background preloader

Evolution, de l'origine de la vie aux origines de l'homme - CNRS - Sagascience

Evolution, de l'origine de la vie aux origines de l'homme - CNRS - Sagascience

http://www.cnrs.fr/cw/dossiers/dosevol/

Related:  EvolutionEvolutionRessources sciences et géo

Evolution - Home Mark Ridley's Evolution has become the premier undergraduate text in the study of evolution. Readable and stimulating, yet well balanced and in-depth, this text tells the story of evolution, from the history of the study to the most recent developments in evolutionary theory. The third edition of this successful textbook features updates and extensive new coverage. How Life Evolved on Earth, Alien Life Evolution Clues to how life evolved, not only on this planet but also possibly on alien worlds, might be found in underwater caves in the Bahamas, researchers say. The caves in question are called "blue holes," so-named because from the air, their entrances appear circular in shape, with different shades of blue water in and around them. There are estimated to be more than 1,000 such caves in the Bahamas, the greatest concentration of blue holes in the world. "It's really incredible to be swimming down a passage that no one has ever been in before, to experience that thrill of discovery," said researcher Tom Iliffe, a marine biologist at Texas A&M University at Galveston. "At the bottom of a cave, there's no telling what might be around the next corner."

VPL: Directory Page [Lab I][Lab II][Lab III][Lab IV][Lab V][Lab VI][Lab VII][Lab VIII][Lab IX][Lab X][Lab XI][Lab XII] What are the synapomorphies for land plants? What does it take? Strange Life Found in Underwater Caves The Bahamas have more than 1,000 underwater caves, how many of them have their own unique ecosystem? Microbiologists examined neighboring blue holes and were surprised to find a different set of microbes in each. Less than 5 percent of Earth's underwater cave systems have been scientifically investigated. Clues to how life evolved, not only on this planet but also possibly on alien worlds, might be found in underwater caves in the Bahamas, researchers say.

Strange life found in underwater caves - Biologists finding new microbes totally unknown elsewhere on Earth Clues to how life evolved, not only on this planet but also possibly on alien worlds, might be found in underwater caves in the Bahamas, researchers say. The caves in question are called "blue holes," so-named because from the air, their entrances appear circular in shape, with different shades of blue water in and around them. There are estimated to be more than 1,000 such caves in the Bahamas, the greatest concentration of blue holes in the world.

Szostak Lab: Home We are interested in the chemical and physical processes that facilitated the transition from chemical evolution to biological evolution on the early earth. As a way of exploring these processes, our laboratory is trying to build a synthetic cellular system that undergoes Darwinian evolution. Our view of what such a chemical system would look like centers on a model of a primitive cell, or protocell, that consists of two main components: a self-replicating genetic polymer and a self-replicating membrane boundary. The job of the genetic polymer is to carry information in a way that allows for both replication and variation, so that new sequences that encode useful functions can be inherited and can further evolve. The role of the protocell membrane is to keep these informational polymers localized, so that the functions they encode lead to an advantage in terms of their own replication or survival.

Darwin Online: Darwin's Publications British Entomology [←click finches for illustrations] 1829-1832. [Records of captured insects]. In Stephens, Illustrations of British entomology. <em>New Scientist</em> Weighs in on the Origin of Life This week's issue of New Scientist contains an interesting article bearing the headline "First Life: The Search for the First Replicator." As a means to circumvent the chicken-and-egg problem pertinent to the relationship of DNA and proteins, author Michael Marshall attempts to revive the fashionable (but scientifically bankrupt) scenario of an RNA world. In brief, RNA exhibits both information-carrying capacity and catalytic activity. Arguments for the RNA world include the fact that RNA makes up a large proportion of ribosomes (the protein factory of the cell).

Origins by Lucas Laursen Charles Darwin may have had his biggest impact on biology, but he began his scientific career as a geologist. So it’s appropriate that earlier this year, retired geologist John Ramsay, who had long studied the famed biologist’s life, accepted a commission to compose a Darwin-themed string quartet. Kuhn's Physical Chemistry It was early considered as a mystery how a genetic apparatus, the basic machinery of life, could have originated. In 1972 a sequence of hypthetical steps leading to such a genetic apparatus was invented *. These steps are all logically consistent and chemical reasonable. It was an argument against such a belief of a mystery on origin of life.

New Evidence Challenges Oldest Signs of Life Carbon found within ancient rocks has played a crucial role developing a time line for the emergence of biological life on the planet billions of years ago. But applying cutting-edge technology to samples of ancient rocks from northern Canada has revealed the carbon-based minerals may be much younger than the rock they inhabit, a team of researchers report in the latest edition of the journal Nature Geoscience. The team – which includes researchers from Boston College, the Carnegie Institution of Washington, NASA's Johnson Space Center and the Naval Research Laboratory – says new evidence from Canada's Hudson Bay region shows carbonaceous particles are millions of years younger than the rock in which they're found, pointing to the likelihood that the carbon was mixed in with the metamorphic rock later than the rock's earliest formation – estimated to be 3.8 to 4.2 billion years ago.

The Origin of Life Challenge Post: July 27, 2012 12:34 am Author: Marlene Rosen Source: ETVOL Guest Contributor With the recent release of Prometheus, the media has asked again, what is the origin of life? The movie questions if life on earth was created by aliens. With the use of Hollywood stunts and some black organic matter, the answer to this question is still the same as it has been: further investigation is necessary. Harry Lonsdale, a retired chemist, seeks to answer this question scientifically rather than fictionally. In mid- 2011 he proposed a challenge to the scientific community to come up with ideas to explain the mechanisms of life’s origin.

Origin of life: Hypothesis traces first protocells back to emergence of cell membrane bioenergetics A coherent pathway -- which starts from no more than rocks, water and carbon dioxide and leads to the emergence of the strange bio-energetic properties of living cells -- has been traced for the first time in a major hypothesis paper in Cell this week. At the origin of life the first protocells must have needed a vast amount of energy to drive their metabolism and replication, as enzymes that catalyse very specific reactions were yet to evolve. Most energy flux must have simply dissipated without use. So where did it all that energy come from on the early Earth, and how did it get focused into driving the organic chemistry required for life? The answer lies in the chemistry of deep-sea hydrothermal vents.

Abiogenesis - EvoWiki From EvoWiki The term abiogenesis simply means getting life from non-life and is used both for spontaneous generation and for chemical evolution. While chemical evolution refers to the process by which the first living entities are thought to have appeared on a lifeless Earth, spontaneous generation refers to the, now discredited, theory that small animals and bacteria are spontaneously generated at the present time. Biological evolution Main article: Evolution is baseless without a theory of abiogenesis It is worth noting that creationists frequently confuse abiogenesis with evolution.

Related: