Unit 1
What sampling strategy captures diversity along a landscape gradient?
transects
What is the term for structures that have no apparent function and appear to be residual parts from a past ancestor?
Vestigial structures
Intraspecific competition, interspecific predation, diseases, social behavior, etc. are all examples of what?
Density-dependent population regulation factors
Succession occurs via what three different mechanisms?
1. tolerance (no critical interactions
2. inhibition (some species arrive earlier and make it harder for species to invade later)
3. facilitation (some species arrive earlier and make it easier for species to invade later)
What must you consider when measuring biodiversity?
1. composition
2. richness
3. evenness
What must a clade include in a phylogenetic tree?
An ancestor and all of its descendants.
What type of growth occurs in populations with continuous reproduction and overlapping generations?
Exponential growth
Why does CO2 concentration fluctuate annually in the Northern Hemisphere?
Because plants perform more photosynthesis in the spring/summer (take in CO2 from atmosphere), but lose their leaves and respire in the winter (release CO2).
Habitat A: 11 loaches, 20 tetras, 6 catfish, 2 piranhas
Habitat B: 15 loaches, 13 tetras, 8 catfish, 3 piranhas, 6 angelfish
What are the alpha, beta, and gamma diversities?
Alpha: Habitat A = 4, Habitat B = 5
Beta: 1
Gamma: 5
What is the difference between a genotype and phenotype?
genotype: organism's allele combination
phenotype: organism's observed traits for a gene
Why do we expect larger islands to have more species?
1. higher habitat diversity
2. lower extinction rate
How might organisms respond to climate change? *four ways*
1. acclimate (short term)
2. adapt (long term)
3. move
4. go extinct
Give an example of why CO2 concentration has increased over time.
fossil fuel burning, forest destruction, biomass burning, etc.
What is the criteria for evolution by natural selection?
1. variation
2. heritability
3. differential survival / reproductive success
What can expedite the achievement of herd immunity?
Vaccination by increasing the proportion of recovered/immune individuals.
What are the external causes of climate? *three causes*
1. eccentricity (shape of orbit around the sun)
2. obliquity (planet's tilt)
3. precession (direction of tilt)
List one pathway in which nitrogen in manure can end up back in the atmosphere.
Two Possible Ways:
1. Manure -> Mineralization / Decomposition -> Nitrification -> Denitrification
2. Manure -> Mineralization / Decomposition -> Volatilization
What five assumptions does Hardy-Weinberg Equilibrium assume?
1. no mutation
2. no selection
3. no migration
4. random mating
5. infinite population size
Exponential growth assumes what is constant?
Assumes r (per capita rate of increase) is constant
What are today's major threats to biodiversity?
1. pollution
2. extinction
3. climate change
4. habitat loss and degradation
5. over-exploitation
6. introduced species