Unit 3 - Evolution of Life - 9th Grade

Acquired Trait

a trait that is not in your genes but is picked up from environmental factors.

Inherited Traits

traits that are passed from parents to their offspring.

Natural Selection

a process in which individuals that have certain inherited traits tend to survive and reproduce at higher rates than other individuals because of those traits.

Biological Fitness

a measure of the ability to survive and reproduce relative to other members of the population.

Trait

a characteristic that an organism can pass on to its offspring through its genes.

Adaptation

inherited characteristic that increases an organism's chance of survival.

Evolution

the gradual change in a species over time.

Genetic Diversity

a measure of the genetic variation among individuals in a population.

Biotic Factor

any living part of the environment.

Abiotic Factor

physical, or nonliving, factor that shapes an ecosystem.

Convergent Evolution

process by which unrelated organisms independently evolve similarities when adapting to similar environments.

Founder Effect

genetic drift that occurs when a few individuals become isolated from a larger population and form a new population whose gene pool composition is not reflective of that of the original population.

Gene Pool

combined genetic information of all the members of a particular population.

Genetic Drift

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

Geographic Isolation

isolation between populations due to physical barriers.

Homologous Structures

structures in different species that are similar because of common ancestry.

Reproductive Isolation

separation of a species or population so that they no longer interbreed and evolve into two separate species.

Speciation

the formation of new and distinct species in the course of evolution.

Analogous Structures

structures that do not have a common evolutionary origin but are similar in function.