(Visited 106 times, 1 visits today)FacebookTwitterPinterestSave分享0 Evolutionists speculating about the Last Universal Common Ancestor (LUCA) begin with lots of L.U.C.K.Without doubt, ATP synthase is one of the most astonishing and elegant nano-machines of the cell, a proton-powered rotary engine pumping out life’s energy currency nonstop (see animations at CMI and Evolution News). How it could have arisen by blind, unguided processes is rarely addressed in the origin-of-life community. Nick Lane, a biochemist at University College London, has a knack for oversimplifying the problem. A few years ago (8/11/10), we saw him shocking a colleague by dismissively stating, “all that the cells need to do to generate ATP is to plug an ATPase through the membrane” as if that was a cakewalk. Last year he quipped, “Life is, in effect, a side-reaction of an energy-harnessing reaction” (2/13/13). Now, he’s done it again; he and his colleagues just assume that ATP synthase showed up when it was needed to plug up a leaky cell.In PLoS Biology, Nick Lane and two colleagues model how the last universal common ancestor (LUCA) might have split into two kingdoms, bacteria and archaea (eukaryotes came later, they speculate, from a merger of the two). They actually begin further back, when the first life was trying to emerge from a hydrothermal vent. In that scenario, protons or sodium ions might have provided a steady energy source across the original membrane (wherever that came from). As LUCA tried to swim free, though, it needed to harness its energy production. Richard Robinson explains the situation in a companion article on PLoS Biology:In modern cells, the proton gradients that drive ATP synthesis are generated by proton pumps in the membrane [primarily ATP synthase]. However, like the membranes themselves, these pumps differ in archaea and bacteria. One possibility is that LUCA could have used proton gradients but not generated them itself and therefore might have relied on natural proton gradients [like hydrothermal vents]. However, that leads straight to another problem. The influx of protons down a natural gradient can’t go on forever, or even very long, since the buildup of positive charge halts the electrostatic drive behind the process—hence, the authors reasoned, the value of a leaky membrane.In a nutshell, Nick Lane’s team figured that LUCA had a leaky membrane that allowed some protons to leak in and out, but ATP synthase engines embedded in the membrane kept the gradient going. As the two kingdoms went separate ways, they took their proton pumps with them.But wait! Where did the ATP synthase come from? They had just talked about natural proton gradients, like hot fluids from a hydrothermal vent flowing into alkaline ocean water. Did the molecular motor appear out of nowhere—as if by magic? Apparently. Robinson doesn’t bat an eye as he watches it emerge:As a source of proton gradients, LUCA most likely relied on naturally occurring pH differences like those found in the oceans, where alkaline fluids seep from deep sea vents into relatively acidic seawater. The model they built then posited a cell in contact with a constant flow of protons on one side (from seawater), a constant flow of alkaline fluid on the other (potentially from a vent), and a leaky membrane containing an ATP synthase. They found that with a 3-unit pH gradient (i.e., a 1000-fold concentration gradient of protons) and the ATP synthase comprising 1% of the membrane, the cell could drive synthesis of ATP.We’re reminded of what David Nicholls said in 2010, commenting on this kind of audacity found in Lane’s book with the audacious title Science, Power, Sex, Suicide: Mitochondria and the Meaning of Life. That’s where Lane gave the statement, “all the cell needs to do to generate ATP is to plug an ATPase through the membrane.” Nicholls remarked,Any bioenergeticist who has followed the elucidation of the extraordinary structure and mechanism of the mitochondrial ATP synthase over the past decade will pause at the word ‘all,’ because the ATP synthase—with its spinning rotor massaging the surrounding subunits to generate ATP—is without doubt the most amazingly complex molecular structure in the cell.There’s an old joke about three guys on an island trying to open a tuna can. The last one suggests, “Assume a can opener.” Just like that, Nick Lane has assumed an ATP synthase, the “most amazingly complex molecular structure in the cell” showed up in LUCA’s membrane to keep the proton gradients going. Or maybe it recalls Sidney Harris’s cartoon of a student writing a complex derivation on the blackboard, including a step, “Then a miracle happens.” Unlike the professor in the cartoon who insists the student elaborate on that step, Robinson didn’t mind Lane’s leap of faith. Maybe some science reporters did. Let’s check:“The difference in the concentration of protons across these two environments enabled protons to flow into the cell, driving the production of a molecule called adenosine triphosphate (ATP) which powered the growth of cells, just as it does today.” (press release from University College London; they might be expected to promote their own guy’s views)“This drives the production of a molecule called adenosine triphosphate (ATP), which makes modern-day cells grow” (The Daily Mail, UK)“Our ancestor’s ‘leaky’ membrane answers big questions in biology” (The Jersey Tribune)“Meet your maker: Homing in on the ancestor of all life” (New Scientist)A search on “Ancestor’s ‘leaky’ membrane‘ shows this story echoed around the world on 13,800 websites—doubtless without critique—in a spirit of rejoicing at this marvelous advance in modern science’s ability to describe life’s earliest progress.A darling of BBC News science programs, Nick Lane gets away with murdering scientific rigor. With a sweep of his hand, ATP synthase appears, simply because life needed a permanent way to keep its energy production going. This is worse than “assume a can opener.” It’s assuming a Ferrari.Where are the philosophers? Where are the logicians? Where is anybody with respect for truth? Why do these sophoxymoroniacs get a pass in the world’s media? Is it because they know how to work differential equations and speak jargon? Is it because they seem so confident and charismatic? Is it because universal evolutionary common ancestry is modernity’s substitute religion? That’s it: “Meet your maker,” New Scientist says. Our modern institutions long ago ousted the God of creation from their minds and hearts. Since nature abhors a vacuum, they filled that God-shaped void with an idol named LUCA, who gives life to all things, from whom all blessings flow.Except for the western clothes and jargon, Nick Lane is no different than a shaman in the jungle holding his tribe captive with great-sounding words of wisdom, full of sound and fury, signifying nothing. “The last common ancestor of all life was not a free-living cell at all, but a porous rock riddled with bubbly iron-sulphur membranes that catalysed primordial biochemical reactions,” he whispers over the campfire, his captives listening wide-eyed at every holy word (10/19/09, #3). The prophets in the media dutifully dumb down the prophecy to the surrounding villages: “Our oldest ancestor was a proton-powered rock.” Ooh! Aah. Such wisdom. How much better off we are since we boiled the Christian missionary in the pot!