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Before DNA, before RNA: Life in the hodge-podge world - life - 08 January 2012

Before DNA, before RNA: Life in the hodge-podge world - life - 08 January 2012
Take note, DNA and RNA: it's not all about you. Life on Earth may have begun with a splash of TNA – a different kind of genetic material altogether. Because RNA can do many things at once, those studying the origins of life have long thought that it was the first genetic material. But the discovery that a chemical relative called TNA can perform one of RNA's defining functions calls this into question. Today, most life bar some viruses uses DNA to store information, and RNA to execute the instructions encoded by that DNA. A key piece of evidence for this "RNA world" hypothesis is that RNA is a jack of all trades. Now it seems TNA might have been just as capable, although it is not found in nature today. It differs from RNA and DNA in its sugar backbone: TNA uses threose where RNA uses ribose and DNA deoxyribose. Chaput and his colleagues have now created a TNA molecule that folds into a three-dimensional shape and clamps onto a specific protein. No TNA world Cousins of DNA Recommended by

Supersoldier Ants Reveal Evolutionary Secret | Social Insects & Atavisms When eight bizarrely big-headed soldier ants turned up in a wild colony collected from Long Island, N.Y., scientists knew they had found something interesting. This discovery of these oversized versions of soldier ants, whose job is to defend the nest, led researchers to create their own supersoldier ants in the lab with the help of a hormone, and, by doing so, offer an explanation for how ants, and possibly other social insects, take on specific forms with dedicated jobs within their colonies. It turns out these abnormal soldier ants were throwbacks to an ancestral state, one that no longer shows up within their species except, apparently, by accident. "It's been known for a long time that these kinds of slips occur, and they are viewed as the Barnum and Bailey of evolution," said the study's senior researcher Ehab Abouheif, Canada research chair in evolutionary developmental biology at McGill University. Meet the supersoldiers Making a supersoldier So why have supersoldiers?

British scientists recreate the molecules that gave birth to life itself By Nick Enoch Updated: 08:03 GMT, 27 January 2012 Organic chemists at the University of York have recreated a pair of simple sugars - threose and erythrose - in a process which could have occurred before the advent of life Scientists are one step closer to understanding the origin of life after making a breakthrough into how sugar molecules found in DNA are created. Organic chemists at the University of York have recreated a pair of simple sugars - threose and erythrose - in a process which could have occurred before the advent of life. The team, led by Dr Paul Clarke, along with colleagues at the University of Nottingham, have made the first step towards showing how the basic building blocks of life developed. Every biological molecule has an ability to exist in a left-handed form or right-handed form. All sugars in biology are made up of the right-handed form of molecules and yet all the amino acids that make up the peptides and proteins are made up of the left-handed form.

Return of the super ants An entire genus of ants, comprising more than 1,000 species, has been found to have a hidden ability to make 'supersoldiers' — larger-than-average soldier ants that defend the nest against invaders. And all it takes is a dab of hormone. A few ant species of the Pheidole genus were already known to produce supersoldiers that deter invading army ants by blocking nest entrances with their enormous heads. Scientists have only ever seen these supersoldiers in 8 out of 1,100 Pheidole species. Photo courtesy of Alex Wild/alexanderwild.com Soldiers and supersoldiers from the hyper-diverse ant genus Pheidole marching side by side to defend their nest. The eight species that routinely produce supersoldiers are found only in the southwestern United States and in northern Mexico. Abouheif and his colleagues found that the ants’ supersoldier program is an extension of the same developmental events that set normal soldiers apart from workers. But that is not the case.

