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POPSThe DNA Mystery: Scientists Stumped By "Telepathic" Abilities Even so, research published in ACS’ Journal of Physical Chemistry B, shows very clearly that homology recognition between sequences of several hundred nucleotides occurs without physical contact or presence of proteins. Double helixes of DNA can recognize matching molecules from a distance and then gather together, all seemingly without help from any other molecules or chemical signals. This recognition effect may help increase the accuracy and efficiency of the homologous recombination of genes, which is a process responsible for DNA repair, evolution, and genetic diversity. The new findings may also shed light on ways to avoid recombination errors, which are factors in cancer, aging, and other health issues.
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POPSChemists edge closer to recreating early life Joyce's experiment was designed to test the 'RNA World' theory, which proposes that DNA-based life evolved from a stage whereby RNA acted as both an information-storage molecule, like DNA, and as a catalyst, like enzymes, and was also capable of self-replication. This work is the biggest injection of support for the RNA world hypothesis in a long time,' says Donna Blackmond, Chair in Catalysis at Imperial College London, UK. 'It's a demonstration of principle that indefinite replication, coupled with selection via mutation, is quite plausible for RNA. The fact that it goes on indefinitely is a big thing for showing that this really could have been how life started,' she adds.
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POPSEarth's Original Ancestor Was 'LUCA' The research team compared genetic information from modern organisms to characterize the ancient ancestor of all life on earth. "Our research is much like studying the etymology of modern languages so as to reveal fundamental things about their evolution," says professor Lartillot. "We identified common genetic traits between animals, plant, bacteria, and used them to create a tree of life with branches representing separate species. These all stemmed from the same trunk – LUCA, the genetic makeup that we then further characterized." The group's findings are an important step towards reconciling conflicting ideas about LUCA. In particular, they are much more compatible with the theory of an early RNA world, where early life on Earth was composed of ribonucleic acid (RNA), rather than deoxyribonucleic acid (DNA).
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POPS'Junk' DNA proves functional Over evolutionary time, these repeats were dispersed within different species, creating new regulatory sites throughout these genomes. Thus, the set of genes controlled by these transcription factors is likely to significantly differ from species to species and may be a major driver for evolution. This research also shows that these repeats are anything but "junk DNA," since they provide a great source of evolutionary variability and might hold the key to some of the important physical differences that distinguish humans from all other species. The GIS study also highlighted the functional importance of portions of the genome that are rich in repetitive sequences.
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POPSMapping the Bio Cosmos Microbes are responsible for many biogeochemical cycles and are crucial to the continued function of the , Woese's efforts to clarify the evolution and diversity of microbes provided an invaluable service to ecologists and conservationists. Woese’s big idea is that primitive life existed as a community of cells that freely exchanged genes. They shared a basic translation system for making proteins, but had little else in common. These cells evolved as a community and not as distinct lineages. Before Woese, the tree of life had two main branches called prokaryotes and eukaryotes, the prokaryotes composed of cells without nuclei and the eukaryotes composed of cells with nuclei.
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POPSVideo of the First 24 Hours of an Embryo's Cells The new technique, called Digital Scanned Laser Light-Sheet Fluorescence Microscopy, could be used on other animals such as mice, chicken and frogs, which would could help researchers better understand evolution at the cellular scale. Already, the research has shown that the initial stages of heart development do not happen as scientists thought.
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POPSWill the Internet Evolve into a Lifeform? One route is the evolution of electronic intelligences in situations like the internet-arms race between spammers and shielders. It might sound silly, the idea that new life could be created in an attempt to offer you a great deal on C1@Lis!!, but have you tried registering for a forum recently? Even gaining access to the lowest level of interaction online now requires elementary Turing tests to tell the humans from the robots. Another option is the idea of the net itself becoming sentient, a vast self-modifying array of connections and information storage with limited connections to the outside world (kind of like that glob of grey goo you carry around in your skull). If that happens then Gibson help us all - remember that the net is made of about 90% spam, 9% porn, and quite a lot of whining blogs. If that mixture ever becomes self-aware we're not quite sure what it'll do, but the odds are against it being anything good.
