In order to recognize a change in the shape of the debate over evolution among scientists you must first understand what evolution is or more precisely what the theory of evolution is. Also, you need to recognize the nature of the differing scientific disciplines involved in the study of evolution. Ernst Mayr, called by many the Darwin of the 20th century, documented both of these facts in his book One Long Argument: Charles Darwin and the Genesis of Modern Evolutionary Thought. Here Mayr defines both what constitutes the theory of evolution, or more precisely the theories of evolution, and the shape of the debate over evolution among scientists from the inception of the theories of evolution in 1859 until the 1990s.
So first, what constitutes the theory of evolution? The theory of evolution is actually composed of five separate theories: 1) evolution as such (organisms are transformed in time); 2) common descent or common ancestry (all life descended from a single origin of life); 3) multiplication of species (macroevolution or speciation); 4) gradualism (new species are formed by numerous, successive, slight modifications); and 5) natural selection (survival of the fittest).
Second, what is the nature of the differing scientific disciplines involved in the study of evolution? Broadly speaking there are three scientific disciplines that specifically study evolution: genetics, systematics, and paleontology. Systematists and paleontologists are so-called naturalists in that they study the natural world with its multiplicity of living forms and fossils and try to make sense of their observations in accordance with the five theories of evolution. Geneticists on the other hand study the microscopic intricacies of individual organisms, whether living or fossilized, and try to make sense of their discoveries in accordance with the five theories of evolution.
Because these disciplines are so different technically the naturalists remained mostly uninformed about the discoveries of genetics and vice a versa. This situation led to differing conclusions concerning three of the five theories of evolution.
“Evolution as such” and “common ancestry” were accepted by all. However, the theories of multiplication of species, gradualism, and natural selection were widely debated among scientists until the so-called Modern Evolutionary Synthesis (MS) that developed over the period from 1936 to 1950.
The nature of the MS was one of mutual education and house cleaning. Architects of the MS developed a common language so naturalists and geneticists could communicate. They clarified concepts and aspects of evolution such that all had a common understanding of evolution. This mutual education resulted in perhaps the most important achievement of the MS; the universal acceptance of natural selection as the mechanism of evolution and genetic recombination and mutations as the material of evolution subjected to natural selection.
The process of house cleaning resulted in the refutation of three theories that were the primary competitors to natural selection: 1) the inheritance of acquired characteristics (neo-Lamarckism); 2) vitalism or a built-in drive toward evolutionary progress; and 3) saltations or sudden mutations resulting in new life forms. The refutation of these three theories ostensibly solidified the acceptance within the scientific community of the debated Darwinian theories of speciation, gradualism, and natural selection.
Achieving this purported universal acceptance of natural selection and the refutation of competing theories to natural selection defined the shape of the debate during the first half of the 20th century. From 1950 to the present, the MS has served as a façade erected between the scientific community and the public domain in order to keep serious scientific debates over evolution from public scrutiny. For public consumption (such as in education, the courts and the popular media) scientists publicly affirm Darwin’s five theories of evolution as proven theories beyond any reasonable doubt and no longer legitimately subject to debate.
However, as technologies and methodologies have continually improved from 1950 to the present, the shape of the debate has taken on a drastically new form. At the heart of the new debate is the Modern Synthesis itself and specifically the theories of common ancestry, speciation, gradualism, and natural selection.
Carl Woese, a leading biological scientist and expert in origin of life studies at the University of Illinois, claims the Modern Synthesis with its dogmatic thinking has “failed” and “led to a premature declaration of victory in the struggle to understand the evolutionary process.” He further claims that scientists must shed the “fetters” of classical biological thinking (MS) and begin anew with a “tabula rasa” (clean slate) if the scientific understanding of the evolutionary process is to advance. He specifically refutes the theory of common ancestry with these words: “The time has come for biology to go beyond the Doctrine of Common Descent. Neither it nor any variation of it (invoking, say, several primordial forms) can capture the tenor, the dynamic, the essence of the evolutionary process that spawned cellular organization.”
In July 2008 a group of 16 widely known evolutionary biologists and philosophers of science met in Altenberg, Austria. According to the Altenberg 16, as they were called, “the core theoretical framework underlying the biological sciences is undergoing ferment.” This current fermentation of debates is threatening to overflow the MS façade. In fact, these 16 scientists offered a very critical assessment of the MS, refuting many of its foundational concepts.
Participants Massimo Pigliucci and Gerd Muller, representative of the group, assert that:
1) The “central dogma” (gene centrism) of the Modern Evolutionary Synthesis (MS) has been clearly demolished. [This central dogma maintained that the information flow of biological systems was only one-way, i.e., from DNA RNA proteins, thus rendering the inheritance of acquired characteristics as impossible];
2) Gradualism has been replaced with non-gradualism (i.e., saltations);
3) Externalism (emphasis on natural selection and environment) has been replaced with “internalism,” i.e., “the organisms themselves represent the determinants of selectable variation and innovation.” Natural selection acts only as a “background” condition and not as a causal or determinative agent; and
4) Gene centrism necessarily disappears, fading into the new view that “genes are followers” (i.e. inheritance of acquired characteristics).
These claims refute the MS theories of speciation, gradualism, and natural selection. Coupled with Woese’s refutation of common ancestry, scientists are once again strongly contesting the validity of four of Darwin’s five theories of evolution.
For the first time common ancestry has come under attack, creating a major change in the shape of the debate. The MS façade is beginning to crack under the strain of this new shape of the debate. It just may soon crumble leaving only the axiomatic theory “evolution as such” standing. And, what scientifically speaking is the difference in saying “in the beginning God” or “in the beginning evolution?”
Charles E. Warren,