Dragonflies keeping their eyes on the prize | The Scicurious Brain One of the things I love most about science blogging is the opportunity to learn about entirely new things. Of course, we all have that opportunity on most days, but having to find something to blog about three times a week definitely keeps me on my toes. And what I learn can be so fascinating! Often it’s about barnacle sperm or the evo psych of romance novels, but there are other, safe for work kinds of fascination, too! And today, my fascination is with dragonflies. And my fascination with them grew even more as I read this paper. Gonzalez-Bellido et al. (Source) The authors recorded from the visual neurons of a large number of dragonflies as they were presented with prey moving across the visual field. These dragonflies have a set of neurons called small target movement detectors, which specifically detect the small and speedy movements of potential prey. The visual fields were all partially overlapping, creating an area of very high sensitivity right at the midline. *Kidding!

Telomere length in birds predicts longevity Protective caps known as telomeres that help to preserve the integrity of chromosomes can also predict lifespan in young zebra finches (Taeniopygia guttata), researchers have found. Telomeres are stretches of repetitive DNA sequence that are found at the ends of chromosomes, where they help to maintain cell viability by preventing the fraying of DNA and the fusion of one chromosome to another. The relationship between normal ageing and telomere decline has long been suspected — and even asserted by some companies that measure customers’ telomere length — but the link remains unproven in humans (see 'Spit test offers guide to health'). P. The lifespan of zebra finches is strongly correlated with the length of the chromosome caps that protect their DNA, known as telomeres, particularly at 25 days old. Most studies of longevity and telomere length have relied on only one or two measurements from an individual during their lifespan.

Life Science Reference - Biology Online Resurrecting Evolution to Solve an 800-Million-Year-Old Puzzle | The Loom This is a story of about how the parts of a puzzle locked into place 800 million years ago. The puzzle is an ion pump that you can find in any mushroom, mold, or yeast. I’ve reproduced a picture of it here. Fungus cells, like our own cells, have lots of little pouches inside of them for carrying out special kinds of chemical reactions. In order for those reactions to work, there have to be a lot of positively-charged protons inside the pouches. This pump (which is is offically known as a vacuolar ATPase complex) is a wonderfully complex collection of proteins. Joe Thornton, a biologist at the University of Oregon, and his colleagues wondered how this pump came to be. The closest major group of species to fungi are animals. The scientists compared the genes for these ring proteins to other genes in order to reconstruct their evoluationary history. By comparing Vma3 and Vma11 in yeast, Thornton and his colleagues were able to infer the structure of their ancestral protein.

Science Daily: News & Articles in Science, Health, Environment & Technology Giant Galapagos tortoise extinct for 150 years might still be alive | ZME Science Giant Galapagos Tortoises in Isabela Island, Galapagos. Adults of large subspecies can weigh over 300 kilograms (660lb) and measure 1.2 meters (4 ft) long. Although the maximum life expectancy of a wild tortoise is unknown, the average life expectancy is estimated to be 200 years. A subspecies of the the giant Galapagos tortoise, Chelonoidis elephantopus, long thought to be extinct for more than 150 years, is now believed to might still exist, scientists say. Yale University researchers conducted a highly thorough genetic analysis of various Galapagos giant tortoises in the region, which allowed them to speculate that at least a few dozen specimens of the elusive Chelonoidis elephantopus might still be alive! In 1835 during his antological Beagle expedition to the archipelago, Charles Darwin extensively studied the giant tortoises there, which he reserved a special chapter in his theory of evolution by natural selection. source

Marine Cyanobacteria Shed Billions of DNA-Containing Vesicles Scientists have recently discovered and documented the first extracellular, DNA-containing vesicles shed by ocean microbes. The marine cyanobacteria – photosynthesizing, prokaryotic bacteria that are ubiquitous to most terrestrial and aquatic habitats – are involved in Earth’s biogeochemical and nutrient cycles. During photosynthesis, the bacteria harness sunlight to convert light energy into chemical energy, using carbon dioxide and water and releasing molecular oxygen as a byproduct. Scientists at the Massachusetts Institute of Technology (MIT) have discovered another potential role of cyanobacteria. Autofluorescence seen in synechococcus bacteria. The latest research was published by post doctorate researcher Steven Biller and Professor Sallie Chisholm, along with their co-authors, in the journal Science. Prochlorococcus is a genus of remarkably small bacteria, less than a micrometer in length, that was discovered over 20 years ago. Vesicle-Mediated Transfer Between Bacteria Sources:

