LIFESCI 1 Lecture Notes - Lecture 25: Overdispersion, Overfishing, Exponential Growth
Document Summary
Introduction: population = defined by 3 key features: 1) size = number of live individuals of all ages. Range = how widely a population is spread out. Determines how much variation in climate a population can tolerate. Also how many other species the population encounters. Density = size divided by range = average across a range of species. Can be misleading if organisms occur unevenly within a range. Randomly distributed: a new individual has equal chances of occupying any position within the range and location of one individual = no influence on neighbors. Patchy distribution: chances of individual"s survival are enhanced by the presence of others, populations may be clumped when individuals cluster together so survival can increase. Over-dispersion = distributed more uniformly than would be predicted by chance. If individuals all depend on the same set of resources = won"t settle together: or if predators target a single species, long ranger survives best.
