"Non-Darwinian Evolution" is a scientific paper written by Jack Lester King and Thomas H. Jukes and published in 1969. It is credited, along with

Motoo Kimura (November 13, 1924 – November 13, 1994) was a Japanese biologist best known for introducing the neutral theory of molecular evolution in 1968. He became one of the most influential theoretical population geneticists. He is remembered in ge ...

's 1968 paper "Evolutionary Rate at the Molecular Level", with proposing what became known as the

neutral theory of molecular evolution The neutral theory of molecular evolution holds that most evolutionary changes occur at the molecular level, and most of the variation within and between species are due to random genetic drift of mutant alleles that are selectively neutral. The ...

. The paper brings together a wide variety of evidence, ranging from

protein sequence Protein primary structure is the linear sequence of amino acids in a peptide or protein. By convention, the primary structure of a protein is reported starting from the amino-terminal (N) end to the carboxyl-terminal (C) end. Protein biosynthe ...

comparisons to studies of the Treffers mutator gene in ''

E. coli ''Escherichia coli'' ( )Wells, J. C. (2000) Longman Pronunciation Dictionary. Harlow ngland Pearson Education Ltd. is a gram-negative, facultative anaerobic, rod-shaped, coliform bacterium of the genus ''Escherichia'' that is commonly foun ...

'' to analysis of the genetic code to comparative

immunology Immunology is a branch of biology and medicine that covers the study of Immune system, immune systems in all Organism, organisms. Immunology charts, measures, and contextualizes the Physiology, physiological functioning of the immune system in ...

, to argue that most protein evolution is due to

neutral mutation Neutral mutations are changes in DNA sequence that are neither beneficial nor detrimental to the ability of an organism to survive and reproduce. In population genetics, mutations in which natural selection does not affect the spread of the mutatio ...

s and

genetic drift Genetic drift, also known as random genetic drift, allelic drift or the Wright effect, is the change in the Allele frequency, frequency of an existing gene variant (allele) in a population due to random chance. Genetic drift may cause gene va ...

. It was published in the journal ''

Science Science is a systematic discipline that builds and organises knowledge in the form of testable hypotheses and predictions about the universe. Modern science is typically divided into twoor threemajor branches: the natural sciences, which stu ...

'' on May 16, 1969. The idea of evolution at the molecular level being driven by the random processes of mutation and genetic drift, largely independent from

natural selection Natural selection is the differential survival and reproduction of individuals due to differences in phenotype. It is a key mechanism of evolution, the change in the Heredity, heritable traits characteristic of a population over generation ...

, was controversial at the time; the provocative title further emphasized the break with mainstream evolutionary thought, which was dominated by the

synthetic theory of evolution Modern synthesis or modern evolutionary synthesis refers to several perspectives on evolutionary biology, namely: * Modern synthesis (20th century), the term coined by Julian Huxley in 1942 to denote the synthesis between Mendelian genetics and s ...

, often referred to as "

Neo-Darwinism Neo-Darwinism is generally used to describe any integration of Charles Darwin's theory of evolution by natural selection with Gregor Mendel's theory of genetics. It mostly refers to evolutionary theory from either 1895 (for the combinations of D ...

". Although they argued for essentially the same conclusion as Motoo Kimura's earlier paper, King and Jukes criticized one of Kimura's central arguments, an estimate of the rate of amino acid change in proteins that according to Kimura would indicate an impossibly high

genetic load Genetic load is the difference between the fitness of an average genotype in a population and the fitness of some reference genotype, which may be either the best present in a population, or may be the theoretically optimal genotype. The average ...

if the changes were caused by natural selection. The paper was initially rejected by its reviewers (one thought it was trivial and the other thought it was totally wrong ), but was published after an appeal. This time, the reviewer was James F. Crow, Motoo Kimura's collaborator. Despite the intentionally inflammatory title and "antiauthoritarian tone"—which according to historian Michael R. Dietrich "undoubtedly struck a nerve", especially since King and Jukes worked at

UC Berkeley The University of California, Berkeley (UC Berkeley, Berkeley, Cal, or California), is a public land-grant research university in Berkeley, California, United States. Founded in 1868 and named after the Anglo-Irish philosopher George Berkele ...

during that period of political unrest—the paper acknowledges the significance of natural selection; it merely argues against

panselectionism Evolutionary thought, the recognition that species change over time and the perceived understanding of how such processes work, has roots in antiquity. With the beginnings of modern biological taxonomy in the late 17th century, two opposed id ...

(as advocated at the molecular level by

G. G. Simpson George Gaylord Simpson (June 16, 1902 – October 6, 1984) was an American paleontologist. Simpson was perhaps the most influential paleontologist of the twentieth century, and a major participant in the modern synthesis, contributing '' Tempo ...

and

Emil L. Smith Emil L. Smith (July 5, 1911 – May 31, 2009) was an American biochemist who studied protein structure and function as well as biochemical evolution. Initially intending to go into medicine, Smith became interested in biology and organic ch ...

in particular). From 1969 until the early 1970s, the concept of neutral mutations driven to fixation by genetic drift was known as "Non-Darwinian Evolution"; it was subsequently termed the "neutral theory of molecular evolution". "Non-Darwinian Evolution" generated considerable interest in neutral mutations, and became very influential in the field of

molecular evolution Molecular evolution describes how Heredity, inherited DNA and/or RNA change over evolutionary time, and the consequences of this for proteins and other components of Cell (biology), cells and organisms. Molecular evolution is the basis of phylogen ...

. The response by critics (including direct rebuttals by

Bryan Clarke Bryan Campbell Clarke (24 June 1932 – 27 February 2014) was a British Professor of genetics, latterly emeritus at the University of Nottingham. Clarke is particularly noted for his work on apostatic selection (which is a term he coine ...

and Rollin Richmond), and subsequent replies (by King and Jukes, Kimura, and others), marked the beginning of the neutralist/selectionist controversy. In the 1970s and 1980s, Kimura became the chief advocate of the neutral theory, but he adopted a number of King and Jukes' arguments and de-emphasized genetic load.

Notes and references

{{reflist 1969 in biology 1969 documents Biology papers History of evolutionary biology Evolutionary biology literature Molecular evolution Works originally published in Science (journal)

See also

Notes and references