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A team of Princeton University scientists has discovered that chains of proteins found in most living organisms act like adaptive machines, possessing the ability to control their own evolution.
The research, which appears to offer evidence of a hidden mechanism guiding the way biological organisms respond to the forces of natural selection, provides a new perspective on evolution, the scientists said.
The researchers -- Raj Chakrabarti, Herschel Rabitz, Stacey Springs and George McLendon -- made the discovery while carrying out experiments on proteins constituting the electron transport chain (ETC), a biochemical network essential for metabolism. A mathematical analysis of the experiments showed that the proteins themselves acted to correct any imbalance imposed on them through artificial mutations and restored the chain to working order.
"The discovery answers an age-old question that has puzzled biologists since the time of Darwin: How can organisms be so exquisitely complex, if evolution is completely random, operating like a ''''blind watchmaker''''?" said Chakrabarti, an associate research scholar in the Department of Chemistry at Princeton. "Our new theory extends Darwin''''s model, demonstrating how organisms can subtly direct aspects of their own evolution to create order out of randomness." -Article with links, continued Off Site, courtesy News At Princeton.
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Posted by Shinai_Gene on Thursday, November 13, 2008 @ 00:10:00 PST (178 reads)
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Some students burst into tears when a high school biology told them they’d be studying evolution. Another teacher said some students repeatedly screamed “no” when he began talking about it.
Other teachers said students demanded to know whether they pray and questioned why the had to learn about evolution if it was just a theory.
About 60 public high school teachers from the Atlanta area were at Emory University last week, swapping stories about the challenges they face when teaching evolution.
They said students often walk in with grave misconceptions about the subject, and many parents fear teachers will tell kids that they can’t have their religious beliefs.
“I’ve seen churches train students to come to school with specific questions to ask to sabotage my lessons,” said Bonnie Pratt, a biology teacher at Northview High in north Fulton County. “We need parents and the community to understand why and how we teach evolution.”
The teachers were at a workshop on teaching evolution organized by Emory’s Center for Science Education. They discussed ways to teach it and how to address challenges and misconceptions. The training was part of a two-day evolution conference on campus that ended Friday.
Evolution is the scientific explanation for the gradual process that resulted in the diversity of living things. -Article Continues Off Site, courtesy The Atlanta Journal-Constitution.
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Christian creationists have long railed against the theory of evolution. But you may not have heard anything yet.
A new Canadian paper in the journal Science suggests that Christianity itself may be a function of evolution.
In a review article that is sure to prove controversial, University of British Columbia researchers say that the world''''s great religions may have emerged as a codification of cultural traits that allowed people to be more successful breeders.
"We're setting aside the question of whether religions are true in a metaphysical sense," says Ara Norenzayan, a UBC psychologist and lead author of the paper. He and his team reviewed dozens of studies on the emergence of religions from disciplines as diverse as psychology, history, sociology, anthropology, economics and ethnography.
"We're trying to understand what religion is and explain it in terms of human nature and human culture."
The paper argues that social co-operation and altruism conferred an evolutionary advantage as populations grew larger, and that moralizing religions were key to creating large-scale cohesion. -Article continues Off Site. Courtesy: The Toronto Star.
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Posted by Shinai_Gene on Sunday, October 05, 2008 @ 03:15:00 PDT (1295 reads)
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The Church of England will tomorrow officially apologise to Charles Darwin for misunderstanding his theory of evolution.
In a bizarre step, the Church will address its contrition directly to the Victorian scientist himself, even though he died 126 years ago.
But the move was greeted with derision last night, with Darwin’s great-great-grandson dismissing it as ‘pointless’ and other critics branding it ‘ludicrous’.
Church officials compared the apology to the late Pope John Paul II’s decision to say sorry for the Vatican’s 1633 trial of Galileo, the astronomer who appalled prelates by declaring that the earth revolved around the sun.
The officials said that senior bishops wanted to atone for the vilification their predecessors heaped on Darwin in the 1860s, when he put forward his theory that man was descended from apes.
The Church is also anxious to counter the view that its teaching is incompatible with science. It wants to distance itself from fundamentalist Christians, who believe in the Biblical account of the creation of the world in seven days.
Article Continues (Off Site)
Courtesy: The Daily Mail. (UK)
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Darwin never warned against crossing black cats, walking under ladders or stepping on cracks in the pavement, but his theory of natural selection explains why people believe in such nonsense.
The tendency to falsely link cause to effect – a superstition – is occasionally beneficial, says Kevin Foster, an evolutionary biologist at Harvard University.
For instance, a prehistoric human might associate rustling grass with the approach of a predator and hide. Most of the time, the wind will have caused the sound, but "if a group of lions is coming there’s a huge benefit to not being around," Foster says.
Foster and colleague Hanna Kokko, of the University of Helsinki, Finland, sought to determine exactly when such potentially false connections pay off.
