Macroevolution and Population Genetics

These flashcards cover key concepts related to macroevolution and population genetics, including definitions and important theories in evolutionary biology.

Macroevolution

The broad patterns of evolution above the species level, often focusing on changes that occur over long periods.

Fossils

Remains or impressions of ancient organisms preserved in rock, serving as direct evidence of evolution.

Homologous Structures

Anatomical features in different species that are similar due to shared ancestry.

Molecular Record

The analysis of genetic material, such as DNA and proteins, to identify evolutionary relationships between organisms.

Allele Frequency

The relative frequency of an allele at a genetic locus in a population.

Hardy-Weinberg Equilibrium

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

Natural Selection

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

Genetic Drift

Random changes in allele frequencies in a population from one generation to the next, due to chance events.

Mutation

A change in the nucleotide sequence of an organism's DNA, providing a source of genetic variation.

Non-random Mating

A situation where individuals select mates based on specific traits, leading to changes in allele frequencies.

Gene Flow

The transfer of alleles or genes from one population to another, often through migration.

Directional Selection

A type of natural selection that favors one extreme phenotype over the others.

Stabilizing Selection

A type of natural selection that favors intermediate variants by acting against extreme phenotypes.

Disruptive Selection

A type of natural selection that favors extreme values for a trait over intermediate values.

Population Genetics

The study of genetic variation within populations and involves the examination of allele frequency distribution and change under the influence of the evolutionary processes.

Genotype Frequency

The proportion of individuals in a population that have a particular genotype.

Phenotype Frequency

The proportion of individuals in a population that exhibit a particular phenotype.

Founder Effect

Reduced genetic diversity that results when a population is formed from a small number of individuals.

Cladogram

A diagram that shows the evolutionary relationships among a group of organisms.

Guppies

Small freshwater fish that are often studied in evolutionary biology for observing natural selection.