8-Genetics and the Evolution of phenotypes

Phenotype

The expressed physical characters of an organism.

Genotype

The genetic make-up of an individual.

Melanic Form

A color variant of species, particularly studied in the peppered moth due to its mutation and selection.

Polygenic Traits

Traits controlled by multiple genes, often resulting in continuous variation.

Natural Selection

The process through which populations adapt to their environment by favoring the survival and reproduction of individuals with advantageous traits.

Linkage Equilibrium

A condition where two loci and their alleles are independent and not linked on chromosomes.

Linkage Disequilibrium

The non-random association of alleles on a chromosome, where linked genes are inherited together.

Epistasis

An interaction between two or more alleles in a non-additive manner, affecting the expression of one allele based on the presence of another.

Heritability

The proportion of variation in a trait that can be attributed to genetic variation among individuals.

Continuous Variation

A type of trait variation where individuals display a range of phenotypes, such as height.

Disruptive Selection

A type of selection that favors extreme variations of traits over intermediate variants.

Genetic Variance

Differences in genetic code that contribute to the variation in phenotypes.

Environmental Variance

Variation in a trait that is influenced by environmental factors or development.

Additive Genetic Variance

The portion of genetic variance that contributes to the phenotype in a cumulative manner.

Fecundity

The reproductive success and ability of an organism to produce offspring.

Selection Differential

The difference between the average phenotype of selected parents and the average phenotype of the entire population.

Stabilizing Selection

A type of selection that favors average traits, reducing variation in a population.

Correlated Selection

The phenomenon where selection on one trait affects the evolution of another trait.

Fitness

The reproductive success of an organism, often measured by the number of offspring produced.

Quantitative Traits

Traits that are influenced by multiple genes and show measurable variation.

Gene Flow

The transfer of genetic variation from one population to another.

Variable selection

A process in which certain traits are favored by natural selection, leading to changes in allele frequencies in a population over time.

Gene flow

is essential for maintaining genetic diversity within populations and can affect local adaptation. Know as gene migration. It allows for the exchange of alleles between populations, which can introduce new genetic material and enhance the overall adaptability of species.