Monday, September 3, 2007

A new way to study evolutionary paths

Finding: There is a new way to shed light on macroevolutionary research.
A team of scientists developed a novel methodological approach in evolutionary studies. Using the method they named 'genomic phylostratigraphy', its authors shed new and unexpected light on some of the long standing macroevolutionary issues, which have been puzzling evolutionary biologists since Darwin.


Problems with using Fossils
The only direct method of research in evolutionary history involves analyzing the fossil remains of once living organisms, excavated in various localities throughout of the world. However, that approach often cannot provide the full evolutionary pathway of some species, as it requires uncovering of many fossils from various stages of its evolutionary history. As the fossil record is imperfect, the evolution research fundamentally hinges on luck factor in discovering the adequate paleontological sites.

New Approach - Snapshots of the evolutionary path
However, the RBI team proposed a novel and interesting approach to bypass this obstacle. Namely, they suggested that the genome of every extant species carries the ‘snapshots’ of evolutionary epochs that species went trough. What's even more important, they also developed the method which enables evolution researchers to readily convert those individual 'snapshots’ into the full-length 'evolutionary movie' of a species.

The approach on flies
Applying their new methodology on the fruit fly genomic data they tackled some of the most intriguing evolutionary puzzles - some of which distressed even Darwin himself. First, they demonstrated that parts of the living organism exposed to the environment – so called ‘ectoderm’ - are more prone to evolutionary changes. Further, they explained the evolutionary origin of the ‘germ layers’, the primary tissue forms that form during the first days after the conception of a new animal, and from which subsequently all other tissues are developed. Finally, they discovered the potential genetic trigger for the 'Cambrian explosion', a major global evolutionary event on the planet, when some 540 million years ago almost all animal forms known today suddenly 'appeared'.

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