BSC2010 – Unit 3: Evolution

These flashcards cover key vocabulary related to evolution and its processes as outlined in BSC2010 Unit 3 lecture notes.

Evolution

A process by which species change over time through adaptation and natural selection.

Theory of Evolution

A well-substantiated explanation of how evolution occurs based on a wide range of evidence, differing from mere hypotheses.

Natural Selection

A mechanism of evolution proposed by Darwin, where organisms better adapted to their environment tend to survive and reproduce.

Adaptation

A trait that has evolved through natural selection, allowing an organism to better survive in its environment.

Heritability

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

Gene Flow

The transfer of genetic variation from one population to another, which can affect allele frequencies.

Genetic Drift

A mechanism of evolution that involves random changes in allele frequencies in a population.

Directional Selection

A mode of natural selection that favors one extreme phenotype over the mean or other extreme.

Stabilizing Selection

A mode of natural selection that favors intermediate variants and acts against extreme phenotypes.

Disruptive Selection

A mode of natural selection that favors individuals at both extremes of the phenotypic range.

Hardy-Weinberg Equilibrium (HWE)

A principle that predicts allele frequencies in a population will remain constant from generation to generation in the absence of evolutionary influences.

Neutral Mutations

Genetic changes that do not affect an organism's fitness and can accumulate over time.

Monophyletic Group

A group of organisms that includes an ancestor and all its descendants, a clade.

Homologous Traits

Traits inherited from a common ancestor, indicating evolutionary relationships.

Speciation

The evolutionary process by which new biological species arise.

Reproductive Isolation

A mechanism that prevents species from interbreeding and producing viable offspring.

Adaptive Radiation

The rapid evolution of diversely adapted species from a common ancestor.

Fossil Formation

The process by which organic material is preserved in rigid substances, such as rocks.

Phylogenetic Tree

A diagram that represents evolutionary relationships among biological species based on shared characteristics.

Molecular Clock

A technique used to estimate the time of evolutionary change based on mutation rates.