y life began in a “primordial soup” of organic molecules before evolving out of the oceans millions of years later. Today the “soup” theory has been overturned in a pioneering paper in BioEssays which claims it was the Earth's chemical energy, from hydrothermal vents on the ocean floor, which kick-started early life."
"Textbooks have it that life arose from organic soup and that the first cells grew by fermenting these organics to generate energy in the form of ATP. We provide a new perspective on why that old and familiar view won't work at all," said team leader Dr Nick lane from University College London. "We present the alternative that life arose from gases (H2, CO2, N2, and H2S) and that the energy for first life came from harnessing geochemical gradients created by mother Earth at a special kind of deep-sea hydrothermal vent -- one that is riddled with tiny interconnected compartments or pores."
So isn’t this interesting. A theory long held to be more or less bulletproof is suddenly rejected in favor of something rather different. I thought that kind of thing wasn’t supposed to happen? Of course, the story was familiar in part because intelligent-design advocates, and others, have long pointed out inadequacies in the soup concept.
In Signature in the Cell, Stephen Meyer writes about how back in 1985 he came across Thaxton, Bradley and Olson’s The Mystery of Life’s Origin, which “provided a comprehensive critique of the attempts that had been made to explain how the first life had arisen from the primordial ocean, the so-called pre-biotic soup.”
The soup-spilling team writing in BioEssays concentrates on the source of energy needed to power life into existence. Was it from UV radiation, as J.B.S. Haldane theorized in 1929? Or from a hydrothermal vent? This overlooks a much trickier problem: the source not of the relevant energy but the relevant biological information. As Meyer remarks in Signature, origin-of-life scenarios that “just transfer the information problem into the chemical soup itself” fit into a “clear pattern. Every attempt to explain the origin of biological information either failed because it transferred the problem elsewhere or ‘succeeded’ only by presupposing unexplained sources of information.”
Anyway, the lame retreat from a stance previously thumped with tremendous vigor sounds Pythonesque but no, a quick Internet search reveals it’s actually from Get Smart. Along with “Missed it by that much” and “Sorry about that, Chief,” “Would you believe…” was a repeated line from the classic 1960s TV show. It always introduced Agent Maxwell Smart’s attempt to climb down from an earlier, bolder claim in favor of increasingly pitiable ones: “I happen to be an expert in karate, Judo and tempura. Would you believe that I can break eight boards with one karate chop? No? Would you believe three boards? Would you believe a loaf of bread?”
But enough nostalgia. Read the ScienceDaily article here.
February 5, 2010
Evolution News and Views
A popular Darwinian meme is that humans and chimp genomes are ninety-something percent identical. It varies a bit, but usually hovers close to 99%. The meme hides all sorts of assumptions, of course, but the take home lesson for the headline reader is plain enough: we’re almost exactly the same as chimps.
Though the 99% number has received some qualifiers, and has even been referred to as a “myth” in Science, the basic idea remains firmly entrenched in the media collective consciousness.
But evidence seems to be piling up that the similarities are not nearly what has been advertised. Geneticist Richard Buggs has reflected on this, and has even predicted “that when we have a reliable, complete chimpanzee genome, the overall similarity of the human genome will prove to be close to 70% (and very far from 99%).”
It will be interesting to see how Buggs' prediction holds up over time. If he’s right, this will be one more switch from “meme” to “myth” in the Darwinian ledger.
I should confess that I haven’t followed this debate closely, simply because I don’t think that the meme, even if