Birth of New Species Witnessed by Scientists

Birth of New Species Witnessed by Scientists | Wired Science | Wired.com

New species can emerge very quickly — and sometimes all it takes is a song.

O diferenta de doua molecule la o gena aproape identica la om si la cimpanzeu ar putea reprezenta originea facultatii de a vorbi

O diferenta de doua molecule la o gena aproape identica la om si la cimpanzeu ar putea reprezenta originea facultatii de a vorbi – studiu – Esential – HotNews.ro

O simpla diferenta de doua molecule ale unei gene altminteri identica la om si la cimpanzeu ar putea reprezenta originea facultatii de a vorbi, potrivit unui studiu publicat miercuri de revista Nature si citat de AFP.

Scientists Reproduce a Building Block of Life in Laboratory

Scientists Reproduce a Building Block of Life in Laboratory

“We have demonstrated for the first time that we can make uracil, a component of RNA, non-biologically in a laboratory under conditions found in space,” said Michel Nuevo, research scientist at NASA’s Ames Research Center, Moffett Field, Calif. “We are showing that these laboratory processes, which simulate occurrences in outer space, can make a fundamental building block used by living organisms on Earth.”
…
“Nobody really understands how life got started on Earth. Our experiments demonstrate that once the Earth formed, many of the building blocks of life were likely present from the beginning. Since we are simulating universal astrophysical conditions, the same is likely wherever planets are formed,” explained Sandford.

YouTube – The Origin of Genes

YouTube – The Origin of Genes

Superstitious Beliefs Cemented Before Birth

Superstitious Beliefs Cemented Before Birth : Discovery News

Oct. 30, 2009 — The propensity to believe in paranormal phenomena and superstitions appears to arise in the womb, suggests new research.

The findings, published in the journal Personality and Individual Differences, further indicate that a reduced ability for analytical thinking may correspond with increased intuitive thinking, which has been associated with a belief in extrasensory perception (ESP), ghosts, telepathy and other paranormal phenomena.

Author Martin Voracek claims his new study’s determinations “suggest (there are) biologically based, prenatally programmed influences on paranormal and superstitious beliefs.”

“Or, paraphrasing the probably best-known slogan from the defining X-Files television series: It may well be that some of the truth is in the womb, rather than out there,” added Voracek, a University of Vienna psychologist.

His study participants consisted of 1,118 Austrian men and women from diverse backgrounds. They ranged in age from 17 to 72.

Voracek first had the test subjects complete an established survey that psychologists and other researchers use to assess a subject’s paranormal beliefs and experiences. The questions addressed related abilities, such as ESP and psychokinesis, which is the power to move something by thinking about it.

Never Say Die: Why We Can’t Imagine Death

Never Say Die: Why We Can’t Imagine Death: Scientific American

Consider the rather startling fact that you will never know you have died. You may feel yourself slipping away, but it isn’t as though there will be a “you” around who is capable of ascertaining that, once all is said and done, it has actually happened. Just to remind you, you need a working cerebral cortex to harbor propositional knowledge of any sort, including the fact that you’ve died—and once you’ve died your brain is about as phenomenally generative as a head of lettuce. In a 2007 article published in the journal Synthese, University of Arizona philosopher Shaun Nichols puts it this way: “When I try to imagine my own non-existence I have to imagine that I perceive or know about my non-existence. No wonder there’s an obstacle!”

Scientists watch evolution unfold

Time in a bottle: Scientists watch evolution unfold

Lenski, Hannah Professor of Microbial Ecology at MSU, started growing cultures of fast-reproducing, single-celled E. coli bacteria in 1988. If a genetic mutation gives a cell an advantage in competition for food, he reasoned, it should dominate the entire culture. While Darwin’s theory of natural selection is supported by other studies, it has never before been studied for so many cycles and in such detail.

“It’s extra nice now to be able to show precisely how selection has changed the genomes of these bacteria, step by step over tens of thousands of generations,” Lenski said.

Lenski’s team periodically froze bacteria for later study, and technology has since developed to allow complete genetic sequencing. By the 20,000-generation midpoint, researchers discovered 45 mutations among surviving cells. Those mutations, according to Darwin’s theory, should have conferred some advantage, and that’s exactly what the researchers found.

How life evolved: 10 steps to the first cells

How life evolved: 10 steps to the first cells – 14 October 2009 – New Scientist

We may never be able to prove beyond any doubt how life first evolved. But of the many explanations proposed, one stands out – the idea that life evolved in hydrothermal vents deep under the sea. Not in the superhot black smokersMovie Camera, but more placid affairs known as alkaline hydrothermal vents.