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POPSEvolution in a Bottle Over time the bacteria evolved to better suit their environment, adapting to replicate faster on the all-glucose diet. But one colony suddenly took off, consuming the previously indigestible citrate - a molecule that literally would not fit through the original bacteria's membrane. A new breed of E. Coli had evolved to consume the available resources and, over a multi-generational evolutionary battle, came to outperform the original glucose eaters. Because of the daily samples, there is now a complete genetic paper trail of the changes (although full identification and understanding of the changes will take a little longer). This is an incredible breakthrough in evolutionary research, and a pretty nice argument to break out in the creationism 'debates' ("Prove evolution!" "Okay, I've got it right here IN THIS BOTTLE!")
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POPSArsenic-eating bacteria rewrite evolutionary history Oremland's team isolated and bred these bacteria in the lab. By growing them with with arsenite as the only possible food source, the researchers showed that the bacteria can indeed thrive. The results suggest that arsenic photosynthesis evolved at the same time, or even before, "normal" photosynthesis. Oremland says a similar mechanism might once have fuelled life on Mars or on Jupiter's moon Europa.
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POPSWere Ancient Viruses a Key to Human Evolution? These viral fragments are fossils that reside within each of us, carrying a record that goes back millions of years. Because they no longer seem to serve a purpose or cause harm, these remnants have often been referred to as “junk DNA.” Although many of these evolutionary relics still manage to generate proteins, scientists have never found one that functions properly in humans or that could make us sick. That is until Thierry Heidmann who runs the laboratory at the Institut Gustave Roussy, on the southern edge of Paris, brought one to life. Heidmann long suspected that if a retrovirus happens to infect a human sperm cell or egg, which is rare, and if that embryo survives—which is rarer still—the retrovirus could have the evolutionary power to influence humans as a species becoming part of the genetic blueprint, passed from mother to child, and from one generation to the next, much like a gene for eye color or asthma.
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POPSDinosaur evolutionary tree unveiled It remained at that low level throughout the following Cretaceous period, a time of plenty in Earth's terrestrial history in which flowering plants, lizards, snakes, birds and mammals all became much more numerous. Dinosaurs apparently did not take advantage of the abundant food supply that emerged during the Cretaceous Terrestrial Revolution. "Our supertree allows us to look for unusual patterns across the whole of dinosaurs for the first time," says Lloyd. "It is the most comprehensive picture ever produced of how dinosaurs evolved."
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POPSFlatfish caught evolving, thanks to its roving eye Now Friedman reports finding two different missing links. They are fossil fish with their eyes in different places on the two sides of their skulls - one in the normal position and one closer to the midline (see Diagram). One is Amphistium, a previously described genus found in several fossil deposits in Europe, in which the asymmetry went unnoticed because in fish fossils only one side of the animal is generally preserve. The other is Heteronectes, a new genus. At 10 to 20 centimetres long, the specimens were clearly adults and not larvae in which the eyes were migrating
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POPSWill Our Future Brains Be Smaller? Why does the brain need these two decision-making areas? What benefit does the new cortex bring? After all, extra brain means extra weight and energy required to carry it around. Furthermore, is the older sub-cortical system now largely redundant? If so, could we expect it to atrophy in future humans so our brains become smaller? The results of their modelling showed that when the threat level is high, such as the risk of being attacked by a dangerous animal, it is very useful to have the fast-acting, if inaccurate, system. But when dealing with situations which don't occur very often, or complex scenarios with many conflicting cues such as social situations, the cortical system is of more use than the sub-cortical system.
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POPSUnintelligent Design At this point, 30 years after the Nobel Laureate Daniel Kahneman and his late collaborator Amos Tversky started documenting a rash of fallacies in human reasoning, the idea that the human mind would be "perfect in His image" is as outdated (and narcissistic) as the idea that the solar system would revolve around the planet earth. The only theory that can really make sense of these needless imperfections is Darwin's theory of natural selection, which holds that humans (and all other life forms) evolve through a blind process known as descent-with-modification, in which new life forms represent random modifications of earlier life forms -- with no central overseer to guide the process. Such a random process can, over time, lead populations of creatures to become more adapted to their environment, but it is also vulnerable to getting stuck, in the sort of good-enough-but-not-perfect solutions that mathematicians call local maxima.
