DNA is a cells instruction book. It tells a cell how to build more of itself, or reproduce. DNA is where all of the information about an organism is stored.

Evolution is the process by which different kinds of living organisms are thought to have developed from earlier forms during the history of the earth. One example is how thousands of years ago, some types of monkeys started walking upright, and making tools, and that led to the creation of homosapiens, or humans.

The people who live in a certain town, city, or country is that area’s population.

A trait is a distinguishing quality or characteristic, typically belonging to a person. For example, one trait that you have is your eye’s design. Plants also have traits, such as a flower’s petal color.

Adaption is a change or the process of change by which an organism or species becomes better suited to its environment. As an example, most ducks have webbed feet to help them paddle through water more easily.

Mutation is the changing of a gene’s structure, resulting in a variant form that may be transmitted to subsequent generations, caused by the alteration of shingle base units in DNA, or the deletion, insertion, or arrangement of larger sections of genes or chromosomes.

A species is a group of living organisms of similar individuals capable of exchanging genes or interbreeding.

The process in which all members of a species die off, or become extinct.

DescriptionSelective breeding is the process by which humans use animal breeding and plant breeding to selectively develop particular phenotypic traits by choosing which typically animal or plant males and females will reproduce and have offspring together.

Natural Selection is the process whereby organisms better adapted to their environment tend to survive and produce more offspring.

Genetic variation is the difference in DNA among individuals. There are multiple sources of genetic variation, including mutation and genetic recombination.

Overproduction, in biology, means that each generation has more offspring than can be supported by the environment. Because of this, competition takes place for limited resources. Individuals have traits that are passed down to offspring.

Reproductive success is defined as an individual's production of offspring per breeding event or lifetime. This is not limited by the number of offspring produced by one individual, but also the reproductive success of these offspring themselves.

The struggle to survive is the competition in nature among organisms of a population to maintain themselves in a given environment and to survive to reproduce others of their kind.

A cladogram is a branching diagram showing the cladistic relationship between a number of species.

Fossils are the remains or impression of a prehistoric organism preserved in petrified form or as a mold or cast in rock.

Vestigial structures are various cells, tissues, and organs in a body which no longer serve a function.

The definition of a homologous structure is an organ or body part that appears in different animals and is similar in structure and location, but doesn't necessarily share the same purpose. An example of a homologous structure is the human arm as compared to the wing on a bird.