Bio Chapter 15 Quiz

Artificial selection

Directed breeding to produce offspring with desired traits.

Natural selection

Some competitors are better equipped for survival than others, those less equipped would die.

Derived traits

New traits that show up at some point in the fossil record and then continue to show up afterward

Ancestral traits

Old traits that are found throughout the fossil record though modified over time

Homologous structures

Anatomically similar structures inherited from a common ancestor

Vestigial structures

The reduced forms of functional structures in other organisms

Analogous structures

Features of different species that are similar in function but not necessarily in structure and which do not derive from a common ancestral feature.

Embryo

Early, pre-birth stage of an organism's development

Biogeography

The study of the distribution of plants and animals around the world

Fitness

A measure of how successful an organism is in its environment

Camouflage

An organism that blends into its environment

Mimicry

A species evolves to resemble another species

Hardy- Weinberg principle

When allelic frequencies remain constant, a population is in genetic equilibrium.

Founder Effect

A group of individuals with a different allele frequency than the original population becomes isolated.

Genetic drift

A change in the allelic frequencies in a population that results from chance

Bottleneck

Results when population declines to a very small population and then rebounds.

Stabilizing selection

Operates to eliminate extreme expressions of a trait when the average expression leads to higher fitness.

Directional selection

Increases the expression of an extreme version of a trait and increases fitness.

Disruptive selection

Removes individuals with average traits, but keeps individuals with extreme traits.

Sexual selection

Drives change in the frequency of a trait based on the ability to attract a mate.

Prezygotic isolating

Before fertilization and prevents reproduction by making fertilization unlikely

Postzygotic isolating mechanisms

After fertilization and ensures that the resulting hybrid stays infertile

Allopatric speciation

Populations are divided by a physical barrier causing multiple different species to evolve from one species

Sympatric speciation

Populations are not divided by a physical barrier causing multiple different species to evolve from one species

Adaptive radiation

A large number of species arise from a common ancestor because of an ecological opportunity

Convergent evolution

Species that aren't related evolve similar traits even though they live in different parts of the world.

Gradualism

Evolution that proceeds in small, gradual steps

Punctuated equilibrium

Evolution that happens more quickly in bigger steps