Define ecology. Identify the two features of organisms studied by ecologists. Ecology is the scientific study of the interactions between organisms and the environment, which in turn determine both the distribution of organisms and their abundance. Ecologists study how interactions between organisms and the environment affect phenomena such as the number of species living in a particular area, cycling of nutrients in a habitat, and the growth of populations.
Describe the relationship between ecology and evolutionary biology. Darwin’s extensive observations (ecological studies) of the distribution of organisms and their adaptations to specific environments led him to propose that environmental factors interacting with variation within populations could cause evolutionary change. We now know that events that occur in the framework of ecological time (minutes, months, years) translate into effects over the longer scale of evolutionary time (decades, centuries, millenia, longer than that). Example- Hawks eating mice reduce population size (ecological effect) and alter the gene pool (evolutionary effect). Long term effects may be selection for mice with fur coloration that camouflages the animals.
Distinguish between abiotic and biotic components of the environment. Abiotic: Nonliving components; chemical and physical features such as temp, light, water, nutrients. Biotic: Living components; the biota is all organisms.
Example- Abiotic factors may have indirect effect on organisms via biotic factors. Higher precipitation may impact kangaroo distribution in Australia (lower the better), or climate may influence through biotic factors such as pathogens, parasites, competitors, predators, food availability (increased biota as result of rain).
Distinguish among organismal ecology, population ecology, community ecology, ecosystem ecology, and landscape ecology. Organismal Ecology: Concerns how an organism’s structure, physiology, and (for animals) behavior meet the challenges posed by the environment. Population Ecology: Concentrates on factors that affect how many inviduals of a particular species live in an area. Community Ecology: Deals with array of interacting species in a community. This area focuses on how interactions such as predation, competition, and disease, as well as abiotic factors such as disturbance, affect community structure and organization. Ecosystem Ecology: Emphasis on energy flow & chemical cycling among the various biotic and abiotic components. Landscape Ecology: Focuses on the factors controlling exchanges of energy, materials, and organisms among the ecosystem patches making up a landscape or seascape.
Clarify the difference between ecology and environmentalism.
Ecology provides an understanding of the relationships between orgasnisms and the environment, while environmentalism is the act of advocating for the protection or preservation of the natural environment. Ecologists can provide the general public and policy makers with information on/for decisions that can affect the environment; many actions are based off the precautionary principle- basically “an ounce of prevention is worth a pound of cure”.
Interactions Between Organisms and the Environment Affect the Distribution of Species 6.
Biogeography: Study of the past and present distribution of individual species, in the context of evolutionary theory.
Describe the questions that might be asked in a study addressing the limits of the geographic distribution of a particular species.
Dispersal limits distribution? Species may not be widely distributed due to barriers (leading to geographic isolation) or may have been able to overcome them and have been dispersed long-distance. There is also the issue of insufficient time, as some species may relatively suddenly expand their range and rapidly take hold. (Potential and actual range differ.)
Behavior limits distribution? Adaptation is...
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