Exam #1 Flashcards
Environment
The surroundings or conditions in which a person, animal and/or plant needs to survive
Ecology
Focuses on the abundance and distribution of organisms in relation to their environment, and to each other
Ecosystem
The combination of a community of organisms and its physical and chemical environment, functioning as an integrated ecological unit
Negative feedback
Reverses the direction of change (introduction of wolves in an environment)
Positive feedback
Accelerates the direction of change (more rain, more grass, more deer)
Scientific method
Tragedy of the commons
Decline and destruction of the natural resources shared in a community (nothing to prevent an individual from exploiting a resource)
Triple bottom line
The ideal image for a company to have supports planet, people, and profit (goal is sustainability)
Preservationist
Protecting and preserving public land in its pristine state (even if it helps, don’t touch it)
Conservationist
Using the environment, but conserving biological life and ecosystems (ok to use if it helps humans, but don’t exploit it)
Anthropocentric ethics
Only humans have intrinsic value (everything else has instrumental value bc it helps humans)
Biocentric ethics
Other living things have equal value to humans (they don’t need to benefit us to have value)
Ecocentric ethics
Communities of organisms and ecosystems have intrinsic value
Environmental policy
Rules that guide decisions and actions that influence environmental conditions or processes (plan)
Incentives
Encourage actions by offering something in return (tax credits for buying solar panels)
Environmental law
The concern of the conservation, usage, and treatment of the natural world in government law (action)
Cell
Basic unit of structure and function of all life (energy flows through cells)
Prokaryotes
Single-celled organisms (bacteria, archaea) without a nucleus
Eukaryotes
Humans and animals that do have a membrane-enclosed nucleus containing DNA
Genotype
Genetic makeup of an organism
Phenotype
How an organism looks, combination of genotype and environment
Immigration
Moving in
Emigration
Moving out
Pull factors for immigration
Freedom, education, employment
Push factors for emigration
War, famine, oppression, persecution
Directional selection
Survival of individuals at one extreme end of range of variation (ex: larger seeds, larger bird beaks)
Stabilizing selection
Selection favors traits falling in middle or range of variation (ex: human birth weight)
Founder effect
Reduced genetic diversity resulting from the immigration of a small subset of a population (when populations are isolated over time, they follow different evolutionary pathways and become separate species)
Disruptive selection
Traits that fall within extreme ends of range of variation survive (ex: contrasting environments, only small and large survive)
Mutation
Random mistakes in the copying of genes or when cells are exposed to chemicals or environmental hazards that can be passed from parent to offspring (ex: Down syndrome)
Population growth rate
% of change over time (ex: 100 individs. year 1, 110 individs. year 2 = 10% year)
Exponential population growth
Number of new individuals in a generation is a multiple of number present in previous generation
Survivorship curves
Plot of percentage of individuals of a pop. that survive to each age
Carrying capacity
The rate at which resources are supplied limits the pop. growth
Evolution
The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth
Survival of the fittest
Organisms with genes better suited to the environment are selected for survival and pass them to the next generation
Natural selection
- Variation in the trait within the population
- Trait determined by genetics and inheritable
- Individuals with certain variants of the trait have higher fitness
- Competition for survival and reproduction within a population
Taxonomy
The classification of organisms through description, identification, and naming
Demographers
Study the characteristics and consequences of human population growth
Net migration rate
Difference between immigration and emigration rates
Ecological footprint
The amount of land needed to supply the demand for ecological goods and services
Biocapacity
Measure of the area and quality of land available to supply a population with resources
Pre-agricultural period of human population growth
Ambiguous number of humans who existed, human growth was low, hunter/gatherer
Agricultural period of human population growth
Population growth expanded because people were sedentary, domesticated plants and animals, and stored food
Expanded carrying capacity of humans
Humans are special because we can expand the limits of carrying capacity (pop. growth is somewhat unlimited)
What impacts birth rates?
Wealth and incentives
What impacts death rate?
Amount of land, nutrients, access to medicine
