Evolution is a process of gradual change that takes place over many generations, during which various species of animals or plants slowly alter some of their characteristics. This course lays out the theory behind evolution and natural selection. We examine Charles Darwin's ideas surrounding variation, differential reproduction and heredity. We then study the impact of natural selection on the owl butterfly to give you a better practical understanding of the concept.

Deoxyribonucleic acid (DNA) is the basic unit of hereditary material in humans and almost all other organisms. Nearly every cell in a person's body has the same DNA. This course shows you how DNA codes all of our genetic information. We also study the variation in a species and investigate chromosomes, chromatids and chromatin. Chromosomes are single-stranded groupings of condensed chromatin and a chromatid is one half of two identical copies of a replicated chromosome.

In evolution, the success of a species can depend on changes to just one allele on one gene in one chromosome. This course helps you understand how variations occur naturally within a species as mutations and reproductions continue this process. You will also learn how DNA copies itself and turns into the proteins that make up all living organisms. This biology course explains why there is such diversity among plants and animals today and takes you through the processes that define the natural kingdom.