Heritable trait variation is that due to genetic variation. Heritability refers to the proportion of trait variation that can be attributed to genetic factors. Genetic correlation refers to the proportion of total genetic variation in two traits that is shared. Sexual selection refers to a mode of natural selection in which certain alleles are favored over others because of their effects on acquiring
mates rather than survival. Alleles are alternative versions of genetic variants at a given locus. Mutation load refers to an individual’s aggregate burden of deleterious mutations (rare alleles) across the genome, which is heritable Selleckchem Selumetinib across generations. Good gene indicators are traits that reflect underlying genetic fitness, for example low mutation load. Pleiotropic genes influence more than one trait. Cross-trait assortative mating occurs when two different Sunitinib datasheet traits correlate across mates, for example males of above-average height mating with females of above-average intelligence. Extended twin-family designs take advantage of the genetic relatedness between multiple
family members, for example, twins, their spouses, and their parents, in order to investigate the importance of environmental and genetic influences on one or multiple traits. Sexual dimorphism refers to the difference between male and female phenotypes. Fisher’s Fundamental Theorem states that ‘the rate of increase in fitness of any organism at any time is equal to its genetic variance in fitness at that time.’ It has often been interpreted to mean that
additive genetic variation should be low in traits related to fitness. Phenotypes are observable characteristics or traits of an organism. Recessive/additive/dominant refer to how likely an allele is to be expressed in the phenotype. At a diallelic locus, a fully recessive allele will not be expressed unless both copies are present, while the fully dominant allele will be fully expressed with only one copy. Many dominance relationships are partial rather than full, yielding a spectrum of dominance or recessivity. Additivity is intermediate between fully recessive and fully dominant. SNP (single-nucleotide polymorphism) is a type of allele where a single-nucleotide Fludarabine chemical structure position is variable in the population. Often, the term ‘SNP’ is used for loci where the minor allele frequency is >1% and ‘mutation’ when the minor allele frequency is <1%. Homozygosity occurs when two copies of the same allele are present at a locus, as opposed to heterozygosity, in which the two alleles at a locus are different. Runs of homozygosity are stretches of contiguous SNPs (e.g. 60+) that are consistently homozygous along some stretch of an individual’s genome. Linkage studies test for coinheritance of alleles and traits within families.