Biodiversity & Evolution • Populations evolve by becoming genetically different • Differentiation due to mutations • Natural selection
Ecological Niches • An ecological niche is a species’ way of life in an ecosystem – everything that affects its survival and reproduction. • Includes: • Population members adaptations • Its range of tolerance for abiotic conditions • Its interactions with other components of the ecosystem • Its role in energy flow and matter recycling
Niche • Fundamental Niche – Full potential range of conditions and resources the species could potentially use. • Realized Niche – Is the part of the potential niche that is utilized by and allows the species to survive and avoid competition with other species for the same resources.
Generalist Species • Broad ecological roles • Broad range • Eat a variety of foods • Tolerate wide range of abiotic factors • Survivability in a changing environment good
Specialist Species • Live in very specific environments (endemic) • May have very specific foods • Specialists normally have few competitiors in constant, unchanging environment • More prone to extinction in changing environmental conditions
Extinction • Endemic species are more susceptible to extinction. • 4 Key Variables • Geographical Distribution • Speciation to a given habitat or food • Genetic variation of gene pool • Reproductive Rate
Panda Narrow distribution Small population Low genetic variation Large size Small # of offspring Limited migration Mouse Wide distribution Large population High genetic variation Small size Large # of offspring High migration Which Species Will Survive in a Rapidly Changing Environment?