A key riddle surrounding the origin of biological molecules like RNA and DNA is how they first came together billions of years ago from simple precursors but a study appearing in the Journal of Biological Chemistry says researchers in Italy have reconstructed one of the earliest evolutionary steps yet; generating long chains of RNA from individual subunits using nothing but warm water.
Many researchers believe that RNA was one of the first biological molecules present, before DNA and proteins, but there has been little success in recreating the formation on RNA from simple "prebiotic" molecules that likely were present on primordial earth billions of years ago.
Ernesto Di Mauro and colleagues found that ancient molecules called cyclic nucleotides can merge together in water and form polymers over 100 nucleotides long in water ranging from 40-90 °C –similar to water temperatures on ancient Earth.
Cyclic nucleotides like cyclic-AMP are very similar to the nucleotides that make up individual pieces of DNA or RNA (A, T, G and C), except that they form an extra chemical bond and assume a ring-shaped structure. That extra bond makes cyclic nucleotides more reactive, though, and thus they were able to join together into long chains at a decent rate (about 200 hours to reach 100 nucleotides long).
This finding is exciting as cyclic nucleotides themselves can be easily formed from simple chemicals like formamide, thus making them plausible prebiotic compounds present during primordial times. Thus, this study may be revealing how the first bits of genetic information were created.A key riddle surrounding the origin of biological molecules like RNA and DNA is how... more
New Zealand born evangelical Christian Ray Comfort, aka "the banana man", has published a new 150th anniversary edition of Charles Darwin's On the Origin of Species, complete with a 50-page creationist introduction.
Working with child actor Kirk Cameron, Comfort and his lackeys will be distributing 50,000 copies of the book for free on 50 college campuses around the US tomorrow.
"All we want to do is propose the opposing and correct view," says Growing Pains star Cameron, who, as far as I can tell, has equally impeccable credentials in evolutionary biology as Comfort--meaning, of course, none whatsoever.
Comfort is known as the banana man thanks to his claim that the banana is "the atheist's worst nightmare", as the fruit was obviously intelligently designed for human consumption.
If you think I'm joking, check out the video above.
In reality, bananas were selectively bred over time by humans to attain their current "intelligently designed" form. Wild bananas contained large seeds, were not "made to sit comfortably in the human hand", nor did they have the "pointed tip for ease of entry".
As for the creationist Origin, I see no need to seriously worry about it. The arguments in Comfort's introduction are so outdated, wrong and at times downright bizarre that anyone with a half a brain will realize immediately that it is bogus; meanwhile, Darwin's well-reasoned, evidence-based text that follows shines with added brilliance by comparison.
The gist of Comfort's introduction is that if you accept evolution, you will burn in Hell for eternity.
"Perhaps the thought of Hell doesn't scare you, because you don't believe in it," Comfort writes. "That's like standing in the open door of a plane 10,000 feet off the ground and saying, 'I don't believe there will be any consequences if I jump without a parachute'." (Need I point out the logical flaw here?)
Comfort's various criticisms of Darwin's "racism", the implications of "social Darwinism", the "lack of transitional fossils" or evolution's violation of the second law of thermodynamics (which demonstrates a blatant ignorance of physics, as well as biology) are laughable. But in case anyone needs to find out why they are seriously wrong, the always-clever folks at the National Center for Science Education have set up a website in response to Comfort's claims:
"The past of human evolution is more and more coming to light as scientists uncover a trove of fossils and genetic knowledge. But where might the future of human evolution go?
An old cliché has the highly evolved humans of the future sporting large heads to hold their advanced enlarged brains, "but that's nonsense, whole nonsense," said paleontologist Peter Ward at the University of Washington at Seattle, author of "Future Evolution."
"If you've ever gone through a childbirth or witnessed one," Ward says, "we're already anatomically right on the edge of how big our heads can go — our big brains have already caused extreme problems in childbirth, and if we had bigger and bigger brains, that'd cause more mothers to die in childbirth, so evolution would select against that."
