The Information Theory of Life. There are few bigger — or harder — questions to tackle in science than the question of how life arose. We weren’t around when it happened, of course, and apart from the fact that life exists, there’s no evidence to suggest that life can come from anything besides prior life. Which presents a quandary. Christoph Adami does not know how life got started, but he knows a lot of other things. His main expertise is in information theory, a branch of applied mathematics developed in the 1940s for understanding information transmissions over a wire. Since then, the field has found wide application, and few researchers have done more in that regard than Adami, who is a professor of physics and astronomy and also microbiology and molecular genetics at Michigan State University. He takes the analytical perspective provided by information theory and transplants it into a great range of disciplines, including microbiology, genetics, physics, astronomy and neuroscience.
Yes. Biologist’s new book details a new era in the study of evolution | Harvard Gazette. Three years ago, when Harvard biologist Jonathan Losos settled in at the Geological Lecture Hall for a talk by fellow scientist Richard Lenski, he was toying with the idea of writing a book on evolution. When the lecture was over, he was done toying. Losos, an evolutionary biologist and the Monique and Philip Lehner Professor for the Study of Latin America, said the work described by Michigan State’s Lenski filled in a picture partly painted by experiments Losos already knew about — some of which he had conducted himself, with lizards from the genus Anolis, commonly called anoles, on islands in the Caribbean.
Lenski’s research approximated what the late Harvard paleontologist Stephen Jay Gould, who wrote extensively about evolution, might have described as “replaying the tape of life,” Losos said. “Gould had suggested that if we could somehow replay the tape — start evolution over again from the same starting point, then we get a very different outcome,” Losos said. Leaving Facebook. What the ctenophore says about the evolution of intelligence | Aeon Essays. Leonid Moroz has spent two decades trying to wrap his head around a mind-boggling idea: even as scientists start to look for alien life in other planets, there might already be aliens, with surprisingly different biology and brains, right here on Earth.
Those aliens have hidden in plain sight for millennia. They have plenty to teach us about the nature of evolution, and what to expect when we finally discover life on other worlds. Moroz, a neuroscientist, saw the first hint of his discovery back in the summer of 1995, not long after arriving in the United States from his native Russia. He spent that summer at the Friday Harbor marine laboratory in Washington. He trained his eyes to recognise its bulbous, transparent body in the sunlit water: an iridescent glint and fleeting shards of rainbow light, scattered by the rhythmic beating of thousands of hair-like cilia, propelling it through the water.
If evolution were re-run here on Earth, would intelligence arise a second time? First Support for a Physics Theory of Life. Often, the system settles into an equilibrium state, where it has a balanced concentration of chemicals and reactions that just as often go one way as the reverse. This tendency to equilibrate, like a cup of coffee cooling to room temperature, is the most familiar outcome of the second law of thermodynamics, which says that energy constantly spreads and the entropy of the universe always increases.
(The second law is true because there are more ways for energy to be spread out among particles than to be concentrated, so as particles move around and interact, the odds favor their energy becoming increasingly shared.) But for some initial settings, the chemical reaction network in the simulation goes in a wildly different direction: In these cases, it evolves to fixed points far from equilibrium, where it vigorously cycles through reactions by harvesting the maximum energy possible from the environment. Form and Function Information Processors. No, Evolution Is Not Always Dog-Eat-Dog. Violence has been the sire of all the world’s values,” wrote poet Robinson Jeffers in 1940.
“What but the wolf’s tooth whittled so fine the fleet limbs of the antelope? What but fear winged the birds, and hunger jeweled with such eyes the great goshawk’s head?” We’ve taken these metaphors for evolution to heart, reading them to mean that life is a race to kill or be killed. “Darwinian” stands in for “cutthroat,” “survival of the fittest” signifies survival of the ruthless. We see selective pressures that hone each organism for success and drive genetic innovation as the natural order of things. But we know now that that picture is incomplete. One of the best ways to relax selective forces is to work together, something that mathematical biologist Martin Nowak has called the “snuggle for survival.”
