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This article explores how populations evolve and adapt in response to changing environmental conditions. It delves into ecological niches, fundamental versus realized niches, and the characteristics of generalist and specialist species. The discussion also encompasses the factors influencing extinction risk, such as geographical distribution, genetic variation, and reproductive rate. By comparing the traits of pandas and mice, it poses the question of which species are more likely to survive in rapidly changing environments.
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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?