Academic journal article Perspectives on Science and Christian Faith

New Ideas in Evolutionary Biology: From NDMS to EES

Academic journal article Perspectives on Science and Christian Faith

New Ideas in Evolutionary Biology: From NDMS to EES

Article excerpt

The neo-Darwinian modern synthesis (NDMS) has been the bedrock of evolutionary theory for many decades. But the NDMS has proven limited and out of date with respect to several areas of biological research. A new extended evolutionary synthesis (EES), which takes into account more complex interactions between genomes, the cell and the environment, allows for a reexamination of many of the assumptions of the NDMS. To the standard paradigm of slow accumulation of random point mutations as the major mechanism of biological variation must now be added new data and concepts of symbiosis, gene duplication, horizontal gene transfer, retrotransposition, epigenetic control networks, niche construction, stress-directed mutations, and large-scale reengineering of the genome in response to environmental stimuli. There may be implications for Christian faith in this opening of evolutionary theory to a broader and more exciting view of Darwin's great theory.

Theoretical evolutionary biology has been undergoing a crescendo of transformations in recent years. After a long period of general acceptance of the traditional paradigm for how evolution works, new data and concepts from many fields of biological science have begun to challenge the status quo of evolutionary theory. There is no question that evolution occurred, but some of the new ideas are potentially exciting for Christians searching for reconciliation of their belief in a Creator with acceptance of the science of evolution.

Darwin's profound concept of evolution by natural selection remains the best explanation for the diversity of life. Darwin's theory was about natural selection of biological variants. He knew from careful observation that all species contained variants and that selective breeding could magnify variation in animals or plants. He knew nothing about the source of such variation, nor about the basis of the heritability of specific variant traits. Mendel's finding of variant alleles leading to different phenotypes was central to the understanding of the source of variation that could drive evolution.

The Neo-Darwinian Synthesis

In the middle of the twentieth century, even before the chemical nature of the gene was known, biologists were examining mutations in experimental systems of bacteria in order to answer questions about purpose and chance in mutation production. Do bacteria tend to specifically mutate those genes that would help them survive an environmental stress such as starvation or exposure to toxic drugs, or do they simply generate random mutations and then undergo selection according to their fitness? Salvador Luria and Max Delbruck addressed this question in the 1940s with an elegant system called "fluctuation analysis." (1)

The results of these experiments were clear: mutations were random, and the resulting alleles were then selected for their relative fitness. This finding contributed to the emerging neo-Darwinian "modern synthesis" (NDMS), in which molecular genetics plays the key role in the production of phenotypic variation, and purpose is replaced by chance in the production of variation, which is the first stage of evolution. The next five decades of research into the fundamental mechanisms of cellular and molecular biology confirmed and vastly extended our knowledge of genetic structure and function, including the details of DNA mutations.

In any field of science, if a theory is any good, it will allow for a logical consolidation of isolated fragments of data or disparate knowledge from several fields into a functional and meaningful picture. The NDMS did just that by combining observations from paleontology and evolutionary biology with genetics and molecular biology. However, the advantage of the NDMS, its simplicity as a unifying theory combining evolution and genetics, has also become its weakness, since it fails to accommodate some of the latest information on the enormous complexity of biological function at the deepest level. …

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