Population ecology Flashcards
Populations
A group of individuals from the same species inhabiting a specific place at a specific time
Species
A group of populations whose individuals have the potential to interbreed and produce fertile offsrping
Genotype
A genetic makeup of an organism (genetics)
Phenotype
The physical and physiological traits of an organisms (how genotypes show up)
Phenotype plasticity
Variation among individuals in form and function as a result of environmental. Incluences
Heritability
Proportion of total phenotype variation in a. Trait (for example body size) that is die to genetic variance
Hardy Weinberg assumptions
1- mating is random
2-populations of infinite size, no genetic drift either
2-no migration
4-no mutations
5-no selection, all genotypes have the same fitness
evolution
Changes in gene frequencies in populations over time
Agents of evolution
1-genetic drift
2-gene flow
3mutations
4-natural selection
genetic drift
Stochastic, random shifts in allele frequencies (more likely in small populations)
mutations
(Rare) changes in organisms DNA
gene flow
Loss of gain of alleles via emigrations or immmigration, tends to reduce differences between populations
Natural selection
Differential survival and reproductions among phenotypes
stabilizing selection
-acts against extreme phenotypes and this favors the average
-reducers ariatio, does not change mean
directional selection
-favors an extreme phenotype over others
-usually a result of anviromental change or migration
disruptive selection
-favors 2 or more extreme phenotypes
distributions
Size, shape and location occupide
density
Number of individuals per unit areaa
abundance
Number of individuals in a specific area
niche
N-dimensional hypervolume, where n is the number of environmental factors important to the survival and reproctiona of a species
fundamental niche
Physical condition sunder which a species might live in the absence of interactions with other species (Where something “CAN” survive)
** realized niche**
Restricted nick limited by biotic interactions such as competition and predation(where something DOES live, within the fundamental niche)
cohort
Group born during the same time period