Evolution is any change across successive generations in the inherited characteristics of biological populations. Evolutionary processes give rise to diversity at every level of biological organisation, including species, individual organisms and molecules such as DNA and proteins.

Life on Earth originated and then evolved from a universal common ancestor approximately 3.7 billion years ago. Repeated speciation and the divergence of life can be inferred from shared sets of biochemical and morphological traits, or by shared DNA sequences. These homologous traits and sequences are more similar among species that share a more recent common ancestor, and can be used to reconstruct evolutionary histories, using both existing species and the fossil record. Existing patterns of biodiversity have been shaped both by speciation and by extinction.

Charles Darwin was the first to formulate a scientific argument for the theory of evolution by means of natural selection. Evolution by natural selection is a process that is inferred from three facts about populations: 1) more offspring are produced than can possibly survive, 2) traits vary among individuals, leading to differential rates of survival and reproduction, and 3) trait differences are heritable. Thus, when members of a population die they are replaced by the progeny of parents that were better adapted to survive and reproduce in the environment in which natural selection took place. This process creates and preserves traits that are seemingly fitted for the functional roles they perform. Natural selection is the only known cause of adaptation, but not the only known cause of evolution. Other, nonadaptive causes of evolution include mutation and genetic drift.

Jerry Allen Coyne (born December 30, 1949) is an American professor of biology, known for his commentary on the intelligent design debate. A prolific scientist, he has published dozens of papers, elucidating on the theory of evolution. He is currently a professor at the University of Chicago in the Department of Ecology and Evolution. His concentration is speciation and ecological and evolutionary genetics, particularly as they involve the fruit fly, Drosophila. He is the author of the standard text Speciation and the bestselling science popularization Why Evolution is True and maintains a website by the same name.

Coyne graduated with a B.S. at the College of William & Mary in 1971. He then earned a Ph.D. in biology at Harvard University, studying under Richard Lewontin, and went on to do a postdoctoral fellowship at the University of California, Davis. In 1989, he was awarded the Guggenheim Fellowship.

Coyne has served as Vice President of the Society for the Study of Evolution (1996) and as Associate Editor of Evolution (1985–1988; 1994–2000) and The American Naturalist (1990–1993). He currently teaches evolutionary biology, speciation, genetic analysis, social issues and scientific knowledge, and scientific speaking and writing.

William Sanford "Bill" Nye (born November 27, 1955), popularly known as Bill Nye the Science Guy, is an American science educator, comedian, television host, actor, mechanical engineer, and scientist. He is best known as the host of the Disney/PBS children's science show Bill Nye the Science Guy (1993–1998) and for his many subsequent appearances in popular media as a science educator.

William Sanford Nye was born in Washington, D.C., the son of Jacqueline (née Jenkins; c. 1920–2000), a codebreaker during World War II, and Edwin Darby "Ned" Nye (died 1997), also a World War II veteran whose experience in a Japanese prisoner of war camp led him to become a sundial enthusiast. Nye is a fourth-generation Washington, D.C. resident on his father's side of the family. After attending Lafayette Elementary and Alice Deal Junior High in the city, he was accepted to the private Sidwell Friends School on a partial scholarship, graduating in 1973. He studied mechanical engineering at Cornell University, where one of his professors was Carl Sagan, and graduated with a Bachelor of Science in 1977. He was awarded an honorary doctorate by The Johns Hopkins University in May 2008. In May 2011, Nye was awarded an Honorary Doctor of Science degree from Willamette University where he was the keynote speaker for that year's commencement exercises.

Kenneth Alfred Ham (born 20 October 1951) is a prominent Australian young-Earth creationist and advocate for a literal interpretation of the Book of Genesis.

Ken Ham obtained a bachelor's degree in Applied Science, with emphasis in Environmental Biology, through the Queensland Institute of Technology and, in order to begin teaching science in Australian public schools, a diploma in Education from the University of Queensland. On 30 December 1972, he married Marilyn ("Mally"), whom he describes as a "very, very submissive, supportive wife" who has "always supported me five million percent." The Ham couple have five children — four are married and one lives with them in the Cincinnati area and have seven grandchildren. In 1979, Ham co-founded what was to be later known as the Creation Science Foundation (CSF) in Queensland, Australia with John Mackay.

Ham worked for the Institute for Creation Research (ICR), a leading young-Earth organisation. In 1994, with the assistance of what is now Creation Ministries International (Australia), Ham and colleagues Mark Looy and Mike Zovath set up Creation Science Ministries, later renamed Answers in Genesis. The Christian ministry specialises in young Earth creationism and promotes the belief that the initial chapters in Genesis should be taken as literally true and historically accurate. He then began raising "tens of millions of dollars" to build the ministry.