Exciting things are happening in evolutionary science. The sliding pictures below show two insect species that each have alternative forms of their appearance; these are examples of something called phenotypic plasticity. The gaudy commodore butterfly’s colouration is seasonally dependent, with a blue winter morph and an orange summer one. Harlequin bugs exhibit a range of light and darker casts in their colour patterns that are induced by the temperatures encountered during the bugs’ development. These animals’ features are therefore determined partly by environmental conditions, not just their genetic make up. This is important, because that responsiveness to environmental conditions makes plasticity a mechanism of evolution, and part of a scientific revolution called the extended evolutionary synthesis.
Image credits: left 1 & 2 right 3 & 4
In the 19th century the theory of natural selection, developed independently by Alfred Wallace and Charles Darwin, provided a mechanism for evolution and, in doing so, revolutionised biological science. Genetic science subsequently added a mechanism to account for the biological variation upon which natural selection was proposed to operate. That combination of two critical processes has, with good reason, been the generally accepted core mechanism of evolutionary biology for over eighty years. But cracks are appearing in some aspects of that model. One aspect of this is that new research has identified alternative mechanisms of biological variation; biological adaptation has been shown to emerge directly and specifically in response to environmental pressure, rather than arising from entirely random genetic change, and astonishing discoveries have revealed that, contrary to the consistent findings of decades of science, organisms can alter their genetic nature in order to adjust to environmental conditions. The implications of these newly emerging processes are profound, provocative and exciting; they alter the story of how living things evolve.
This website is an introduction to and information source for this dramatic new evolutionary biology. We examine particularly those aspects of the extended evolutionary synthesis that involve environmentally generated adaptation and evolution. Frustration that knowledge of this new view of evolution, whilst gaining acceptance among scientists, was not reaching the wider population, led us to write a description that makes the field accessible and interesting to a non-specialist audience. Comprising a series of illustrative examples in animals, this comprehensive explanation forms the core of the site. Using the three links below, you can read it off or online, as a longform text, or guided by a series of short summaries.
The knowledge we present here fascinated and stimulated us; we hope it does the same for you.
Image credits
- Cherry Flowers, https://uk.inaturalist.org/people/cherryflowers https://uk.inaturalist.org/observations/172301088 [↩]
- Andrew Hankey, https://uk.inaturalist.org/people/andrew_hankey https://uk.inaturalist.org/photos/13127653 [↩]
- Sheldon Logan, https://uk.inaturalist.org/people/muddphoto https://uk.inaturalist.org/photos/327275557? [↩]
- Eric Alan Isaacson, https://uk.inaturalist.org/people/eaisaacson https://uk.inaturalist.org/observations/190367523 [↩]