Another idea, suggested by evolutionary theorist Oliver Curry of the London School of Economics, seems like a retread of ideas from science fiction writer H.G. Well's classic "The Time Machine," with the human species split in two over time — an underclass of dim-witted, short goblins, and a genetic upper class of tall, slim, healthy, attractive, intelligent and creative superhumans that eventually are spoiled by technology that will do everything for them, resembling domesticated animals.
"That's crap," Ward said. "Why would that happen? Are we like blind cavefish? After we get Google, do we get stupider? Intelligence is coded on too many genes to just lose a trait like intelligence. That's not going to happen."
Ward suggests that, if left untouched, humans might converge in appearance as populations mix. "I kind of view us all as eventually having chocolate-covered hair and medium stature, getting rid of all extremes," he speculated. "Of course, the big elephant in the room, the change from the past that you cannot ignore when talking about the future of human evolution, is genetic engineering."
Humanity now has an unparalleled means by which to direct our evolution — genetic engineering. By using viruses and other techniques, we can in theory modify our genomes, and over time, scientists may uncover genes underlying intelligence, health, athletic prowess, longevity and other desirable traits, engineering what might seem like superhuman progeny. Genetic engineering is how Ward speculated new species of humans might emerge.
"I think taboos would arise which would prevent mating between populations — 'I don't want them anymore' or 'We want natural people,'" he said. "Of course this is all pure speculation, but this is the only way I can see new human species emerging — unless we get off the planet."
So much to think about...where do you think evolution will go? What does the future hold for humans?"The past of human evolution is more and more coming to light as scientists uncover a... more
First, a conspiracy about dollar coins. Now a conspiracy about monkeys and fish.
Former Alaska Gov. Sarah Palin, Sen. John McCain's (R-AZ) vice presidential running mate, signals in her new book Going Rogue that she doesn't believe in evolution, panning it as theory that human beings "originated from fish that sprouted legs and crawled out of the sea."First, a conspiracy about dollar coins. Now a conspiracy about monkeys and fish.... more
Research is pointing to a new perspective on religion, one that seeks to explain why religious behavior has occurred in societies at every stage of development and in every region of the world. Religion has the hallmarks of an evolved behavior, meaning that it exists because it was favored by natural selection. It is universal because it was wired into our neural circuitry before the ancestral human population dispersed from its African homeland.
The evolutionary perspective on religion does not necessarily threaten the central position of either side. That religious behavior was favored by natural selection neither proves nor disproves the existence of gods.
Chimps, our nearest relative, don't talk. We do. Now scientists have pinpointed a mutation in a gene that might help explain the difference.
The mutation seems to have helped humans develop speech and language. It's probably not the only gene involved, but researchers found the gene looks and acts differently in chimps and humans, according to a study published online Wednesday by the journal Nature.
News from The Associated Press http://bit.ly/4zkjrOChimps, our nearest relative, don't talk. We do. Now scientists have pinpointed a... more
Our take on the week: As a UK adviser is fired over politically unpalatable advice, and an English teacher is suspended over an article about animal sexuality, the fate of facts is on the line.
"The discovery of an early human fossil in southern China may challenge the commonly held idea that modern humans originated out of Africa.
Jin Changzhu and colleagues of the Institute of Vertebrate Paleontology and Paleoanthropology in Beijing, announced to Chinese media last week that they have uncovered a 110,000 year old putative Homo sapiens mandible from a cave in southern China's Guangxi province.
The mandible has a protruding chin like that of Homo sapiens, but the thickness of the jaw is indicative of more primitive hominins, suggesting that the fossil could derive from interbreeding.
If confirmed, the finding would lend support to the"multiregional hypothesis". This says that modern humans descend from Homo sapiens coming out of Africa who then interbred with more primitive humans on other continents. In contrast, the prevailing "Out of Africa" hypothesis holds that modern humans are the direct descendents of people who spread out of Africa to other continents around 100,000 years ago.
