In “Calcified clue to ancient photosynthesis” (Nature, 2011/07/06), Katharine Sanderson reports:
Mat of microbes contains calcium carbonate that could only have formed through photosynthesis.The most direct evidence yet for ancient photosynthesis has been uncovered in a fossil of a matted carpet of microbes that lived on a beach 3.3 billion years ago.
[ … ]
“One of many mysteries about the early fossil record is the lack of calcified examples of microbial filaments, which are usually found in shallow marine contexts consistent with photosynthesis,” says Martin Brasier, an expert on ancient biological processes at the University of Oxford, UK. Brasier is cautious about the results, saying he would like to see independent confirmation of the work.
Another view
Other ancient mats have been studied, but Westall says evidence that they photosynthesized has been indirect — either being assumed from their carbon-isotope composition, which Westall argues can also come from non-photosynthetic microbes, or by looking closely at the mat’s structure and seeing microbe-like structures.
Anyone remember the schoolroom sound bite that a century ago many scientists doubted Darwin because Lord Kelvin had said there wasn’t enough time for evolution, the Earth only being 100 million years old. Well, Earth turned out to be 4.2 billion years old. Therefore, there was enough time! End of story.
But what if life processes existed from at or near the beginning? Who or what comes to the rescue now? The multiverse?
File with “Plenty of time for Darwinian evolution” Oh and, copy editor, check that title, will you?