Genetic Determinism - The Modern Synthesis

The Modern Synthesis

Following the rediscovery of Mendel's principles of genetics, several theorists such as RA Fisher, JBS Haldane, Sewall Wright, Ernst Mayr and Theodosius Dobzhansky contributed to the synthesis of Mendel and Darwin's concept of natural selection. In contrast to Weismann, the modern synthesis rejected the notion that the organism is ultimately reducible to physical principles. According to Mayr, the organism responds to a dual causation, one based on laws of physics, the other based on a genetic program. Thus the organism reflects not just the mechanics of its constituent parts but the phylogenetic history encoded in its genes. Genetic information both reflects a species' descent and directs an organism’s development. The key to genes is not their chemical makeup but the information they carry. According to esteemed researcher Christiane Nusslein-Volhard, what distinguishes genes from proteins is that genes are chemically identical and differ only in terms of their sequence of nucleic acids and the information encoded in that sequence.