EEB365H1 Chapter 1-10: Conservation Science Notes
28 Apr 2016
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Small populations are more vulnerable to become extinct by destructive nature (eg. floods, disease) and from genetic problems such as inbreeding and genetic uniformity. Iucn red list is a list of species at risk with relates extinction likelihood to population size. Challenge of small populations is that it creates a vortex of different risk factors, each of which must be overcome. The principle that if a population contains relatively few individuals, chance variations in the sex ratio of offspring or the survival and reproduction success of individuals can prevail over what is expected on average. Net effect = rate of population growth/decline will vary from year to year even if the environment remains constant. Demographic stochasticity can impinge on any aspect of birth, death, or mating and cause extinction. The probability of extinction declines exponentially as the population size increases, subdivision of the population magnifies demographic stochasticity.
