BIOLOGY 171 Lecture Notes - Lecture 17: Herbivore, Parasitism, Arthropod
Document Summary
Chapter 32. 2. 1 & 32. 3. 1 inducible defense macroparasite microparasite obligate parasitism predation. Vocabulary (you should be able to define and use all of these terms correctly. ) commensalism community constitutive defense ectoparasite endoparasite facultative herbivory. Species interactions can be positive, negative, or neutral for the two interacting species. When we refer to a negative interaction, we mean an interaction between two species that reduces an organism"s fitness (the number fertile offspring produced) in a given environment. Sometimes ecologists measure surrogates of fitness, such as organismal growth rates or survival or population growth rates (because lifetime fitness is hard to measure for species such as pine trees, which can live for longer than a hundred years). A positive interaction would increase fitness, and a neutral one would not have a measureable effect on fitness. Sometimes both players in the interaction experience the same effect (negative/negative, positive/positive); other times, the effect on one player is different from the effect on the other (e. g. , positive/negative).
