BIOLOGY 171 Lecture Notes - Lecture 18: Encase, Cestoda, Commensalism
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Lecture 18 notes: close interactions between species that have evolved over long periods of time are called symbioses, many of these interactions enhance the reproduction and population growth of both ecological partners. There mutually beneficial interactions are called mutualisms: many other interactions are one sided: one organism actually consumes another or competes with it for food or some other resource. Competition is an interaction in which the use of a mutually needed resource by one individual or group of individuals lowers the availability of the resource for another individual or group. e. ii. We saw that in many populations the tension between intrinsic rate of reproduction and environmental carrying capacity results in intraspecific competition competition within a species. The increase in competition between individuals of a species that accompanies increased population density is a main reason why population growth slows as the species" environment approaches its carrying capacity: competition promotes niche divergence f. i.