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POPSMechanism and function of humor identified by new evolutionary theory "By removing stipulations of content we have been forced to study the structures underlying any instance of humour, and it has become clear that it is not the content of the stimulus but the patterns underlying it that provide the potential for sources of humour. For patterns to exist it is necessary to have some form of content, but once that content exists, it is the level of the pattern at which humour operates and for which it delivers its rewards." Previous theories have only ever applied to a small proportion of all instances of humour, many of them stipulating necessary content or social conditions either in the humour itself or around the individual experiencing it. But this doesn't explain why an individual can laugh at something when no one else around them does, nor why two people can laugh at the same stimulus for different reasons.
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POPSThe ADHD Advantage: Did the “Hyper” Gene Benefit Our Nomadic Ancestors? "So, in other words, all of us with ADHD need to head back to the desert with a pack of camels loaded up with tents to really make the most of our “disorder” (how dare they call it that when it turns out it’s an evolutionary advantage unless you’re a semi-comatose couch potatoes). Of course half of us will absent-mindedly forget to bring essentials—like water—but we’ll have a lot of fun. Who’s with me?"
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POPSCan parasites influence the language we speak? "These costly interactions especially come from interacting with people who do not belong to your society or group, whose immune systems are adapted for a separate set of parasites than your own," adds Fincher. n the parasite-rich forest populations, interacting with others came with a high chance of contracting a lethal illness, making parasites an evolutionary driving force.
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POPSReligion is a product of evolution, software suggests Another contends that religion benefited our ancestors. Rather than being a by-product of other brain functions, it is an adaptation in its own right. In this explanation, natural selection slowly purged human populations of the non-religious. To determine if it was possible for religion to emerge as an adaptation, Dow wrote a simple computer program that focuses on the evolutionary benefits people receive from their interactions with one another.
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POPSEvolution: 24 myths and misconceptions So here is New Scientist's guide to some of the most common myths and misconceptions about evolution.Everything is an adaptation produced by natural selection Natural selection is the only means of evolution Natural selection leads to ever-greater complexity Evolution produces creatures perfectly adapted to their environment Evolution always promotes the survival of species It doesn't matter if people do not understand evolution "Survival of the fittest" justifies "everyone for themselves" Evolution is limitlessly creative Evolution cannot explain traits such as homosexuality Creationism provides a coherent alternative to evolution
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POPS'Babelfish' to translate alien tongues could be built But Deacon argues that all languages arise from the common goal of describing the physical world. That limits the way a language could be constructed, he concludes. An alien race could use a strange medium like scents as their language, Deacon says, but the scents would still describe objects in their world. An odour that communicates "rock" or "tree" would be analogous to our words for the same objects. So there must be an underlying universal code that can be deciphered, as in mathematics.
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POPSA Speech Center of the Monkey Brain Has Been Found! The researchers played recorded coos, grunts, and other vocalizations made by macaques, but also other animals and natural sounds like thunder and running water. A small area of the macaques' temporal lobes turned on only in response to macaque voices, being insensitive to other sounds. The nucleus could differentiate the voices of individual macaques: its activity decreased when the researchers played several times a monkey's voice, but it was boosted by a new played voice.
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POPSSchizophrenia: The Curse That's Almost a Blessing
A recent study may have found what kind of process goes awry in schizophrenic brains. Researchers found that DISC1 regulates the migration of new neurons in the adult brain. When the levels of DISC1 were reduced in mice during adult neurogenesis, the newborn neurons sped up and overshot their intended targets within the hippocampus, When the neurons finally reached their destinations, they forged an unusual number of connections with neighboring cells, a series of events that might give rise to the abnormal—and quite crippling—brain functions associated with schizophrenia, according to Hongjun Song, a Johns Hopkins neurologist who also worked on the study. It is possible, Song says, that further research will lead to a drug that treats schizophrenia by restoring normal neurogenesis. So what evolutionary advantage could schizophrenia-related genes bring to people who have some of the genes but not the disease? For now, this remains one of the many open questions.
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