UF scientists discover evolutionary origin of fins, limbs

Gainesville, Florida: - Performance on the dance floor may notalways show it, but people are rarely born with two left feet. We havegenes that instruct our arms and legs to grow in the right places andpoint in the right directions. They also provide for the spaces betweenour fingers and toes and every other formative detail of our limbs.

Evolutionarilyspeaking, the genetic instructions used to construct and position ourlimbs were being perfected more than half a billion years ago infishes, not along the sides of the body where the fins that precededhuman arms and legs sprouted, but at the midline that runs along thebackbone and belly.

This midline - think of the dorsal, tail andanal fins of a fish - is where the genetic template to produce finsoriginated, about 100 million years before paired fins evolved andabout 200 million years before paired fins evolved into limbs,according to University of Florida genetics researchers. The findings,published online today in the journal Nature, also provide insight intothe evolutionary history of genes involved in human birth defects.[evolution, origin]

[The Nature paper is currently available here but the link won't work for long because it's an advance publication - email if you have any problems.]

technorati tags: florida, genes, limbs, fishes, fins, body, midline, template, nature, evolution, history, origin

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