how evolutionary theory develops

I’ve just come across an excellent post by evolutionary biologist Massimo Pigliucci, talking about how evolutionary theory has developed since the ‘modern synthesis’ was set out. (And of course, the modern synthesis was an advance on Darwin’s orginal theory of natural selection as the agent of descent with modification – science changes as it accommodates new data & new explanations.) Because I think it’s important for you to realise that evolutionary theory does move with the times, I’ve pasted part of his post here.

The basic idea is that there have been some interesting empirical discoveries, as well as the articulation of some new concepts, subsequently to the Modern Synthesis, that one needs to explicitly integrate with the standard ideas about natural selection, common descent, population genetics and statistical genetics (nowadays known as evolutionary quantitative genetics). Some of these empirical discoveries include (but are not limited to) the existence of molecular buffering systems (like the so-called "heat shock response") that may act as "capacitors" (i.e., facilitators) of bursts of phenotypic evolution, and the increasing evidence of the role of epigenetic (i.e., non-genetic) inheritance systems (this has nothing to do with Lamarckism, by the way). Some of the new concepts that have arisen since the MS include (but again are not limited to) the idea of "evolvability" (that different lineages have different propensities to evolve novel structures or functions), complexity theory (which opens the possibility of natural sources of organic complexity other than natural selection), and "accommodation" (a developmental process that may facilitate the coordinated appearance of complex traits in short evolutionary periods).

Nothing to suggest that evolution is ‘a theory in crisis’ (or any of the other standard anti-evolutionary red herrings), but rather, an excellent example of just how willing scientists are to discuss new work and integrate it with an existing framework. Science changes and develops over time.

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