The synergism hypothesis (revisited): a theory whose time has come?

A major theoretical issue in evolutionary biology over the past two decades has concerned the rise of complexity over time in the natural world, and a search has been underway for "a Grand Unified Theory" - as biologist Daniel McShea characterized it - that is consistent with Darwin's great vision. As it happens, such a theory already exists. It was first proposed many years ago in The Synergism Hypothesis: A Theory of Progressive Evolution, and it involves an economic (or perhaps bioeconomic) theory of complexity. Simply stated, cooperative interactions of various kinds, however they may occur, can produce novel combined effects - synergies - with functional advantages that may, in turn, become direct causes of natural selection. In other words, the Synergism Hypothesis is a theory about the unique combined effects produced by the relationships between things. I refer to it as Holistic Darwinism; it is entirely con - sistent with natural selection theory, properly understood. Because the Synergism Hypothesis was first proposed during a time when the genecentric, neo-Darwinist paradigm was domi nant in evolutionary biology, it was largely overlooked. But times have changed. Biologist Richard Michod has concluded that "cooperation is now seen as the primary creative force behind ever greater levels of complexity and organization in all of biology." And Martin Nowak has called cooperation "the master architect of evolution." Here I will revisit this theory in the light of the many theoretical developments and research findings in recent years that are supportive of it, including the role of symbiogenesis in evolution, the phenomenon of hybridization, lateral gene transfer in prokaryotes, "developmental plasticity" (evo-devo), epigenetic inheritance, the role of behaviour (and teleonomy) in evolution, and gene-culture coevolution. The Synergism Hypothesis is especially relevant to the evolution of humankind.