The fitness of a species can be thought of as a multi-dimensional landscape defined by its compatibility with its environment. Also in Evolution We Built These Bodies By Dusica Sue Malesevic. Evolution Runs Faster on Short Timescales. In the 1950s, the Finnish biologist Björn Kurtén noticed something unusual in the fossilized horses he was studying. When he compared the shapes of the bones of species separated by only a few generations, he could detect lots of small but significant changes. Horse species separated by millions of years, however, showed far fewer differences in their morphology. Subsequent studies over the next half century found similar effects — organisms appeared to evolve more quickly when biologists tracked them over shorter timescales.
Then, in the mid-2000s, Simon Ho, an evolutionary biologist at the University of Sydney, encountered a similar phenomenon in the genomes he was analyzing. When he calculated how quickly DNA mutations accumulated in birds and primates over just a few thousand years, Ho found the genomes chock-full of small mutations. This indicated a briskly ticking evolutionary clock. Baffled by his results, Ho set to work trying to figure out what was going on. Gillman & Soame. Dividing Droplets Could Explain Origin of Life. A Break in the Search for the Origin of Complex Life - The Atlantic. In Norse mythology, humans and our world were created by a pantheon of gods who lived in the realm of Asgard.
As it turns out, these stories have a grain of truth to them. Thanks to a team of scientists led by Thijs Ettema, Asgard is now also the name of a large clan of microbes. Its members, which are named after Norse gods like Odin, Thor, Loki, and Heimdall, are found all over the world. Many of them are rare and no one has actually seen them under a microscope. But thanks to their DNA, we know they exist. And we know that they are singularly important to us, because they may well be the group from which we evolved. If Ettema is right, then around two billion years ago, an Asgardian microbe (or an incredibly close relative) took part in a unique event that gave rise to the eukaryotes.
To understand this story, we have to go back to the very beginning. Eukaryotic cells are generally much bigger than either bacteria or archaea. What were those two ancient partners like? How Old Is the Modern Human Mind? When I started learning about the Ice Age, the oldest known cave art dated to about 35,000 years ago—now it’s closer to 41,000 years. And while they seemed like a fairly intelligent species, Neanderthals weren’t thought to have been capable of creating art (the first confirmed Neanderthal cave art—an engraved crosshatch—was announced in 2014). Most researchers didn’t think our ancestors interbred with Neanderthals (but a number of them actually did around 60,000 years ago), and we definitely didn’t know that there was a third separate humanlike species called the Denisovans living in Ice Age Europe—and that some of us carry their genes, too.
The remarkable fact is that all of us living today are the end product of an incredible story of success against all odds: Each of us carries DNA that stretches back in an unbroken line to the beginnings of humanity and beyond. I was wrong. At first I had only a hunch that I was wrong—along with much of the literature. Also in Archaeology. Without a library of Platonic forms, evolution couldn’t work | Aeon Essays. When it slithers through the grass, the legless glass lizard is indistinguishable from a snake.
But harass it and it will perform a very un-snakelike feat. It will leave its tail behind – still wriggling – and slide away. That isn’t the only surprise the glass lizard has in store. A careful look also reveals inflexible jaws, movable eyelids, and ear openings. To organise the messy diversity of a million-plus different life forms, we need to sort them into the boxes we call species. Classification requires comparison. Get Aeon straight to your inbox But perhaps not. For Plato, the perceptible material world is like a faint shadow of a higher reality. A systematist’s task might be daunting, but it becomes manageable if each species is distinguished by its own Platonic essence.
