Population Distribution and Abudance
A group of individuals of the same
species that live within a particular area
and interact with one another.
What is a population?
TRUE or FALSE: Population fluctuations increase the chance of a population going extinct.
TRUE
The maximum number of individuals supported in a
habitat.
A +/- relationship in which one organism benefits by feeding on, and directly harming, another.
What is exploitation?
Predation, herbivory, parasitism, and disease.
Cell organelles, chloroplasts, mitochondria, evolved from single-celled organisms (bacteria) that lived in a close mutualism inside cells of other organisms.
What is endosymbiotic theory?
Events that kill or damage some individuals, creating opportunities for other individuals to grow and reproduce.
What is a disturbance?
Individuals have difficulty finding mates, or
flowers pollinated, at low population
densities.
What are allee effects?
The 3 trends seen in population growth.
1. Exponential growth
2. Self-limitation
3. Trophic oscillations
Animals will maximize the amount of energy gained per unit time, energy, and risk involved in finding food; assumes that evolution acts on the behavior of animals to maximize their energy gain.
What is optimal foraging theory?
The definitions of the two theories of coevolution.
Arms race = coevolving species have to constantly ‘improve’ to meet each new adaptation with a ‘better’ adaptation of their own, resulting in an escalation of offensive and defensive traits over time
Red queen hypothesis = the arms race results in no evolutionary ‘winner’ or ‘loser’ – species constantly adapt (‘run’) simply to keep up and avoid extinction
The 4 methods used to estimate population size.
1. Area-based counts
2. Point sampling
3. Mark–recapture
4. Line transects
N(t+1) = N(t) + B – D + I – E
N(t) = Population size at time t
B = Number of births
D = Number of deaths
I = Number of immigrants
E = Number of emigrants
The 2 types of breeders, which has a significant effect on population growth.
What are discrete- and continuous- breeding organisms?
The definitions of the 2 main types of parasitism, and an example of each.
Ectoparasites/macroparasites = parasites that live on the outer body surface of the host (ex: lice, ticks, bed bugs, etc.)
Endoparasites/microparasites = parasites that live inside their hosts, within cells or tissues or in the alimentary canal (ex: tapeworm, coccidia, flukes, etc.)
The effects of facilitation.
– Resource enhancement
– Recruitment enhancement
– Predation refuge
– Habitat amelioration
Lineages that occupy 60–90% of the world; includes amphibians, reptiles, mammals, and birds. Give an example.
What is a cosmopolitan distribution?
Examples- Bufo marinus (marine toad), Falco peregrinus (peregrine falcon), Order Testudine (sea turtle)
The 4 main factors that can drive populations to extinction.
- Predictable (deterministic) factors
- Fluctuations in population growth rate
- Fluctuations in population size
- Chance events
An explanation for density dependence in sandflies.
Egg-laying depends on feeding success.
The definitions of the 2 mechanisms of interspecific competition, with an example of each.
Interference = prevent access to resources (ex: seabirds, skuas, jaegers, bald eagles, hyenas, Chinese shrub wormwood, etc.)
Exploitative = organism depletes resources used by competitor (ex: plant galls)
The 3 types of mutualism, with an example of each.
1. Protection mutualism (ex: ants protect plants and herbivores for sugar)
2. Nutritional mutualism (ex: termites use protists to eat wood)
3. Dispersal mutualism (ex: ant-dispersed seeds possess elaiosomes)
These are examples of random, aggregated, and regular patterns of dispersion.
Random- penguins, many deciduous trees
Aggregated- flower patches, schools of fish, clonal plants, black-chinned hummingbirds
Regular- desert plants, Seychelles warblers
The steps to create a stage-structured population model.
1. Divide population into stages
2. Document survival and reproduction in each stage
3. Calculate probability of changing stage from one year to another
This Scottish species showed exponential growth over the course of 100 years.
Fulmaris glacialis (fulmar)
The effect of introducing the Nile perch in Lake Victoria.
Extermination of many cichlid fish species.
An explanation of Ant-Acacia mutualism.
Facultative mutualism between ants and Acacia plant.
Ant benefits: Food (N rich Beltian bodies), nest sites (hollow thorns)
Acacia benefits: Herbivore defense, Nitrogen