficiency. Evolutionary divergence in areas of sympatry (co-occurrence)
