_________________________ a. A change in genes that causes a change in a particular trait _________________________ b. Describes a species that no longer has any living representatives _________________________ c. A trait that a species develops over generations which helps it to survive _________________________ d. a unit of DNA that determines a specific trait in the organism _________________________ e. The survival of organisms best fit for the environment _________________________ f. Changes in living things over time _________________________ g. Remains of organisms that lived in the past _________________________ h. Best suited to survive in its environment _________________________ i. The biologist who developed and offered evidence of the theory of Natural selection