8.1 Molecular Evolution

Flashcards covering key concepts from the lecture on molecular evolution, genes, and genomes.

Genome

The full set of genes an organism contains, including noncoding regions of DNA.

Mutation

A change in the DNA sequence that may result from replication errors.

Nucleotide Substitution

A type of mutation where one nucleotide is replaced by another in the DNA sequence.

Synonymous Substitution

A nucleotide substitution that does not affect the amino acid sequence of a protein.

Nonsynonymous Substitution

A nucleotide substitution that changes the amino acid sequence of a protein.

Phenotype

The observable physical or biochemical characteristics of an organism, determined by its genetic makeup.

Transposable Elements

DNA sequences that can move from one location to another within the genome, also known as 'jumping genes.'

Codon

A sequence of three nucleotides in DNA or RNA that specifies an amino acid in a protein.

Lateral Gene Transfer

The transfer of genes from one species to another, bypassing traditional modes of reproduction.

Epigenetics

The study of changes in gene expression that do not involve changes to the underlying DNA sequence.

Hox Genes

A group of regulatory genes that control the body plan of an embryo along the head-tail axis.

Gene Duplication

The process by which a segment of DNA is copied, resulting in two or more copies of that gene.

Molecular Clock

A method of estimating the time of evolutionary divergence between species based on the rate of molecular change.

Pseudogene

A nonfunctional sequence of DNA that resembles a gene but has lost its protein-coding ability.

Natural Selection

The process where organisms better adapted to their environment tend to survive and produce more offspring.

Neutral Theory

The hypothesis that most evolutionary changes at the molecular level are caused by random drift of mutant alleles that are neutral.

Homologous Genes

Genes that share a common ancestry and often retain similar functions in different organisms.

Polyploidy

The condition of having more than two complete sets of chromosomes.

Convergent Evolution

The independent evolution of similar traits in different lineages.