Bacteria make major evolutionary shift in the lab - life - 09 June 2008 A major evolutionary innovation has unfurled right in front of researchers' eyes. It's the first time evolution has been caught in the act of making such a rare and complex new trait. And because the species in question is a bacterium, scientists have been able to replay history to show how this evolutionary novelty grew from the accumulation of unpredictable, chance events. Twenty years ago, evolutionary biologist Richard Lenski of Michigan State University in East Lansing, US, took a single Escherichia coli bacterium and used its descendants to found 12 laboratory populations. The 12 have been growing ever since, gradually accumulating mutations and evolving for more than 44,000 generations, while Lenski watches what happens. Profound change Mostly, the patterns Lenski saw were similar in each separate population. Indeed, the inability to use citrate is one of the traits by which bacteriologists distinguish E. coli from other species. Rare mutation? Evidence of evolution Promoted Stories
Extraterresterial Life Exists, Scientist Chandra Wickramasinghe Claims If a group of scientists are correct, tiny fossils uncovered inside a meteorite found in Sri Lanka in December are proof of extraterrestrial life. In a detailed paper called "Fossil Diatoms In A New Carbonaceous Meteorite" that is appearing in the Journal of Cosmology, Chandra Wickramasinghe claims to have found strong evidence that life exists throughout the universe. An electron microscope was used to study the reported remains of a large meteorite (see image below right) that fell near the Sri Lanka village of Polonnaruwa on Dec. 29. Wickramasinghe is the director of the Buckingham Centre for Astrobiology at the University of Buckingham in the U.K. Wickramasinghe and the late English astronomer Sir Fred Hoyle co-developed a theory known as "panspermia," which suggests that life exists throughout the universe and is distributed by meteoroids and asteroids. But with any remarkable claim comes criticism of the scientist's research and conclusions. Loading Slideshow
Baba Brinkman’s Rap Guide to Evolution Science and hip-hop? “Never the twain shall meet,” you may cry, and until recently, I’d have agreed with you on that one, fo’ shizzle. But then I stumbled across a collaboration which challenges that assumption. Baba Brinkman’s Rap Guide to Evolution is interesting, intelligent and funny hip-hop about evolutionary theory. The video below, “Natural Selection”, has its tongue firmly in its cheek, featuring a dance-off between Darwin and some of his best-known opponents, including the perennial favourite, God, and a more modern proponent of creationism, Sarah Palin. Fellow SciAm blogger Kevin Zelnio wrote about Baba back in November, but this unique rapper warrants a bit more attention – and a few links to his official music videos. With a little financial help from the Wellcome Trust, Baba has written 10 tracks about different aspects of evolutionary theory, and what it can tell us about modern life. I hope you enjoy them as much as I did – a happy new yizzle to you all!
Same Genes, Different Fates | Discoveries Eppie Lederer and Pauline Phillips were one of the most famous pairs of identical twins in the United States during the 20th century. Born 17 minutes apart, both women became wildly popular syndicated columnists—as Ann Landers and Abigail Van Buren, respectively—and dispensed tart-tongued advice about love and other matters. Photos from their younger days reveal that the two women were uncanny look-alikes, both graced with fashion-model cheekbones and vibrant eyes. Over the years, ever-changing hairstyles made it easier to tell them apart. But it was their dramatically diverging health, finally, that truly distinguished one from the other. Yet if DNA is not destiny, how is it that genes and environmental influences interact to bring about disease? As the name suggests, the epigenome acts directly on genes, the basic units of heredity. The body’s complete library of DNA, known as the genome, is found in every cell. The most-studied form of epigenetic modification is DNA methylation.
The History and Geography of Inventions [Home Page][Other Page] [Search Inventions] [Before 10,000 BC][10,000 BC to 4000 BC][4000 BC to 3000 BC][3000 BC to 2000 BC][2000 BC to 1000 BC][1000 BC to 1 BC][1 AD to 1000 AD][1000 to 1500][1500 to 1700][1700 to 1800][1800 to 1850][1850 to 1900][1900 to 1950][Since 1950] [Inventions][Biographies][Religions of the World][Bible Contradictions][Rain][Countries of the World][Cookery][Music][Composers (Opera)] [Readers' Feedback (Religion)] [Language][Travel][Eclipses][London][Astronomy][Mathematics][Physics][Chemistry][Biology][Football][Television][Other] Sponsored Link Atlas of the Human Journey - The Genographic Project When humans first ventured out of Africa some 60,000 years ago, they left genetic footprints still visible today. By mapping the appearance and frequency of genetic markers in modern peoples, we create a picture of when and where ancient humans moved around the world. These great migrations eventually led the descendants of a small group of Africans to occupy even the farthest reaches of the Earth. Our species is an African one: Africa is where we first evolved, and where we have spent the majority of our time on Earth. According to the genetic and paleontological record, we only started to leave Africa between 60,000 and 70,000 years ago. Once the climate started to improve, after 70,000 years ago, we came back from this near-extinction event. Slightly later, a little after 50,000 years ago, a second group appears to have set out on an inland trek, leaving behind the certainties of life in the tropics to head out into the Middle East and southern Central Asia.