Trees Cocooned in Webs After Flood Photograph courtesy Russell Watkins, U.K. Department for International Development Trees shrouded in ghostly cocoons line the edges of a submerged farm field in the Pakistani village of Sindh, where 2010's massive floods drove millions of spiders and possibly other insects into the trees to spin their webs. Beginning last July, unprecedented monsoons dropped nearly ten years' worth of rainfall on Pakistan in one week, swelling the country's rivers. The water was slow to recede, creating vast pools of stagnant water across the countryside. "It was a very slow-motion kind of disaster," said Russell Watkins, a multimedia editor with the U.K.' According to Watkins, who photographed the trees during a trip to Pakistan last December, people in Sindh said they'd never seen this phenomenon before the flooding. (See pictures: "World's Biggest, Strongest Spider Webs Found.") As for what exactly had spun the webs, Watkins said: "There wasn't a scientific analysis of this being done. —Ker Than

Wrestling ninjas – why sabre-toothed predators have massive arms | Not Exactly Rocket Science A cat-like animal explodes from the long grass and leaps onto an antelope. Its huge bulk drags the target to the ground and its muscled forelegs pin it down. With two long sabre-shaped canine teeth, it stabs its victim in the throat, just the once, severing its blood vessels and windpipe. Death comes quickly. The hunter could be Smilodon, a sabre-toothed cat that lived throughout North and South America, around one or two million years ago. Or, it could be a nimravid, another group of hunters that looked like cats, but belonged to a separate, closely-related family. Or, it could be Barbourofelis, a member of yet another group of sabre-toothed not-quite-cats, which lived between 16 and 9 million years ago. Julie Meachen-Samuels from the National Evolutionary Synthesis Center has shown that all three groups shared the same adaptations: massive powerful front legs for pinning their prey, and strikingly large canines for delivering precise one-hit kills. Reference: Meachen-Samuels. 2011.

Fossils Reveal Secrets of Insects' Weird Ears | Evolution of Hearing | Fossil Insects & Green River Formation Various species of insects boast ears in the strangest places, including on their necks and under their wings. Now, a new examination of 50-million-year-old cricket and katydid fossils finds that these odd ears evolved before even the appearance of the predators that these ears can hear. Crickets, moths and other flying insects can hear the ultra high-pitched sonar of hunting bats, a talent that helps them avoid being eaten. "Their bat-detecting abilities may have simply become apparent later," study researcher Dena Smith of the University of Colorado, Boulder, said in a statement. Insects have evolved ears at least 17 times in different lineages, and other insects, such as the blue morpho butterfly, may even be able to distinguish between low and high pitches with their primitive under-wing ears. That level of detail is key, because the researchers were looking for katydid and cricket ears. "The next step," Smith said, "is to look for ears in other insect groups."

Yılın kitabı Türkiye'den - Doğal Hayat Güncelleme: 09:45 TSİ 02 Ocak. 2012 Pazartesi KuzeyDoğa Derneği Başkanı Doç. Dr. Çevre, doğa tarihi ve yaban hayat konularında dünyanınen kapsamlı ve saygın yayınevi olan İngiliz Natural History Book Service, 2011yılında yayınlanmış, en ilginç, orijinal ve bilgilendirici, okuyuculara yeni bakış açıları kazandıran, eski konulara yeni yaklaşımlar getiren ve insanları daha fazla anlamaya ve araştırmaya yönelten 10 kitap listesini yayınladı. Yayınevi 2011’de yılın kitabı seçtiği bu kitaplailgili yaptığı açıklamada şu sözlere yer verdi, “Kuşlar, hâli hazırda etkilerini gördüğümüz iklim değişikliği konusunda bizi uyarıyor. Düşük Yüksek 24 kullanıcıdan 4.5 puan.

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