Simplified behaviour
Article Continues ( Off Site)
Courtesy New Scientist.
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Posted by Shinai_Gene on Friday, September 12, 2008 @ 05:40:40 PDT (1812 reads)
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Strands of DNA recovered from the fossilised leg bone of a Neanderthal have shed light on the fragility of this ancient hominid species and pinpointed when they first split from what were to become modern humans.
The 38 000-year-old bone was unearthed in a cave in Vindija in Croatia and has become part of a landmark project to read the entire genetic sequence of Neanderthals, a feat scientists believe will help reveal how modern humans evolved into the world's dominant species.
Researchers at the Max-Planck Institute for Evolutionary Anthropology in Leipzig, Germany, read the complete DNA sequence held in tiny biological powerhouses called mitochondria, which provide energy for cells. The mitochondria are only passed down the female line, so can be used to trace the species back to an ancestral "Eve", the mother of all Neanderthals.
The team analysed the DNA of 13 genes from the Neanderthal mitochondria and found they were distinctly different to modern humans, suggesting Neanderthals never, or rarely, interbred with early humans. The genetic material shows that a Neanderthal "Eve" lived around 660 000 years ago, when the species last shared a common ancestor with humans.
Further tests on the DNA revealed surprisingly few evolutionary changes, suggesting that the Neanderthals may only ever have existed in relatively small numbers with less than 10 000 alive at any one time.
Article Continues ( Off Site)
Courtesy The Mail & Guardian
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Posted by Shinai_Gene on Thursday, August 21, 2008 @ 23:37:30 PDT (2701 reads)
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After two tremendous growth spurts — one in size, followed by an even more important one in cognitive ability — the human brain is now a lot like a teenage boy.
It consumes huge amounts of calories, is rather temperamental and, when harnessed just right, exhibits incredible prowess. The brain's roaring metabolism, possibly stimulated by early man's invention of cooking, may be the main factor behind our most critical cognitive leap, new research suggests.
About 2 million years ago, the human brain rapidly increased its mass until it was double the size of other primate brains.
"This happened because we started to eat better food, like eating more meat," said researcher Philipp Khaitovich of the Partner Institute for Computational Biology in Shanghai.
But the increase in size, Khaitovich continued, "did not make humans as smart as they are today."
The early shift
Article Continues ( Off Site)
Courtesy Live Science
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Posted by Shinai_Gene on Tuesday, August 12, 2008 @ 13:31:14 PDT (2773 reads)
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Aug. 7, 2008 -- DNA extracted from a 38,000-year-old Neanderthal bone has just enabled scientists to sequence the complete mitochondrial genome for the human-like species, according to a paper that will be published tomorrow in the journal Cell.
The remarkable feat, which has led to at least three major discoveries about the extinct stocky European individuals, represents a breakthrough for studies on the human family.
"This is the first complete mitochondrial genome sequence from an extinct hominid," lead author Richard Green explained to Discovery News.
Mitochondria, which an individual inherits from his or her mother, are cellular powerhouses that possess their own DNA and include 13 protein-coding genes. The researchers sequenced the Neanderthal mitochondria 35 times to ensure their findings were as accurate as possible.
After studying the newly completed genome, Green, a researcher at the Max-Planck Institute for Evolutionary Anthropology in Germany, and his team first concluded that the Neanderthal mitochondria falls outside the range of variation found in humans today, offering no evidence that interbreeding occurred between them and us.
Article Continues (Off Site)
Courtesy Discovery News
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Posted by Shinai_Gene on Thursday, August 07, 2008 @ 15:58:49 PDT (2379 reads)
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If you judge the progress of humanity by Homer Simpson, Paris Hilton, and Girls Gone Wild videos, you might conclude that our evolution has stalled—or even shifted into reverse. Not so, scientists say. Humans are evolving faster than ever before, picking up new genetic traits and talents that may help us survive a turbulent future.
Much remodeling has gone on since the dawn of agriculture about 10 millenniums ago. "People who lived 10,000 years ago were much more like Neanderthals than we are like those people," says John Hawks, a professor of anthropology at the University of Wisconsin. "We've changed."
Hawks is among a growing number of scientists who are using whole-genome sequencing and other modern technologies to zero in on just how we've changed. Their research is helping illuminate not only how humans became what we are but also where we might be headed. For instance, some scientists speculate that changes in human mating patterns may be contributing to the increase in autism. Others track how humans have morphed in response to changing circumstances, including enhanced abilities to metabolize sugar and fight disease. Some people are genetically more resistant to the HIV virus, for instance, and that trait should become more common in the future, as those people are more likely to survive and have children who are resistant. Yet for some people, the makeover isn't big enough or fast enough. Some parents have started using DNA testing to choose the genetic makeup of their children, rejecting embryos with inherited flaws or embracing those with desired traits—such as being the right sex.
Article Continues ( Off Site)
Courtesy: USNews
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