LZHS Bio I: Topic 9: Natural Selection & Evolution

Evolution

Change in a kind of organism over time; process by which modern organisms have descended from ancient organisms.

Natural Selection

the principle that, among the range of inherited trait variations, those contributing to reproduction and survival will most likely be passed on to succeeding generations

Artificial Selection

Selection by humans for breeding of useful traits from the natural variation among different organisms

Genetic Variation

The variety of different types of genes in a species or population.

Mutation

change in a DNA sequence that affects genetic information

Competition

the struggle between organisms to survive in a habitat with limited resources

Predator

The organism that does the killing in a predation interaction

Prey

An organism that is killed and eaten by another organism

Competitive (Selective) Advantage

a genetic advantage that improves an organism's chance of survival, usually in a changing environment

Heterozygous Advantage

a condition in which being Aa, or carrying oftentimes a bad recessive copy of the gene, proves to be an advantage in a particular environment, thus keeping the allele in population Ex: being heterozygous for sickle cell anemia in areas infested with malaria

Fitness

Ability of an organism to survive and reproduce in its environment

Adaptation

inherited characteristic that increases an organism's chance of survival

Common Ancestor

The shared ancestor of new, different species that arose from one population

Gene Frequency

the ratio of a particular allele to the total of all other alleles of the same gene in a given population.