The study will appear in Chinese Science Bulletin later this month.""The discovery of an early human fossil in southern China may challenge the commonly... more
Does running a marathon push the body further than it is meant to go?
The conventional wisdom is that distance running leads to debilitating wear and tear, especially on the joints. But that hasn’t stopped runners from flocking to starting lines in record numbers.
Last year in the United States, 425,000 marathoners crossed the finish line, an increase of 20 percent from the beginning of the decade, Running USA says. Next week about 40,000 people will take part in the New York City Marathon. Injury rates have also climbed, with some studies reporting that 90 percent of those who train for the 26.2-mile race sustain injuries in the process.
But now a best-selling book has reframed the debate about the wisdom of distance running. In “Born to Run” (Knopf), Christopher McDougall, an avid runner who had been vexed by injuries, explores the world of the Tarahumara Indians of Mexico, a tribe known for running extraordinary distances in nothing but thin-soled sandals.
Mr. McDougall makes the case that running isn’t inherently risky. Instead, he argues that the commercialization of urban marathons encourages overzealous training, while the promotion of high-tech shoes has led to poor running form and a rash of injuries.
Though Charles Darwin thought of religion as a tribal survival strategy, in 1879 he wrote that "I think that generally ... an agnostic would be the most correct description of my state of mind.” When he published The Origin of Species 150 years ago, he deliberately avoided the subject of the origin of life. This, coupled with the mention of the 'Creator' in the last paragraph of the book, led many to believe he was not willing to commit on the matter.
Now, an international team, led by Juli Peretó of the Cavanilles Institute in Valencia, refutes that idea and shows that the British naturalist did explain in other documents how our first ancestors could have come into being.
"All organic beings that have lived on Earth could be descended from some primordial form", explained Darwin in The Origin of Species in 1859. Despite this statement, the scientist took it upon himself to understand the evolutional processes underlying biodiversity.
"Darwin was convinced of the incredible importance of this issue for his theory and he had an amazingly modern materialist and evolutional vision about the transition of inanimate chemical matter into living matter, despite being very aware of Pasteur's experiments in opposition to spontaneous generation", Juli Peretó, principal author of this study and researcher at the Cavanilles Institute of Evolutional Biology and Biodiversity at the University of Valencia, explains to SINC.
The study, which is published in the latest issue of the journal Origins of Life and Evolution of Biospheres, demonstrates that Darwin had an advanced idea on the origin of the first species, and was troubled by the problem. "It is utterly wrong to think that he was invoking a divine intervention; it is also well documented that the mention of the 'Creator' in The Origin of the Species was an addition for appearance's sake that he later regretted", affirms Peretó.
According to the researchers, all Darwin's opinions on the origin of life can be found in his private correspondence and in his notebooks. The exception is a review of a book on foraminiferous microorganisms published in 1863 in the London social club Athenaeum, where Darwin "lets his opinion on the spontaneous generation be known".
The international team, comprising Spanish, US and Mexican scientists, has not only examined in detail the phrases, texts and paragraphs of the letters, but has also put into context all Darwin's opinions on the origins of life, available online and in the original manuscripts.
A comment in a notebook dating back to 1837, in which Darwin explains that "the intimate relationship between the vital phenomena with chemistry and its laws makes the idea of spontaneous generation conceivable", gave the researchers their clue.
In another famous letter sent in 1871 to his friend, the English botanist and explorer Joseph D. Hooker, Charles Darwin imagines a small, warm pool where the inanimate matter would arrange itself into evolutionary matter, aided by chemical components and sufficient sources of energy.
In other letters, the naturalist admitted to colleagues such as Alfred Russel Wallace or Ernst Haeckel that spontaneous generation was important to the coherence of the theory. However, "at the same time, he acknowledged that science was not advanced enough to deal with the question (hence his reluctance to speak of it in public) and that he would not live to see it resolved", Peretó points out.Though Charles Darwin thought of religion as a tribal survival strategy, in 1879 he... more
Unfortunately, it has been discovered that Ida has no known descendants.
