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.

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.

Zakir Abdul Karim Naik (Urdu: ذاکر عبدالکریم نائیک; born 18 October 1965) is an Indian public speaker on the subject of Islam and comparative religion. He is the founder and president of the Islamic Research Foundation (IRF), a non-profit organisation that owns the Peace TV channel based in Dubai, UAE. He is sometimes referred to as a televangelist. Before becoming a public speaker, he trained as a doctor. He has written two booklets on Islam and comparative religion. He is regarded as an exponent of the Salafi ideology; he places a strong emphasis on individual scholarship and the rejection of "blind Taqlid", which has led him to repudiate the relevance of sectarian or Madh'hab designations, all the while reaffirming their importance.

Zakir Abdul Karim Naik was born on 18 October 1965 in Mumbai, India. He attended St. Peter's High School in Mumbai. Later he enrolled at Kishinchand Chellaram College, before studying medicine at Topiwala National Medical College and Nair Hospital and later the University of Mumbai, where he obtained a Bachelor of Medicine and Surgery (MBBS). His wife, Farhat Naik, works for the women's section of the IRF.