The only problem: the glass lizard. But as has happened many times before, Plato might have the last word. The glass lizard itself comprises billions of cells. How do random DNA changes lead to innovation? Under Pressure, Does Evolution Evolve? In 1996, Susan Rosenberg, then a young professor at the University of Alberta, undertook a risky and laborious experiment. Her team painstakingly screened hundreds of thousands of bacterial colonies grown under different conditions, filling the halls outside her lab with tens of thousands of plates of bacteria. “It stank,” Rosenberg recalled with a laugh. “My colleagues hated me.” The biologist, now at Baylor College of Medicine in Houston, hoped to resolve a major debate that had rocked biology in different incarnations for more than 100 years.
Although Darwin’s ideas have clearly triumphed in modern biology, hints of a more Lamarckian style of inheritance have continued to surface. Baylor College of Medicine Susan Rosenberg, a biologist at Baylor College of Medicine in Houston, studies how bacteria mutate when under stress. Rosenberg’s results, published in 1997, disputed those findings, as other’s had before, but with a twist. Rosenberg expected the biology community to be relieved. Meet Luca, the Ancestor of All Living Things. Genes are adapted to an organism’s environment. So Dr. Martin hoped that by pinpointing the genes likely to have been present in Luca, he would also get a glimpse of where and how Luca lived. “I was flabbergasted at the result, I couldn’t believe it,” he said.
The 355 genes pointed quite precisely to an organism that lived in the conditions found in deep sea vents, the gassy, metal-laden, intensely hot plumes caused by seawater interacting with magma erupting through the ocean floor. Deep sea vents are surrounded by exotic life-forms and, with their extreme chemistry, have long seemed places where life might have originated. The 355 genes ascribable to Luca include some that metabolize hydrogen as a source of energy as well as a gene for an enzyme called reverse gyrase, found only in microbes that live at extremely high temperatures, Dr. Martin and colleagues reported Monday in Nature Microbiology. Dr. Others believe that the Luca that Dr. From Dr. Dr. Dr. Dr. Dr. How Burgers and Fries Are Killing Your Microbial Balance. For the microbiologist Justin Sonnenburg, that career-defining moment—the discovery that changed the trajectory of his research, inspiring him to study how diet and native microbes shape our risk for disease—came from a village in the African hinterlands.
A group of Italian microbiologists had compared the intestinal microbes of young villagers in Burkina Faso with those of children in Florence, Italy. The villagers, who subsisted on a diet of mostly millet and sorghum, harbored far more microbial diversity than the Florentines, who ate a variant of the refined, Western diet. Where the Florentine microbial community was adapted to protein, fats, and simple sugars, the Burkina Faso microbiome was oriented toward degrading the complex plant carbohydrates we call fiber. “It was the most different human microbiota composition we’d ever seen,” Sonnenburg told me.
Earlier this year I visited Sonnenburg at Stanford University, where he has a lab. Where did that diversity come from? The Surprising Origins of Life’s Complexity. Charles Darwin was not yet 30 when he got the basic idea for the theory of evolution. But it wasn’t until he turned 50 that he presented his argument to the world. He spent those two decades methodically compiling evidence for his theory and coming up with responses to every skeptical counterargument he could think of. And the counterargument he anticipated most of all was that the gradual evolutionary process he envisioned could not produce certain complex structures. Consider the human eye. It is made up of many parts—a retina, a lens, muscles, jelly, and so on—all of which must interact for sight to occur.
But Darwin could nonetheless see a path to the evolution of complexity. The human eye, Darwin argued, could have evolved from a simple light-catching patch of tissue of the kind that animals such as flatworms grow today. Darwin’s musings on the origin of complexity have found support in modern biology. A Sum of Varied Parts The Fruit-Fly Test Edward Kinsman Molecular Complexity. Do Organisms Become More Evolvable in Times of Stress? Updated on November 18, 2015 Imagine that you wake up in a pit, surrounded by people who are all wounded and bleeding. Something had clearly gone horribly wrong. Maybe you panic. Maybe you tend to the wounded.
Maybe you team up to plan an escape. But if you’re a red flour beetle, you do none of those things. Instead, you quietly become more evolvable. When Joachim Kurtz from the University of Münster placed healthy beetles among wounded peers, he found that they can unveil mutations that are present in their genomes but whose effects are usually masked.
