Tuesday, July 28, 2009

Have Primal Evolutionary Manipulations Been Found?

...as a biologist, seemed to find their curious marking unusually puzzling and provocative, though to my geological eye it looked not unlike some of the ripple effects reasonably common in the sedimentary rocks...On the other hand, the prevalence of very early life forms was singular in the highest degree.... and Lake fell back on mythology for a provisional name - jocosely dubbing his finds "The Elder Ones." -- Mountains of Madness, HPL

Oldest Animal Fossils Found in Lakes, Not Oceans

Conventional wisdom has it that the first animals evolved in the ocean.

Now researchers studying ancient rock samples in South China have found that the first animal fossils are preserved in ancient lake deposits, not in marine sediments as commonly assumed.

These new findings not only raise questions as to where the earliest animals were living, but what factors drove animals to evolve in the first place.

For some 3 billion years, single-celled life forms such as bacteria dominated the planet. Then, roughly 600 million years ago, the first multi-cellular animals appeared on the scene, diversifying rapidly.

The oldest known animal fossils in the world are preserved in South China's Doushantuo Formation. These fossil beds have no adult specimens - instead, many of the fossils appear to be microscopic embryos.

"Our first unusual finding in this region was the abundance of a clay mineral called smectite," said researcher Tom Bristow, now at the California Institute of Technology in Pasadena. "In rocks of this age, smectite is normally transformed into other types of clay. The smectite in these South China rocks, however, underwent no such transformation and have a special chemistry that, for the smectite to form, requires specific conditions in the water - conditions commonly found in salty, alkaline lakes."

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