Evolutionary theory challenged by new research

The idea evolution takes place in rapid spurts is under fire.

(PhysOrg.com) -- New research from the University of Reading overturns conventional views on the nature of evolution, arguing that mammals did not develop into their many different forms in one early and rapid burst of evolution but rather found many different evolutionary routes.

It is widely assumed that species often diverge rapidly early in their evolution, and that this is followed by a longer, drawn-out period of slower evolutionary fine-tuning.

Explanations for this pattern suppose that mammals moved into a largely unoccupied niche and geographical space as they came to be the dominant vertebrate group on Earth. Then, as time went on, niche space and unexplored geographical regions became scarce, reducing opportunities for diversification.

However, the research led by Professor Mark Pagel, in conjunction with Dr Chris Venditti and Dr Andrew Meade, shows that there is no necessary connection between the rates at which new species emerge and the underlying rates of evolution of their features. Thus, the majority of mammal species, including two of the most prevalent orders of mammals (the rodents and bats), have no history of substantial and sustained increases in the rates at which they evolve.

Instead, these species achieved high rates of ‘speciation' or the production of new species, even though their rates of evolution were close to normal for mammals.