Here’s how it works. Whether it will depends upon HSP90, a protein that helps other proteins to fold. This is, in fact, exactly what happens to animals under stressful conditions. Lindquist's team has since found that HSP90 stores genetic variation in bacteria, plants, yeast, and animals. These studies suggest that HSP90 is a major driving force in evolution, a way of tuning an organism’s evolvability. “The data are really startling!” Under Pressure, Does Evolution Evolve? The TimeTree of Life Book. Gordon's Introduction to The Earthlife Web. Evogeneao - - Tree of Life. Return to "Download Files" Page You are welcome to download the following graphic image of the Tree of Life for non-commercial, educational purposes: Tree of Life (~3,000 species, based on rRNA sequences) (pdf, 368 KB) (see Science, 2003, 300:1692-1697) This file can be printed as a wall poster.
Printing at least 54" wide is recommended. (If you would prefer a simplified version with common names, please see below.) Blueprint shops and other places with large format printers can print this file for you. Tree of Life tattoo, courtesy of Clare D'Alberto, who is working on her Ph.D. in biology at the University of Melbourne. Here is another great Tree of Life tattoo! Cover of Molecular Systmatics, 2nd ed Here is yet another version from Hannah Udelll at the University of Wisconson-Madisson. From the exhibit Massive Change:The Future of Global Design: Here is a version modified by artist Carol Ballenger, commissioned by a hospital: This figure has been printed and used in many places. Trees of Life: A Visual History of Evolution. Grand tree of life study shows a clock-like trend in new species emergence and diversity.
Unintelligent Design | Evolution. Evolution and the Unintelligent Design of Life: Inherited Traits, Genetic Dysfunction and Artificial Life. Yeast Study Suggests Genetics Are Random but Evolution Is Not | Quanta Magazine. A New Thermodynamics Theory of the Origin of Life. Evolution: Change: Deep Time. A Brief History of Life. The Evolution of Life on Earth. The father of all men is 340,000 years old - life - 06 March 2013. Human origins: Are we hybrids? How Many People Have Ever Lived on Earth?
The Human Story. Survey of Earliest Human Settlements Undermines Claim That War Has Deep Evolutionary Roots | Cross-Check. Early Primate Evolution: Time Scale of the Earth. Chris Stringer on the Origins and Rise of Modern Humans. Baffling 400,000-Year-Old Clue to Human Origins. Skull of Homo erectus throws story of human evolution into disarray | Science. Tiny, insect-eating animal becomes earliest known primate | Science. WATCH: The Surprising Reason We Find Babies Cute | Dan Dennett. Ecosystems still feel the pain of ancient extinctions - life - 11 August 2013.
The Botany of Desire - Full Length High Definition. Bird Study Questions a Driving Force in Evolution. Who’s in Charge Inside Your Head? Sci-Tech / Science : Scientists decode how life emerged from Earth’s abiotics. Extraterresterial Life Exists, Scientist Chandra Wickramasinghe Claims. What Are The Odds Of Finding Extraterrestrial Intelligent Life? 'Radiation-eating' Fungi Finding Could Trigger Recalculation Of Earth's Energy Balance And Help Feed Astronauts.
Researchers use Moore's Law to calculate that life began before Earth existed. Astrobiologists discover fossils in meteorite fragments, confirming extraterrestrial life. The truth IS out there: British scientists claim to have found proof of alien life - Science - News. The Single Theory That Could Explain Emergence, Organisation And The Origin of Life. Chiral Key Found to Origin of Life. Earth's first life may have sprung up in ice - life - 01 November 2013. In Search of Life’s Smoking Gun - Issue 17: Big Bangs. Family trees of ancient bacteria reveal evolutionary moves. Bacteria make major evolutionary shift in the lab - life - 09 June 2008. A New Approach to Building the Tree of Life.