This theory can explain life’s strangest feature, and there is growing evidence to support it.

Earlier this year, for instance, lab experiments confirmed that conditions in some of the numerous pores within the vents can lead to high concentrations of large molecules. This makes the vents an ideal setting for the “RNA world” widely thought to have preceded the first cells.

If life did evolve in alkaline hydrothermal vents, it might have happened something like this:
1.

Water percolated down into newly formed rock under the seafloor, where it reacted with minerals such as olivine, producing a warm alkaline fluid rich in hydrogen, sulphides and other chemicals – a process called serpentinisation.

This hot fluid welled up at alkaline hydrothermal vents like those at the Lost City, a vent system discovered near the Mid-Atlantic Ridge in 2000.
2.

Unlike today’s seas, the early ocean was acidic and rich in dissolved iron. When upwelling hydrothermal fluids reacted with this primordial seawater, they produced carbonate rocks riddled with tiny pores and a “foam” of iron-sulphur bubbles.
3.

Inside the iron-sulphur bubbles, hydrogen reacted with carbon dioxide, forming simple organic molecules such as methane, formate and acetate. Some of these reactions were catalysed by the iron-sulphur minerals. Similar iron-sulphur catalysts are still found at the heart of many proteins today.
4.

The electrochemical gradient between the alkaline vent fluid and the acidic seawater leads to the spontaneous formation of acetyl phosphate and pyrophospate, which act just like adenosine triphosphate or ATP, the chemical that powers living cells.

These molecules drove the formation of amino acids – the building blocks of proteins – and nucleotides, the building blocks for RNA and DNA.
5.

Thermal currents and diffusion within the vent pores concentrated larger molecules like nucleotides, driving the formation of RNA and DNA – and providing an ideal setting for their evolution into the world of DNA and proteins. Evolution got under way, with sets of molecules capable of producing more of themselves starting to dominate.
6.

Fatty molecules coated the iron-sulphur froth and spontaneously formed cell-like bubbles. Some of these bubbles would have enclosed self-replicating sets of molecules – the first organic cells. The earliest protocells may have been elusive entities, though, often dissolving and reforming as they circulated within the vents.
7.

The evolution of an enzyme called pyrophosphatase, which catalyses the production of pyrophosphate, allowed the protocells to extract more energy from the gradient between the alkaline vent fluid and the acidic ocean. This ancient enzyme is still found in many bacteria and archaea, the first two branches on the tree of life.
8.

Some protocells started using ATP as well as acetyl phosphate and pyrophosphate. The production of ATP using energy from the electrochemical gradient is perfected with the evolution of the enzyme ATP synthase, found within all life today.
9.

Protocells further from the main vent axis, where the natural electrochemical gradient is weaker, started to generate their own gradient by pumping protons across their membranes, using the energy released when carbon dioxide reacts with hydrogen.

This reaction yields only a small amount of energy, not enough to make ATP. By repeating the reaction and storing the energy in the form of an electrochemical gradient, however, protocells “saved up” enough energy for ATP production.
10.

Once protocells could generate their own electrochemical gradient, they were no longer tied to the vents. Cells left the vents on two separate occasions, with one exodus giving rise to bacteria and the other to archaea.

Was our oldest ancestor a proton-powered rock?

Was our oldest ancestor a proton-powered rock? – life – 19 October 2009 – New Scientist

The picture painted by Russell and Martin is striking indeed. The last common ancestor of all life was not a free-living cell at all, but a porous rock riddled with bubbly iron-sulphur membranes that catalysed primordial biochemical reactions. Powered by hydrogen and proton gradients, this natural flow reactor filled up with organic chemicals, giving rise to proto-life that eventually broke out as the first living cells – not once but twice, giving rise to the bacteria and the archaea.

Many details have yet to be filled in, and it may never be possible to prove beyond any doubt that life evolved by this mechanism. The evidence, however, is growing. This scenario matches the known properties of all life on Earth, is energetically plausible – and returns Mitchell’s great theory to its rightful place at the very centre of biology.

Darwinopterus: New flying dinosaur discovered that could fill evolutionary gap

Darwinopterus: New flying dinosaur discovered that could fill evolutionary gap | Mail Online

The discovery is believed to fill the evolutionary gap between two types of pterosaurs – primitive long-tailed forms and their descendants, advanced short-tailed pterosaurs, some of which reached gigantic size.

The researchers said the groups were separated by a large evolutionary gap, identified in Charles Darwin’s time, which looked as if it would never be filled – until now.