Timeline: The evolution of life - life - 14 July 2009 Read full article Continue reading page |1|2|3|4 There are all sorts of ways to reconstruct the history of life on Earth. Pinning down when specific events occurred is often tricky, though. For this, biologists depend mainly on dating the rocks in which fossils are found, and by looking at the "molecular clocks" in the DNA of living organisms. There are problems with each of these methods. Modern genetics allows scientists to measure how different species are from each other at a molecular level, and thus to estimate how much time has passed since a single lineage split into different species. These difficulties mean that the dates in the timeline should be taken as approximate. 3.8 billion years ago? This is our current "best guess" for the beginning of life on Earth. , and was probably based on RNA rather than DNA. At some point far back in time, a common ancestor gave rise to two main groups of life: bacteria and archaea. 3.5 billion years ago 3.46 billion years ago 3.4 billion years ago
Did life evolve in a ‘warm little pond’? | Thoughtomics Geothermal pond near the Mutnovsky volcano, Kamtchatka. Copyright Anna S. Karyagina “But if (and oh what a big if) we could conceive in some warm little pond with all sorts of ammonia and phosphoric salts, light, heat, electricity etcetera present, that a protein compound was chemically formed, ready to undergo still more complex changes [..] ” ~Charles Darwin, in a letter to Joseph Hooker (1871) All life on earth is related. Trace back the separate lines of descent of all organisms that ever lived, and they will converge to a single point of origin – the beginning of life. A new and controversial study suggests Darwin’s stab in the dark hit close to truth. The researchers, led by Armen Mulkidjanian, presume that the chemistry of modern cells mirror the original environment in which life first evolved. The researchers invented the term ‘chemistry conservation principle’ for their idea that organisms retain their chemical traits throughout time. This is not a new approach.
Free conservation biology textbook: Conservation Biology for All Oxford University Press makes conservation biology textbook by some of the world's most prominent ecologists and conservation biologists available as free download Conservation Biology for All provides cutting-edge but basic conservation science to a global readership. A series of authoritative chapters have been written by the top names in conservation biology with the principal aim of disseminating cutting-edge conservation knowledge as widely as possible. The global biodiversity crisis is now unstoppable; what can be saved in the developing world will require an educated constituency in both the developing and developed world. Features "If a book could receive a standing ovation - this one is a candidate. Conservation Biology for All is a textbook that aims to be a one-stop shop for conservation education. About the Editors Navjot S. Paul R. Other authors Andrew F. Free Access See the box on the right to freely download chapters, or the entire text, of the book.
'New frontier' of Antarctic lake exploration 16 February 2012Last updated at 12:23 By Paul Rincon Science editor, BBC News website Vostok station is one of the most difficult places to work on Earth When a Russian drilling team reached Antarctica's Lake Vostok last week, they were able to claim a world first. No one had previously penetrated one of the continent's sub-glacial lakes, prompting Valery Lukin from the Arctic and Antarctic Research Institute (AARI) in St Petersburg to liken his team's achievement to the Moon landings in 1969. Whatever the comparison, it represents a remarkable feat. Over 20 years of stop-start drilling, the Russian team ground their way through 3.7km (2.3mi) of solid ice, working in one of the most inhospitable environments on Earth. The Vostok project is one of several similar ventures being undertaken in the world's last wilderness. Together, they form a huge and only partially connected network. Conditions in Antarctic lakes may not be so different to those on icy moons such as Europa Faster method
Evolver Zone Meet plants' and algae's common ancestor: Primitive organisms not always so simple, researcher says A University of Arkansas biologist has created a sketch of what the first common ancestor of plants and algae may have looked like. He explains that primitive organisms are not always simple. The image appears as part of a "Perspective" article in the Feb. 17 issue of Science. Fred Spiegel, professor of biological sciences in the J. "The work that Price and his group did nailed down what the relationships are" between this organism, the algae and plants, and all other eukaryotes, organisms that have a true nucleus in their cells, Spiegel said. For many years, scientists have speculated that the original ancestor of plants and algae must have originated from a protozoan-like organism and cyanobacteria. However, other scientists argued that the diversity and complexity of plants and algae suggest multiple events where different organisms merged. Price and his colleagues' studied the genome of an obscure alga called Cyanophora.
