Evolution and Population Genetics

Flashcards based on lecture notes about evolution, natural selection, and population genetics.

What is taxonomy?

The branch of biology concerned with identifying, naming, and classifying species.

What is a binomial?

A two-part Latinized name given to each species.

What is a genus?

A group of closely related species.

What explanation is accepted by present-day biologists for the origin of the diversity of life?

The evolutionary theory, proposed by Charles Darwin.

What is natural selection?

Individuals with certain inherited traits are more likely to survive and reproduce than are individuals with other traits.

What is descent with modification?

Present-day species are the descendants of ancient ancestors, which they still resemble in some ways.

What are fossils?

Imprints or remains of organisms that lived in the past.

What is homology?

Similarity resulting from common ancestry.

What are vestigial structures?

Remnants of features that served important functions in an organism’s ancestors.

What is mutation?

A change in the nucleotide sequence of DNA.

What is a population?

A group of individuals of the same species that live in the same area and interbreed.

What is a gene pool?

All copies of every type of allele, at every locus, in all members of the population.

What is genetic equilibrium (Hardy-Weinberg equilibrium)?

A non-evolving population is in this state.

What is microevolution?

A generation-to-generation change in allele frequencies of a population.

What are the three main causes of evolutionary change?

Natural selection, genetic drift, and gene flow.

What is genetic drift?

A change in the gene pool of a small population due to chance.

What is bottleneck effect?

Results from a drastic reduction in population size.

What is the founder effect?

Likely when a few individuals colonize an isolated habitat; represents genetic drift in a new colony.

What is gene flow?

Genetic exchange with another population.

What is sexual selection?

A form of natural selection in which individuals with certain traits are more likely than other individuals to obtain mates.

What is sexual dimorphism?

A distinction in appearance between males and females not directly associated with reproduction or survival.

What is directional selection?

Shifts the overall makeup of a population by selecting in favor of one extreme phenotype.

What is disruptive selection?

Can lead to a balance between two or more contrasting phenotypic forms in a population.

What is stabilizing selection?

Favors intermediate phenotypes, occurs in relatively stable environments, and is the most common.