Lecture 15 Flashcards
Evolution
Changes that take place in a species over time.
Genes and environmental conditions determine survival and reproduction.
Mutation is random part of evolution.
Natural selection
Some individuals are better adapted to an environment, so more likely to pass genes to the next generation. Driving force of evolution. Not random.
Micro evolution
Change over time within a species.
Macro evolution
New species evolve (speciation), often after separation into different environments.
Charles Darwin and Alfred Russel Wallace
Each came up with natural selection theory separately.
Charles Darwin
Sailed from England and found finches on Galapagos Islands.
Artificial selection.
Species range
Area where a species is found.
Range determined by where species can get to and if it can survive there.
Humans = wide range (global), specific plant species = limited range.
Dispersal
Ability to move to new area.
Barriers are geographic obstacles to dispersal.
Plants; seeds blown by wind or just drop, float in water.
Animals; walk, fly, swim.
Adaption
Species evolve by becoming better adapted to surroundings.
Biotic adaption
Adapting to other species/living things.
Biotic factors
Interaction with other species, competition, and predation.
Abiotic adaption
Adapting to non-living environment, like temperature, water, topography. Migrating.
Limiting factor
If one factor determines the species range.
Ecology
Study of organisms and how they interact with one another and with the physical environment.
Ecosystem
Organisms and physical environment of a particular area. (Tropical rainforest, desert, grassland, pond).
Energy
Begins as insolation. Producers (plants) covert sunlight into sugars (photosynthesis). Primary consumers eat plants. Secondary consumers eat primary consumers. Secondary consumers get eaten by tertiary consumers. Decomposers eat dead at all levels.
10% of energy goes to next level, 90% used for respiration.
Biogeochemical cycles
Carbon cycles (air to plants, plants to animals, plants/animals to decomposers, plants/animals/decomposers to air by respiration, some remains in soil). Nitrogen cycle (N in atmosphere not useful for life. N fixing bacteria found on roots of certain plants, convert N to useable forms in soils. Plants get N from soil. Animals eat plants. Etc. Released to atmosphere in decomposition).
Biodiversity
Number of species in an area.
Introduced species
Intentional and unintentional.
