Evolution Terms

• Evolution- The gradual change in a species over time
• Species- A group of similar organisms that can breed and produce fertile offspring
• Fitness- how well an organism can survive and reproduce in its environment
• 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.
• Adaptation- An inherited trait that helps an individual survive and reproduce better in its environment
• Variation- Any difference between individuals of the same species.
• Gene pool- All the genes, including all the different alleles for each gene, that are present in a population at any one time
• Speciation- the formation of new and distinct species in the course of evolution.
• Analogous Structures- Similar function but different structure - does not show common ancestry - Ex: butterfly wing and bat wing)
• Homologous chromosomes- structures in different species that are similar because of common ancestry.
• Vestigial Structures- remnant of a structure that may have had an important function in a species' ancestors, but has no clear function in the modern species.
• Overproducing of offspring- producing more offspring than can survive
• Biological Resistance- the natural or genetic ability of an organism to avoid or repel attack by biotic agents - passed on to offspring.
• Charles Darwin- English natural scientist who formulated a theory of evolution by natural selection
• Ancestral Trait- more primitive characteristic that appeared in common ancestors.
• Inherited trait- a characteristic that is passed from parent to offspring.
• Population- a group of individuals that belong to the same species and live in the same area
• Descent with Modification- principle that each living species has descended, with changes, from other species over time
• Survival of the fittest (Natural Selection)- process by which individuals that are better suited to their environment survive and reproduce most successfully
• Stabilizing selection- favors average version of the trait
• Directional Selection- form of natural selection in which the entire curve moves; occurs when individuals at one end of a distribution curve have higher fitness than individuals in the middle or at the other end of the curve
• Disruptive Selection- form of natural selection in which two extremes of a phenotypic distribution become more common while the intermediate forms decrease in frequency
• Embryology- the study of embroy's and their development
• Fossil evidence for evolution- looking at historical organisms for change and similarities to present day organisms
• Molecular evolution- comparing DNA sequences from different species to determine how they evolved over time