Summarised by Centrist
The extended evolutionary synthesis (EES), championed in Evolution Evolving by Kevin Lala and colleagues, offers a fresh perspective on evolution.
This approach argues that development, influenced by environmental conditions, plays a role in driving evolution alongside natural selection.
The book challenges the mid-twentieth-century modern synthesis, which frames evolution solely around random genetic mutations and their selection.
The way an organism grows and changes depends on the environment it lives in, and this also influences how it evolves over time.
For example, there’s a fish called the Mexican tetra. Some live in caves and are blind because they don’t need eyes in the dark. Others live on the surface and have normal eyesight.
However, researchers observed that if the surface-dwelling fish are kept in darkness for two years, they start developing traits like the blind cave fish, such as better fat storage (helpful in places where food is hard to find).
This happens because the darkness “switches on” certain genes that change how the fish grows. Over generations, genetic changes that support these traits become permanent, showing that evolution follows where environmental changes lead.
They argue that understanding “developmental biases” is essential to predicting how traits evolve.
Read more over at Nature (paywalled)
Image: H. Zell
