EHSC 3060 Lecture Notes - Lecture 5: Natural Disaster, Symbiogenesis, Commensalism
Document Summary
Natural selection: the process whereby organisms better adapted to their environment tend to survive and produce more offspring. Also occurs because of selective pressure (predation, natural disaster, sexual selection): two types of adaptation. Acclimation: an organism getting used to an environment. Epigenetic: change made to dna by the addition of methyl groups: evolution: Occurs over a long period of time based on many different factors: speciation: finches having different sizes and shapes of beaks to compete for different types of food, types of selection: Directional selection: some trait(s) become more preferable than others for a speci c generation, so the population (all together) moves toward that particular trait (such as speed being a necessity to escape predators). Disruptive selection: traits among a species split up and slowly become separate species (such as with the nches and the different shapes and sizes of beaks).