The Modern Synthesis

Abstract

The “modern synthesis” generally refers to the early to mid-century formulation of evolutionary theory that reconciled classical Darwinian selection theory with a newer population-oriented view of Mendelian genetics that attempted to explain the origin of biological diversity. It draws on the title of zoologist Julian S. Huxley’s book of 1943 titled Evolution: The Modern Synthesis, a semi-popular account of evolution that ushered in this “modern” synthetic view of evolution. Covering an interval of time approximately between 1920–1950, it also refers to developments in understanding evolution that drew on a range of disciplines that were synthesized or brought to consensus that generally include systematics, paleontology, and botany with a populational view of evolutionary genetics. Whether or not it served to unify the study of evolution, or to unify the disparate biological sciences—and whether or not it led to the emergence of a science of evolutionary biology, as some of its proponents have claimed—remains a topic for discussion. Though they do not refer to precisely the same things or share identical meanings, the phrase “modern synthesis” has overlapped with terms such as the “evolutionary synthesis,” coined and used especially by Ernst Mayr and William B. Provine, to refer to the historical event, as well as terms such as Neo-Darwinian theory or Neo-Darwinism (though criticism has been made regarding the latter term’s applicability to the mid-century developments in evolutionary theory). As Ernst Mayr noted, the term “Neo-Darwinism” was first coined and used by George John Romanes in 1895 to refer to a revision of Charles Darwin’s theory first formulated in 1859, which included Lamarckian inheritance. The extent to which the modern synthesis, and the evolutionary synthesis map with what is also called the synthetic theory, is open for discussion as is specific understanding of the term. For the most part, there is little in the way of consensus or agreement by scientists, philosophers, and historians as to what “the synthesis” (the abbreviated reference) precisely means, and what (if anything) specifically occurred of a general nature in studies of evolution, broadly construed, in the interval of time between 1920–1950.