Evolution

Acquired Trait

The character developed in an individual as a result of environmental influence.

Artificial Selection

An evolutionary process in which humans consciously select for or against particular features in organisms.

Adaptation

Organisms adjust to new environments or to changes in their current environment.

Natural Selection

Process by which organisms with favorable traits survive and reproduce.

Fitness

The strength from survival and reproduction.

Evolution

The process of organisms changing over time to adapt to their environment.

Microevolution

Small changes.

Macroevolution

Larger changes, leads to speciation.

Derived Traits

Those that just appeared (by mutation) in the most recent ancestor (e.g., white mice turning brown because of the environment).

Homologous Structures

Similar structures evolved from a common ancestor.

Analogous Structures

Similar structures in unrelated organisms.

Vestigial Structures

Structures that do not have a major function.

Biogeography

The branch of biology that deals with the geographical distribution of plants and animals.

Stabilizing Selection

Individuals are more fit to survive; they stabilize (medium).

Directional Selection

A single phenotype is favored, causing the allele frequency to continuously shift in one direction.

Disruptive Selection

Occurs when both extreme traits are favored in an environment.

Sexual Selection

The process by which individuals compete for access to mates and fertilization opportunities.

Divergent Evolution

Related species becoming more dissimilar.

Convergent Evolution

Unrelated species becoming more similar due to the same kind of environmental pressures.

Coevolution

Two organisms evolving together develop adaptations to benefit one another or coloration to hide or shape to allow for pollination.

Gradualism

The evolution of species by the gradual accumulation of small genetic changes.

Punctuated Equilibrium

Pattern of evolution in which long stable periods are interrupted by short bursts of change.

Adaptive Radiation

Example of divergent evolution; radiates throughout the environment.

Embryology

The branch of biology concerned with the study of embryos.

Comparative Anatomy

The study of similarities in the anatomical structure of different species.

Biochemical Evidence

A technique used to determine relationships.

HMS Beagle

Ship that took Charles Darwin to the Galapagos Islands to study natural selection.

Galapagos Islands

Recent volcanic origin; species came here from South America because they were specifically adapted to the Galapagos.

Gene Pool

The combination of all the genes (including alleles) present in a reproducing population or species.

Genetic Drift

The change in frequency of an existing gene variant in the population due to random chance.

Bottleneck Effect

Dramatic reduction of a population's size.

The Founder Effect

A small group of founding individuals colonize a new location, reduced genetic diversity usually occurs.

Mutation

A change in DNA sequence.

Geographical Isolation

The physical separation of populations of organisms from one another due to geographical barriers.

Behavioral Isolation

When species are reproductively isolated from others due to differences in behavior.

Prezygotic Isolation

Prevent fertilization from happening (behavioral, geographical, ecological).

Postzygotic Isolation

A sterile offspring is made (e.g., liger).

Law of Superposition

One of the principles of geology scientists use to determine the relative ages of rock strata, or layers.

Allopatric Speciation

Physical barriers divide populations (most common).

Sympatric Speciation

No physical barriers divide populations, but can occur within a population.

Endosymbiotic Theory

How Eukaryotic cells came from prokaryotic cells; may have entered the cell through parasitism.

Antibiotic Resistance

Bacteria can fight against antibiotics if the medicine was used incorrectly.

Relative Dating

To determine which things are older or younger based on their relationships (Stratum).

Radiometric Dating

Using half-lives of radioactive isotopes.