Saturday, October 17, 2009

10/17/09 President Barack Obama Weekly Radio Address

SATURDAY, OCTOBER 17TH, 2009 AT 12:01 AM
Weekly Address: Taking the Insurance Companies on Down the Stretch
Posted by Jesse Lee
As the health insurance reform debate enters into its final stages in Congress, the President denounces the desperate and deceptive last-ditch efforts of the health insurance companies to derail it.


read the transcript

THE WHITE HOUSE


Office of the Press Secretary

________________________________________________
For Immediate Release            October 17, 2009

WEEKLY ADDRESS: President Obama Calls Hails Progress on Health Insurance Reform Despite Defenders of the Status Quo
WASHINGTON – In his weekly address, President Barack Obama praised the progress that has been made on health insurance reform, and spoke out against those who defend the status quo in order to score political points and protect their profits.  With reform the closest it has ever been to becoming law, the insurance companies are rolling out deceptive ads, paying for misleading studies, and flooding Capitol Hill with lobbyists.  Now, Washington needs to serve the American people, not the special interests.






  October 17, 2009 , 10:44 am

The Saturday Word: Health Care Battles

"President Obama defended his health care overhaul against the health insurers with renewed gusto Saturday morning after a week in which insurance companies circulated reports and ran advertisements deeply critical of his plans.

“They’re filling the airwaves with deceptive and dishonest ads. They’re flooding Capitol Hill with lobbyists and campaign contributions. And they’re funding studies designed to mislead the American people,” Mr. Obama said adding firepower to Congressional Democrats’ already hostile responses. “It’s smoke and mirrors. It’s bogus. And it’s all too familiar. Every time we get close to passing reform, the insurance companies produce these phony studies as a prescription and say, “Take one of these, and call us in a decade.”

"His comments were the latest sign that the relationship between insurance companies and the administration has deteriorated after months of cooperation.

"On Friday the White House backed away from restrictions laid in September that prohibited insurance companies from warning Medicare recipients of potential cuts to their program in the health care overhaul. The administration also cited one company in particular, Humana, for violating Medicare rules, saying the company had misled its beneficiaries to derail the plan."

Obama Chastises "Dishonest" Health Insurers
Published: October 17, 2009

 WASHINGTON (Reuters) - "U.S. President Barack Obama lashed out on Saturday against the "deceptive and dishonest" efforts of health insurance companies, who he said are trying to kill healthcare reform, no matter the cost to the country.

The Democratic president's push to overhaul the $2.5 trillion (1.528 trillion pound) U.S. healthcare industry, his top domestic policy priority, received a big boost this week when the Senate Finance Committee approved its version of a reform measure with the support of Republican Senator Olympia Snowe.

"Many experts expect some version of a healthcare bill will pass this year, but there are still major disagreements on details including whether the measure will include a government-run insurance program, the "public option."

"For the first time ever, all five committees in Congress responsible for health reform have passed a version of legislation," Obama said in his weekly radio address. "As I speak to you today, we are closer to reforming the health care system than we have ever been in history."

"However, he acknowledged the overhaul still must clear significant hurdles before becoming law. "And there are still those who would try to kill reform at any cost," he said.

"The history is clear: for decades rising health care costs have unleashed havoc on families, businesses and the economy. And for decades, whenever we have tried to reform the system, the insurance companies have done everything in their considerable power to stop us."

BATTLE LEAPED IN INTENSITY THIS WEEK

"The battle over reform between angry Democrats and health insurers leaped in intensity when the industry trade group America's Health Insurance Plans issued a report on Monday, on the eve of the finance committee's vote, saying Senate healthcare legislation would lead to increases in annual insurance premiums of as much as $4,000 by 2019.

"Democrats denied the findings, citing a report by the nonpartisan Congressional Budget Office that said the Finance Committee bill would make health coverage affordable to millions of Americans who do not have it and slow the growth of healthcare costs.

"In fact, the insurance industry is rolling out the big guns and breaking open their massive war chest -- to marshal their forces for one last fight to save the status quo," Obama said.

"They're filling the airwaves with deceptive and dishonest ads. They're flooding Capitol Hill with lobbyists and campaign contributions. And they're funding studies designed to mislead the American people," he said.

Democratic leaders in Congress began work this week on merging the various committees' proposals on healthcare while keeping party liberals and moderates -- and Snowe -- happy.

"Senate Republicans demanded Democrats allow more time to debate the details of the sweeping plan. Obama has set the end of the year as his goal for passing a measure that would begin to slow increases in healthcare costs, regulate the insurance market and expand health coverage without increasing the federal budget deficit.

"Health insurers' shares dropped this week after news of the finance committee's vote.

"Obama vowed an overhaul will go through.

"Every time we get close to passing reform, the insurance companies produce these phony studies as a prescription and say, 'Take one of these, and call us in a decade.' Well, not this time," Obama said.

