Case Study 3 Concepts
Terms in this set (20)
Succession (Primary, Secondary)
The process where species grow and are replaced by new species over time. Eventually, the ecosystem becomes a climax community, where the environment is stable and the process stops. No more room for more species. Primary succession is when the process occurs on a place where there is no soil. Pioneer speciec are the first to come to the area and develop soil. Secondary succession is when the proccess occurs where soil exists. It may be after the area is cleared by a natural disaster, etc.
Factors affecting diversity
Factors and events that can change the allele frequency in a population, aside from non random mating, migration, mutation and natural selection
When a small portion of a population breaks off and forms its own population. Whatever the allele frequency is for the founders, it will remain the same in future generations. Founding effects with a high frequency of disorders will be magnified, causing a high frequency of disorders in subsequent populations.
The drastic decrease of a population size due to an environmental effect. Whichever organisms survive will affect the allele frequency and will cause that different frequency to occur in subsequent generations. Population reflects the genetics of the survivors
The change in allele frequencies due to change (Law of independent assortment). The larger the population, the less effect chance will have on allele frequencies.Cna result in the elimination of a trait and decreased diversity
Migration, the movement of alleles between a population. Members of a different population with different allele frequencies will alter the frequencies in the initial populations. New genes in gene pool
Organisms that have beneficial genes are more likely to survive and have a greater diversity.
The maximum number of individuals from a species an environment can sustain based off resources, competition and predators. Can increase by decreased environmental resistance or decrease by a natural disaster and increased environmental resistance.
Logistic Population Growth, S- Curve
Populations that grow slowly and fluctuate near their carrying capacity (K). Most likely to be K-selected species, grow slowly and stabilize in the environment and most likely affected by density-dependent factors. Form an S Curve
Exponential Growth, J Curve
Populations that grow rapidly and overshoot carrying capacity. The population then crashes ina significant die back. Wild fluctuation in environment over time. Normally r selected organisms that are mostly affected by density independent factors
Period when population size is small so reproduction is slow. No rapid growth.
Exponential Phase or Log Phase
Time when population grows rapidly
Birth and Death equal, the population has reached carrying capacity.
Phase where population growth slows as it reaches carrying capacity
Population has overshot carrying capacity and die back significantly due to the environmental resistance.
A population that fluctuates because of births, deaths, immigration and emigration. Is represented as an S curve, as members can leave when the carrying capacity is reached and resources are maxed.
A population that only fluctuate due to births and deaths. Represents as a J curve, as the population will overshoot and the members cannot leave. Will die back.
Two organisms interacting and both benefit. Both populations will grow
Two organisms interacting where one benefits and one is indifferent. One population will grow and the other will remain the same
Two organisms interacting where one benefits and the other is harmed. One population increases and the other decreases.