the visible hand

it is the theory which decides what can be observed – einstein

Newly evolved fur coat

Posted by ecoshift on August 27, 2009

Newly evolved fur coat a quick hit in Nebraska – life – 27 August 2009 – New Scientist

Deer mice have pulled off the opposite trick to the famous peppered moth, evolving a light coat to disguise themselves from predators. What’s more, they did it even though their ancestors had no genes for light coats….

Standing start

The amount of genetic variation… suggests the mutation occurred less than 10,000 years ago, Linnen says – after the formation of the Sand Hills.

“An older mutation would show lots of variation,” she says.

Normally, to achieve such a rapid evolutionary shift a species needs to have an alternative version of a gene already in circulation. A change in conditions – such as trees becoming darker as they get covered in soot, in the case of the peppered moth – can then provide the selection pressure that causes the alternate gene to spread. But in deer mice the new version of Agouti spread rapidly from a standing start.

Woodruff says that these “de novo” mutations – which occur after a species has encountered the situation where they will be useful, rather than before – may be more important for evolution than biologists think.

read more…

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