Sir Julian Sorell Huxley FRS (22 June 1887 – 14 February 1975) was an English evolutionary biologist, humanist and internationalist. He was a proponent of natural selection, and a leading figure in the mid-twentieth century evolutionary synthesis. He was Secretary of the Zoological Society of London (1935–1942), the first Director of UNESCO, and a founding member of the World Wildlife Fund.

Huxley was well known for his presentation of science in books and articles, and on radio and television. He directed an Oscar-winning wildlife film. He was awarded UNESCO's Kalinga Prize for the popularisation of science in 1953, the Darwin Medal of the Royal Society in 1956, and the Darwin–Wallace Medal of the Linnaean Society in 1958. He was also knighted in that same year, 1958, a hundred years after Charles Darwin and Alfred Russel Wallace announced the theory of evolution by natural selection. In 1959 he received a Special Award of the Lasker Foundation in the category Planned Parenthood – World Population. Huxley was a prominent member of the British Eugenics Society and its president from 1959–1962.

Joseph "Joe" Felsenstein (born 1942) is Professor in the Departments of Genome Sciences and Biology and Adjunct Professor in the Departments of Computer Science and Statistics at the University of Washington in Seattle. He is best known for his work on phylogenetic inference, and is the author of Inferring Phylogenies, and principal author and distributor of the package of phylogenetic inference programs called PHYLIP. Closely related to his work on phylogenetic inference is his introduction of methods for making statistically independent comparisons using phylogenies (Felsenstein, 1985).

Felsenstein did his undergraduate work at the University of Wisconsin–Madison where he did undergraduate research under James F. Crow. He then did doctoral work under Richard Lewontin in the 1960s, when he was at the University of Chicago, and did a postdoc at the Institute of Animal Genetics in Edinburgh prior to becoming faculty at the University of Washington.

In addition to his work in phylogenetics, he is also noted for his work in theoretical population genetics, including studies on selection, migration, linkage, speciation, and the coalescent.

Terence Kemp McKenna (November 16, 1946 – April 3, 2000) was an American philosopher, psychonaut, researcher, teacher, lecturer and writer on many subjects, such as human consciousness, language, psychedelic drugs, the evolution of civilizations, the origin and end of the universe, alchemy, and extraterrestrial beings.

Terence McKenna grew up in Paonia, Colorado. He was introduced to geology through his uncle and developed a hobby of solitary fossil hunting in the arroyos near his home. From this he developed a deep artistic and scientific appreciation of nature.

At age 16, McKenna moved to Los Altos, California to live with family friends for a year. He finished high school in Lancaster, CA. In 1963, McKenna was introduced to the literary world of psychedelics through The Doors of Perception and Heaven and Hell by Aldous Huxley and certain issues of The Village Voice that talked about psychedelics.

McKenna claimed that one of his early psychedelic experiences with morning glory seeds showed him "that there was something there worth pursuing." In an audio interview Terence Mckenna claims to have started smoking cannabis regularly during the summer following his 17th birthday.

Charles Robert Darwin, FRS (12 February 1809 – 19 April 1882) was an English naturalist. He established that all species of life have descended over time from common ancestors, and proposed the scientific theory that this branching pattern of evolution resulted from a process that he called natural selection.

Darwin published his theory with compelling evidence for evolution in his 1859 book On the Origin of Species, overcoming scientific rejection of earlier concepts of transmutation of species. By the 1870s the scientific community and much of the general public had accepted evolution as a fact. However, many favoured competing explanations and it was not until the emergence of the modern evolutionary synthesis from the 1930s to the 1950s that a broad consensus developed in which natural selection was the basic mechanism of evolution. In modified form, Darwin's scientific discovery is the unifying theory of the life sciences, explaining the diversity of life.

Darwin's early interest in nature led him to neglect his medical education at the University of Edinburgh; instead, he helped to investigate marine invertebrates. Studies at the University of Cambridge encouraged his passion for natural science. His five-year voyage on HMS Beagle established him as an eminent geologist whose observations and theories supported Charles Lyell's uniformitarian ideas, and publication of his journal of the voyage made him famous as a popular author.