Trees of Life: A Visual History of Evolution by Maria Popova Mapping 450 years of mankind’s curiosity about the living world and the relationships between organisms. Since the dawn of recorded history, humanity has been turning to the visual realm as a sensemaking tool for the world and our place in it, mapping and visualizing everything from the body to the brain to the universe to information itself. Trees of Life: A Visual History of Evolution (public library) catalogs 230 tree-like branching diagrams, culled from 450 years of mankind’s visual curiosity about the living world and our quest to understand the complex ecosystem we share with other organisms, from bacteria to birds, microbes to mammals. Theodore W. Pietsch writes in the introduction: The tree as an iconographic metaphor is perhaps the most universally widespread of all great cultural symbols. 'Genealogy of the class of fishes' published by Louis Agassiz in his Recherches sur les poissons fossiles (Research on fossil fishes) of 1844. Share on Tumblr
Understanding Evolution The bacteria that changed the world - May, 2017 The make-up of Earth's atmosphere, once the domain of Earth science textbooks, has become an increasingly "hot" news topic in recent decades, as we struggle to curb global warming by limiting the carbon dioxide that human activity produces. While the changes that humanity has wrought on the planet are dramatic, this isn’t the first time that one species has changed Earth’s atmosphere. Three billion years ago, there was no free oxygen in the atmosphere at all. Life was anaerobic, meaning that it did not need oxygen to live and grow. Read the rest of the story here | See the Evo in the News archive
Delicatessen with love | gabriele galimberti Eat, Eat, Eat!!! From Grandma with love I will never forget grandma Sara’s artichokes. They have become a cult since when a famous Spanish cooking blog published their recipe, which I transcribed from memory, following the thread of the taste left in my mouth (just like Proust’s madeleine). Gabriele Galimberti pays homage to all the grandmothers in the world and to their love for good cooking, starting from his own grandma Marisa who, before the departure for his tour around the world by couchsurfing, took care to prepare her renowned ravioli. She was not so concerned about the possible risks or mishaps her grandson might face in his adventurous travelling worldwide, but her major worry was, “what will he eat?”. Buonappetito! Arianna Rinaldo
Looking Back: NASA's "Mono Lake Discovery" --What Did They Really Find? (A 2011 Most Popular) Dec. 2, 2010: NASA-supported researchers announced that they had discovered the first known microorganism on Earth able to thrive and reproduce using the toxic chemical arsenic. The microorganism, which lives in 740,000 year old California's Mono Lake, substitutes arsenic for phosphorus in the backbone of its DNA and other cellular components. "The definition of life has just expanded," said Ed Weiler, NASA's associate administrator for the Science Mission Directorate at the agency's Headquarters in Washington. This finding of an alternative biochemistry makeup will alter biology textbooks and expand the scope of the search for life beyond Earth, NASA suggested. "Biological dependence on the six major nutrient elements carbon, hydrogen, nitrogen, oxygen, sulfur, and phosphorus is complemented by a selected array of other elements, usually metal(loid)s present in trace quantities that serve critical cellular functions, such as enzyme co-factors.
Family trees of ancient bacteria reveal evolutionary moves A geomicrobiologist at Washington University in St. Louis has proposed that evolution is the primary driving force in the early Earth’s development rather than physical processes, such as plate tectonics. Carrine Blank, Ph.D., Washington University assistant professor of geomicrobiology in the Department of Earth & Planetary Sciences in Arts & Sciences, studying Cyanobacteria - bacteria that use light, water, and carbon dioxide to produce oxygen and biomass - has concluded that these species got their start on Earth in freshwater systems on continents and gradually evolved to exist in brackish water environments, then higher salt ones, marine and hyper saline (salt crust) environments. Carrine Blank/WUSTL Photo A hot spring at old faithful in Yellowstone National Park, Wyoming. A WUSTL scientist suggests that Cyanobacteria arose in freshwater environments rather than in the sea. Cyanobacteria are organisms that gave rise to chloroplasts, the oxygen factory in plant cells.