The History in Our Genes

These flashcards cover key concepts from the lecture 'The History in Our Genes,' focusing on molecular clocks, genetic evolution, and selection processes.

Molecular clock

A method used to estimate the time of divergence between species by analyzing the evolution rates of different DNA segments.

Pseudogenes

DNA sequences that resemble functional genes but do not produce a protein; they evolve faster and accumulate mutations more easily.

dN/dS ratio

A comparative measure of the rate of nonsynonymous (dN) to synonymous (dS) substitutions, used to infer selection pressure on genes.

Synonymous mutations

Mutations that do not change the amino acid sequence of a protein, often evolving faster than nonsynonymous mutations.

Nonsynonymous mutations

Mutations that change the amino acid sequence of a protein, typically subject to negative selection due to their potential deleterious effects.

Natural selection

The process through which certain traits increase in frequency in a population due to their advantageous effects on survival and reproduction.

Positive selection

A form of natural selection that increases the frequency of beneficial alleles in a population, leading to a higher rate of nonsynonymous substitutions.

Substitution saturation

A phenomenon where multiple mutations occur at the same site, leading to misleading estimates of genetic divergence.

HIV-1

A group of human immunodeficiency viruses that evolved from simian immunodeficiency viruses in chimpanzees and gorillas.

Lentivirus

A genus of retroviruses that infects mammals, characterized by a long incubation period.