Taboo Biology: Epigenetics
Throughout the twentieth century, one of the strongest taboos in biology was against the inheritance of acquired characteristics, sometimes called Lamarckian inheritance, after the pioneering evolutionary biologist Jean-Baptiste Lamarck (1744-1829). Lamarck proposed that adaptations by plants and animals could be passed on to their offspring. In this respect, Charles Darwin was a convinced Lamarckian. He believed that habits acquired by individual animals could be inherited, and played an important part in evolution: “We need not … doubt that under nature new races and new species would become adapted to widely different climates, by variation, aided by habit, and regulated by natural selection.” In this sense, the inheritance of habits by morphic resonance is in good accordance with Darwinism, as opposed to neo-Darwinism. Darwin provided many examples of the inheritance of acquired characters in his book The Variation of Animals and Plants Under Domestication, and also proposed a theory to explain it, the theory of pangenesis.
Modern neo-Darwinism was established in the 1940s, and firmly rejected the Lamarckian aspect of Darwin’s theory. Neo-Darwinians asserted that genes were passed on without modification from parents to offspring, apart from rare random mutations. Any kind of Lamarckian modification of the genes was impossible. By contrast, in the Soviet Union under Stalin, the inheritance of acquired characteristics became official doctrine under Trofim Lysenko. The debate degenerated into polemics and denunciations, and in the West the taboo against the inheritance of acquired characteristics was reinforced.
In his rejection of Lamarckism, Richard Dawkins, the leading modern exponent of neo-Darwinism, is clear about his feelings: “To be painfully honest, I can think of few things that would more devastate my world view than a demonstrated need to return to the theory of evolution that is traditionally attributed to Lamarck.”
Evidence in favor of the inheritance of acquired characteristics continued to accumulate throughout the twentieth century, but was generally ignored. However, soon after the turn of the millennium, the taboo began to lose its power with a growing recognition of a new form of inheritance, called epigenetic inheritance. The prefix epi means “over and above.” Epigenetic inheritance does not involve changes in the genes themselves, but rather changes in gene expression. Characteristics acquired by parents can indeed be passed on to their offspring. For example, water fleas of the genus Daphnia develop large protective spines when predators are around; their offspring also have these spines, even when not exposed to predators.
Several molecular mechanisms of epigenetic inheritance have been identified. Changes in the configuration of the chromatin—the DNA-protein complex that makes up the structure of chromosomes—can be passed on from cell to daughter cell. Some such changes can also be passed on through eggs and sperm, and thus become hereditary. Another kind of epigenetic change, sometimes called genomic imprinting, involves the methylation of DNA molecules. There is a heritable chemical change in the DNA itself, but the underlying genes remain the same.
Epigenetic inheritance also occurs in humans. Even the effects of famines and diseases can echo down the generations. The Human Epigenome Project was launched in 2003, and is helping to coordinate research in this rapidly growing field of inquiry.
Morphic resonance provides another means by which the inheritance of acquired characteristics can occur. Its effects can be distinguished experimentally from other forms of epigenetic inheritance.
Want to learn more about epigenetics? Great video introduction here. Excerpted from Morphic Resonance – The Nature of Formative Causation, by Rupert Sheldrake