Rat islands ‘a laboratory of future evolution’

Posted by ap507 at Feb 03, 2014 12:35 PM |
Dr Jan Zalasiewicz predicts rats will continue to grow and fill a ‘significant chunk’ of Earth’s emptying ecospace

The Pied Piper of Hamelin may have to start working overtime based on suggestions by Dr Jan Zalasiewicz (pictured) from the Department of Geology, who argues that rats will continue to get larger in size and population in the future as other mammals become extinct.

Malagasy giant rat
The Malagasy giant rat is an example of an islander rat that has adapted to its environment on the island of Madagascar in unique ways
Rats are one of the best examples of a species that humans have helped spread around the world. They have successfully adapted to many of the new environments they have found themselves in - they are now on most islands and continue to prosper and adapt. 

The result is that each island that rats are now present on is in effect a laboratory of future evolution – and each will produce different adaptive results over time.

Dr Zalasiewicz suggests that as ecospace empties, rats will continue to re-fill a significant chunk of it in the mid to far geological future - and that, given enough time, rats could grow to be at least as large as the capybara, the world’s largest rodent.

Occurrences of gigantism in rodents in the past can show the potential scope for evolution - the largest extinct rodent discovered so far, named the Josephoartegasia monesi, was larger than a bull, and weighed over a ton.

Dr Zalasiewicz explains more in this short clip.


Dr Zalasiewicz's comments have received widespread global media attention, including on BBC World News and from the Independent, the Daily Mail and the Metro, among others.


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