Greening the Cambrian Explosion
Some scientists came up with an idea that simple green plants may have invaded the land earlier than thought, and that this might have helped speed up the rise of animals in the Cambrian explosion. “The plants were only tiny mosses and liverworts, but they would have had a profound effect on the planet,” said New Scientist. “They turned the hitherto barren Earth green, created the first soils and pumped oxygen into the atmosphere, laying the foundations for animals to evolve in the Cambrian explosion that started 542 million years ago.” Science Daily piped in, saying that the scientists “believe they have found the trigger for the Cambrian explosion.”
The scientists are Paul Knauth (Arizona State) and Martin Kennedy (UC Riverside). In their paper in Nature,1 they did not even mention the Cambrian explosion or the evolution of animals at all. Here was the only cryptic reference to it:
The contrasting isotope data between 850 Myr ago and the Neoproterozoic suggest that the terrestrial expansion of photosynthesizing communities preceded the significant climate perturbations of the late Precambrian glaciations, and was followed by a rise of O2 (ref. 26) and a secular change in terrestrial sediment composition. The onset of significant biotically enhanced terrestrial weathering would have increased the flux of lithophile nutrient elements and clay minerals to continental margins. This would have increased production and burial preservation of organic C towards modern values and consequently facilitated the stepwise rise in atmospheric O2 necessary to support multicellularity. The terrestrial expansion of an extensive, simple land biota indicated by the isotope data may thus have been a critical step in the transition from the Precambrian to the Phanerozoic world.
Their claim that plants colonized the land earlier than thought was based entirely on isotope data in limestones – not on any fossils of plants. In the same issue of Nature,2 Eric Hand understood that this is a controversial claim. At first he gave them the benefit of the doubt: “A thick, green carpet of photosynthetic life, on the scale of that seen today, exploded across Earth 850 million years ago – much earlier than thought – a new study suggests.” So for one thing, he not only failed to offer a solution for the Cambrian explosion of animals, he added a second explosion of plants. That seems another hurdle for Darwinian theory.
He also attributed to Knauth and Kennedy the conclusion that “The greening of ancient Earth could thus be indirectly responsible for the sudden evolution, beginning about 600 million years ago, of larger respirating animals with oxygen-hungry cells,” but then he acknowledged that the evidence is only indirect.
Hand reminded his readers that other studies contradict the rise of land plants so early. “The study contradicts other work that looks to the oceans, rather than land, to justify the same isotopic data.” The claim also flies in the face of the popular “Snowball Earth” scenario that postulates glaciers in the tropics the same time Knauth and Kennedy say plants were invading the land. He lists other problems: (1) “there isn’t much evidence for widespread plant life until around 400 million years ago, and (2) “to have the effect on the carbonate record that they see, the ancient photosynthetic life would have needed to be operating on the scale that it is today – a worldwide carpeting of green.” Where is the evidence for that? Such a carpet should have left its trace in the fossil record – “something for posterity,” Hand put it. A paleobiologist said it would have been unavoidable for plants to leave their traces in the rocks.
Despite these problems, the popular press gave prominence to the impression that Knauth and Kennedy had solved the problem of the Cambrian explosion. Science Daily said that the greening of the land “virtually set the table for the later explosion of life through the development of early soil that sequestered carbon, led to the build up of oxygen and allowed higher life forms to evolve.” In this “brave new world” of free oxygen, Knauth “explained” that “Early animals would have loved breathing it as they expanded throughout the ocean of this new world.” New Scientist pointed to a couple of problems that put a “fly in the ointment” of their idea, but still gave it good press: “They turned the hitherto barren Earth green, created the first soils and pumped oxygen into the atmosphere, laying the foundations for animals to evolve in the Cambrian explosion that started 542 million years ago.”
Science Daily made a couple of comments that historians of science and philosophers of science might want to analyze: “A key element to this scenario is not so much what the researchers saw in the data, but what was missing.” (This refers to a gap in the plots of limestone isotope data that Knauth and Kennedy interpreted as meaningful to the timing of the arrival of land plants.) The article also quoted Knauth saying, “Our work presents a simple, alternative view of the thousands of carbon isotope measurements that had been taken as evidence of geochemical catastrophes in the ocean.” What must the scientists who took those measurements be thinking of this re-interpretation?
1. L. Paul Knauth and Martin J. Kennedy, “The late Precambrian greening of the Earth,” Nature advance online publication 8 July 2009 | doi:10.1038/nature08213; Received 20 June 2008; Accepted 18 June 2009; Published online 8 July 2009.
2. Eric Hand, “When Earth greened over,” Nature, 460, 161 (2009), doi:10.1038/460161a, July 8, 2009.
Knauth said, “The isotopes are screaming that this happened in the Neoproterozoic.” That’s not what they are screaming. They are screaming, “Stop lying about us!” Good grief, this “virtually set the table for the later explosion of life,” they said. What kind of goofball story is this? They have portrayed Lady Luck as a waitress, calling, “Here, chance! Here, randomness! Eat some raw carbon and oxygen and turn into a trilobite!”
Are you outraged by this shameful misrepresentation of what the paper actually said (and what the evidence showed) compared to what the popular media reported? Two Darwin-drunk scientists took some indirect data, based on gaps, that ran in the face of thousands of measurements by others, and stretched it through a long series of mights, maybes and perhapses into a scenario about when green plants first colonized the land, all based on an incestuous relationship between evolutionary theory and evolutionary geology, which they then cooked up and served as a foundation for explaining the Cambrian explosion. Outrageous.
The story goes completely beyond any stretch of evidence. But look what the Darwin-drunk media said about it: these two guys “found the trigger” of the Cambrian explosion and discovered what “laid the foundation” for the sudden emergence of complex animals, as if finding some bricks on the ground explains the emergence of a skyscraper. Here is your tax money at work. This storytelling circus was funded by NASA and the National Science Foundation.
The reporters at New Scientist and Science Daily just swallowed whole what these two scientists said, without any sniffing or tasting first to see if it was wholesome or not. Then they regurgitated what the self-serving Arizona State press release put out to honor their own, and added some cloves and ginger on top to make the green barf look appealing. How come Darwinists themselves don’t recognize this as despicable crud? Why do the Darwin-drunk media get away with it? For the same reason that corrupt, lying, self-promoting, politicians stay in power, pushing the same policies that history has repeatedly shown are doomed to failure. We let them.