Evolution: Education and Outreach - Free Access Available As of January 2013 Evolution: Education & Outreach is a peer-reviewed open access journal published under the brand SpringerOpen. From 2013 onward all new articles published in the journal are freely and permanently available online for anyone, anywhere and at any time. This journal promotes accurate understanding and comprehensive teaching of evolutionary theory for a wide audience. Evolution: Education and Outreach addresses the question of why we should care about evolution by exploring the practical applications of evolutionary principles in daily life and the impact of evolutionary theory on culture and society throughout history. Targeting K-16 students, teachers and scientists alike, the journal presents articles to aid members of these communities in the teaching of evolutionary theory. It connects teachers with scientists by adapting cutting-edge, peer reviewed articles for classroom use on varied instructional levels.
How the First Plant Came to Be Earth is the planet of the plants—and it all can be traced back to one green cell. The world's lush profusion of photosynthesizers—from towering redwoods to ubiquitous diatoms—owe their existence to a tiny alga eons ago that swallowed a cyanobacteria and turned it into an internal solar power plant. By studying the genetics of a glaucophyte—one of a group of just 13 unique microscopic freshwater blue-green algae, sometimes called "living fossils"—an international consortium of scientists led by molecular bioscientist Dana Price of Rutgers University, has elucidated the evolutionary history of plants. The glaucophyte Cyanophora paradoxa still retains a less domesticated version of this original cyanobacteria than most other plants. According to the analysis of C. paradoxa's genome of roughly 70 million base pairs, this capture must have occurred only once because most modern plants share the genes that make the merger of photosynthesizer and larger host cell possible.
The Unofficial Stephen Jay Gould Archive Saturn's Titan: Clues to the Origins of Life in the Universe? "When we designed the original tour for the Cassini spacecraft, we really did not know what we would find, especially at Enceladus and Titan," said Dennis Matson, the JPL Cassini project scientist. Unlike Earth, Titan's lakes, rivers and rain are composed of methane and ethane, and temperatures reach a chilly minus 180 degrees Celsius (minus 290 degrees Fahrenheit). Although Titan's dense atmosphere limits viewing the surface, Cassini's high-resolution radar coverage and imaging by the infrared spectrometer have given scientists a better look. Titan has hundreds of times more liquid hydrocarbons than all the known oil and natural gas reserves on Earth, according to new data from NASA's Cassini spacecraft. At an eye popping minus 179 degrees Celsius (minus 290 degrees Fahrenheit), Titan has a surface of liquid hydrocarbons in the form of methane and ethane with tholins believed to make up its dunes. Cassini has mapped about 20 percent of Titan's surface with radar.
An Error Occurred Setting Your User Cookie This site uses cookies to improve performance. If your browser does not accept cookies, you cannot view this site. Setting Your Browser to Accept Cookies There are many reasons why a cookie could not be set correctly. You have cookies disabled in your browser. Why Does this Site Require Cookies? This site uses cookies to improve performance by remembering that you are logged in when you go from page to page. What Gets Stored in a Cookie? This site stores nothing other than an automatically generated session ID in the cookie; no other information is captured. In general, only the information that you provide, or the choices you make while visiting a web site, can be stored in a cookie.
Lithium Isotope History of Cenozoic Seawater: Change... [Science. 2012 Abstract search | Walcott 2009 Climate change threatens tropical birds Public release date: 15-Feb-2012 [ Print | E-mail Share ] [ Close Window ] Contact: Lee Siegellee.siegel@utah.edu 801-581-8993University of Utah SALT LAKE CITY -- Climate change spells trouble for many tropical birds – especially those living in mountains, coastal forests and relatively small areas – and the damage will be compounded by other threats like habitat loss, disease and competition among species. That is among the conclusions of a review of nearly 200 scientific studies relevant to the topic. There are roughly 10,000 bird species worldwide. He points out that already, "12.5 percent of the world's 10,000 bird species are threatened with extinction" – listed as vulnerable, endangered or critically endangered by the International Union for Conservation of Nature ( Wormworth and Şekercioğlu coauthored the 2011 book, "Winged Sentinels: Birds and Climate Change." Putting the Heat on Tropical Birds The researchers say studies indicate: Scenarios for Extinction