"It was billed as one of the most important fossil finds in history, a “missing link” that would challenge everything we knew about human evolution.
Darwinius masillae, the primitive primate that was unveiled to the world with huge fanfare and a Sir David Attenborough documentary in May, seems now to have been less of a missing link than an evolutionary dead end.
Far from being an ancestor to humans, the lemur-like creature from 47 million years ago belongs to an entirely different branch of the primate family tree that has left no known descendants, research has indicated.
When Jørn Hurum, of the University of Oslo Natural History Museum, announced the discovery of the astonishingly well-preserved fossil, he described it as “the first link to all humans.”Unfortunately, it has been discovered that Ida has no known descendants.
"It was... more
Emory University researchers have identified the first fish known to have switched from ultraviolet vision to violet vision, or the ability to see blue light. The discovery is also the first example of an animal deleting a molecule to change its visual spectrum.
Their findings on scabbardfish, linking molecular evolution to functional changes and the possible environmental factors driving them, were published Oct. 13 in the Proceedings of the National Academy of Sciences.
"This multi-dimensional approach strengthens the case for the importance of adaptive evolution," says evolutionary geneticist Shozo Yokoyama, who led the study. "Building on this framework will take studies of natural selection to the next level."
The research team included Takashi Tada, a post-doctoral fellow in biology, and Ahmet Altun, a post-doctoral fellow in biology and computational chemistry.
Vision 'like a painting'
For two decades, Yokoyama has done groundbreaking work on the adaptive evolution of vision in vertebrates. Vision serves as a good study model, since it is the simplest of the sensory systems. For example, only four genes are involved in human vision.
"It's amazing, but you can mix together this small number of genes and detect a whole color spectrum," Yokoyama says. "It's just like a painting."
The common vertebrate ancestor possessed UV vision. However, many species, including humans, have switched from UV to violet vision, or the ability to sense the blue color spectrum.
From the ocean depths
Fish provide clues for how environmental factors can lead to such vision changes, since the available light at various ocean depths is well quantified. All fish previously studied have retained UV vision, but the Emory researchers found that the scabbardfish has not. To tease out the molecular basis for this difference, they used genetic engineering, quantum chemistry and theoretical computation to compare vision proteins and pigments from scabbardfish and another species, lampfish. The results indicated that scabbardfish shifted from UV to violet vision by deleting the molecule at site 86 in the chain of amino acids in the opsin protein.
"Normally, amino acid changes cause small structure changes, but in this case, a critical amino acid was deleted," Yokoyama says.
More examples likely
"The finding implies that we can find more examples of a similar switch to violet vision in different fish lineages," he adds. "Comparing violet and UV pigments in fish living in different habitats will open an unprecedented opportunity to clarify the molecular basis of phenotypic adaptations, along with the genetics of UV and violet vision."
Scabbardfish spend much of their life at depths of 25 to 100 meters, where UV light is less intense than violet light, which could explain why they made the vision shift, Yokoyama theorizes. Lampfish also spend much of their time in deep water. But they may have retained UV vision because they feed near the surface at twilight on tiny, translucent crustaceans that are easier to see in UV light.
A framework for evolutionary biology
Last year, Yokoyama and collaborators completed a comprehensive project to track changes in the dim-light vision protein opsin in nine fish species, chameleons, dolphins and elephants, as the animals spread into new environments and diversified over time. The researchers found that adaptive changes occur by a small number of amino acid substitutions, but most substitutions do not lead to functional changes.
"Evolutionary biology is filled with arguments that are misleading, at best," Yokoyama says. "To make a strong case for the mechanisms of natural selection, you have to connect changes in specific molecules with changes in phenotypes, and then you have to connect these changes to the living environment."Emory University researchers have identified the first fish known to have switched... more
It's been a rather big year for Charles Darwin. 2009 is the bicentennial of the man's birth and the 150th anniversary of the publication of "The Origin of Species," and the explorer and naturalist has been the subject of books (including a graphic novel adaptation of "The Origin of Species"), a movie starring Jennifer Connelly (with its own ensuing controversy), and even a viral video hit starring "Growing Pains" actor Kirk Cameron. Given that evolutionary biology is Richard Dawkins' area of expertise, it's unsurprising that the British scientist, atheist and controversial author of "The God Delusion" has also gotten on the bandwagon -- in rather ambitious fashion.
In "The Greatest Show on Earth," Dawkins has written what is essentially a layperson's primer for the theory of evolution. Dawkins aims to explain to the everyday reader why evolution isn't a "theory" but a fact and that we need only look around us to find evidence of its existence -- from continental drift to the reproductive habits of wasps. Dawkins uses simple language, elaborate metaphors and color photographs to make his point, and the result is a convincing, if occasionally dry, overview of evolutionary biology. It's also clear, from the book's first pages, that Dawkins isn't very tolerant of his creationist opponents (the book includes a memorably confrontational encounter with Wendy Wright, the creationist president of Concerned Women for America).
Salon spoke with Dawkins via Skype about creationism's popularity in America, its connection with religion, and how he feels about his own notoriety. A video excerpt of the conversation is posted below.
...................................
(excerpt)
Q: Do you think that there's any one particular piece of evidence that will change people's minds about creationism, or do you think that it's really just a question of a gradual erosion of people's belief systems?
A: I wouldn't expect their minds to be changed by fossils, really. I think the more convincing evidence is the evidence from comparison of modern animals and plants, because we have so many different species, and by comparing them with each other, particularly comparing the molecular genetics which is nowadays very easily done. All living creatures have the same genetic code, so you have an exact digital count of the similarities between every species and every other species, and if you look at that pattern of similarities it falls perfectly into a hierarchical tree. It's a family tree. And even better than that, everything you look at -- every different gene you look at -- gives you the same family tree. That's remarkably persuasive evidence to anybody who attends to it long enough to understand.It's been a rather big year for Charles Darwin. 2009 is the bicentennial of the man's... more
WASHINGTON — The Smithsonian's National Museum of Natural History plans to open a hall next year dedicated to the story of human evolution over 6 million years, officials announced Wednesday.WASHINGTON — The Smithsonian's National Museum of Natural History plans to open a... more
LONDON (Reuters) - Many prehistoric Australian aboriginals could have outrun world 100 and 200 meters record holder Usain Bolt in modern conditions.
Some Tutsi men in Rwanda exceeded the current world high jump record of 2.45 meters during initiation ceremonies in which they had to jump at least their own height to progress to manhood.
Any Neanderthal woman could have beaten former bodybuilder and current California governor Arnold Schwarzenegger in an arm wrestle.
These and other eye-catching claims are detailed in a book by Australian anthropologist Peter McAllister entitled "Manthropology" and provocatively sub-titled "The Science of the Inadequate Modern Male."
McAllister sets out his stall in the opening sentence of the prologue.
"If you're reading this then you -- or the male you have bought it for -- are the worst man in history.
"No ifs, no buts -- the worst man, period...As a class we are in fact the sorriest cohort of masculine Homo sapiens to ever walk the planet."LONDON (Reuters) - Many prehistoric Australian aboriginals could have outrun world 100... more
Meet the latest pterosaur - winged prehistoric reptile. Darwinopterus or Darwin's Wing is from China circa the Jurassic age. Another example of just how far Charles Darwin was ahead of his time.Meet the latest pterosaur - winged prehistoric reptile. Darwinopterus or Darwin's Wing... more
“All that is Solid Melts into the Air” is a fascinating 1-minute short film that was directed, designed and animated by Marco Vinicio Morales. Morales describes the film as a visual and poetic journey influenced by art, design, architecture and photography. It illustrates the process whereby under the violent irruption of forms and structures, everything flows towards a constant evolution.
This piece includes a number of b&w photographs from the film, as well as the very intriguing short film, “All that is Solid Melts into the Air.”“All that is Solid Melts into the Air” is a fascinating 1-minute short film that... more
