300C_Lec_10_Variation_Cont

Mutation

The source of all genetic variation, resulting from random errors during DNA replication, recombination, or repair.

Beneficial mutation

A mutation that increases the fitness of its carriers.

Deleterious mutation

A mutation that decreases the fitness of an organism.

Neutral mutation

A mutation that does not affect the fitness of an organism.

Point mutations

Nucleotide-pair substitutions that may be synonymous or nonsynonymous.

Missense mutation

A type of mutation where one amino acid is replaced by another.

Nonsense mutation

A mutation that changes an amino acid codon into a stop codon, usually leading to a nonfunctional protein.

Frameshift mutation

A mutation caused by insertions or deletions that shift the reading frame, often resulting in nonfunctional proteins.

Gene duplication

A mutation that results in multiple copies of a gene in the genome.

Neofunctionalization

A process where a duplicated gene acquires a new function.

Subfunctionalization

A process where duplicated genes divide the original functions between them.

Inversion

A chromosomal rearrangement where the gene sequence is reversed.

Supergene

A group of neighboring genes that are inherited together due to close linkage.

Genetic drift

A mechanism that limits the amount of genetic diversity a population can hold.

Natural selection

The process by which beneficial mutations are preserved in populations.

Homologous recombination

The process of exchange of genetic material between homologous chromosomes during meiosis.

Aneuploidy

A condition of having an abnormal number of chromosomes, leading to extra copies of some chromosomes.

Polyploidization

Duplication of all genes in the genome, resulting in multiple sets of chromosomes.

Redundancy in genetic code

A feature of the genetic code where multiple codons can code for the same amino acid.

Alleles

Versions of the same gene or DNA segment that differ in nucleotide sequence.

Gene copy number variation

Differences in the number of copies of a particular gene in individuals.

Hox genes

A family of genes that regulate the development of body plans in animals.

Genetic variation

Diversity in gene frequencies within a population.

Mutation accumulation experiment

An experiment where individuals are selected at random to study the effects of mutations in the absence of natural selection.

Selection pressures

Environmental factors that influence which individuals survive and reproduce.

RNA viruses

Viruses that use RNA as their genetic material, often exhibiting high mutation rates.

Evolving fitness

How an organism's ability to survive and reproduce changes over time due to genetic mutations.