(Editing by Todd Eastham)

Obama Praises Senate Committee's Health Care Vote

By THE ASSOCIATED PRESS 
Published: October 17, 2009 
 
 
 WASHINGTON (AP) -- "Pushing back against his critics, President Barack Obama says overhauling the health care system, while helping millions of people, also will test whether policy makers can ''serve the national interest despite the unrelenting efforts of the special interests.''

"The administration is trying to build momentum for the president's overhaul effort after the Senate Finance Committee voted 14-9 this week for a bill that would extend health care coverage to millions of people. One Republican, Maine Sen. Olympia Snowe, supported the bill, and the measure faces considerable opposition from the health care industry, labor unions and large business organizations.

''The history is clear: For decades rising health care costs have unleashed havoc on families, businesses and the economy,'' the president said Saturday in his weekly radio and Internet address. ''And for decades, whenever we have tried to reform the system, the insurance companies have done everything in their considerable power to stop us.''

"The health insurance industry released a study earlier this week concluding that the Finance Committee bill -- one of five competing House and Senate health care measures -- would raise premiums significantly for millions of people who already have health coverage.

"The report drew intense criticism from the White House, congressional Democrats and other advocates of the bill who deemed the study a last-ditch effort to sway public opinion against the measure.

"Obama said he would not abide ''those who would bend the truth or break it to score political points and stop our progress as a country.'' He accused the industry of ''filling the airwaves with deceptive and dishonest ads,'' sending money and lobbyists to Capitol Hill and paying for studies ''designed to mislead the American people.''

"The insurance industry responded Saturday, saying it supports a comprehensive, bipartisan overhaul of the system but that separate studies recently found that some of the existing proposals will increase significantly health care costs for families and employers.

''Reform needs to work and deliver on the promise made to the American people that everyone will have quality, affordable coverage,'' Karen Ignagni, president of the industry group America's Health Insurance Plans, said in a statement.

"The bills moving through Congress generally would require most Americans to buy insurance, provide federal subsidies to help lower-income people afford coverage and help small businesses defray the cost of extending coverage to their workers.

"The measures would bar insurers from denying coverage because of pre-existing medical conditions and limit their ability to charge higher premiums based on age or family size. Expanded coverage would be paid for by cutting hundreds of billions of dollars from future Medicare payments to health care providers. Higher taxes also are included in the bills.

"Republican opponents say the bills will increase costs for patients, further job losses and give the government more of a say in who gets medical care, and what kind.

''Americans inherently know government interference drives costs up, not down,'' Rep. Kevin Brady, R-Texas, said in the GOP's weekly message. ''The massive health care plans being crafted behind closed doors in Washington will ultimately allow the government to decide what doctors we can see, what treatments the government thinks you deserve and what medicines you can receive.''

 
                                                                                                                                                                                                          White House Photo, Pete Souza_10-17-09

Friday, October 16, 2009

Researchers Investigate the Connection Between the Diminishment of Biodiversity and the Weakening of Global Economic Development


Yellow banded dart frog. Amphibians are facing some of the worst threats to their biodiversity. A report in the journal Science highlights how biodiversity loss is weakening efforts to tackle global poverty.


PHYSORG.COM writes: "Biodiversity loss is undermining global development, leading scientists warn. The paper brings together a broad group of scientists and policy makers, including Natural History Museum plant expert Dr Sandra Knapp."

Global economic development is being threatened by the sustained loss of biodiversity according to a group of respected scientists: Jeffrey D. Sachs, Jonathan E. M. Baillie, William J. Sutherland, Paul R. Armsworth, Neville Ash, John Beddington, Tim M. Blackburn, Ben Collen, Barry Gardiner, Kevin J. Gaston, H. Charles J. Godfray, Rhys E. Green, Paul H. Harvey, Brett House, Sandra Knapp, Noëlle F. Kümpel, David W. Macdonald, Georgina M. Mace, James Mallet, Adam Matthews, Robert M. May, Owen Petchey, Andy Purvis, Dilys Roe, Kamran Safi, Kerry Turner Matt Walpole, Robert Watson, Kate E. Jones who published an article, "Biodiversity Conservation and the Millennium Development Goals," to publish their findings in the September 18, 2009 issue of Science.

The summary that appears in Science condenses the main thrust of the collaborative article: "The Millennium Development Goals (MDGs) are designed to inspire efforts to improve people's lives by, among other priorities, halving extreme poverty by 2015 (1). Analogously, concern about global decline in biodiversity and degradation of ecosystem services (2) gave rise in 1992 to the Convention on Biological Diversity (CBD). The CBD target "to achieve by 2010 a significant reduction of the current rate of biodiversity loss" was incorporated into the MDGs in 2002. Our lack of progress toward the 2010 target (3, 4) could undermine achievement of the MDGs and poverty reduction in the long term. With increasing global challenges, such as population growth, climate change, and overconsumption of ecosystem services, we need further integration of the poverty alleviation and biodiversity conservation agendas."

The main thrust of the article argues that "Biodiversity loss is undermining global development."

The authors of the article explain that: "Goals set to alleviate extreme poverty will not be met unless we address the accelerating rate of biodiversity loss,.., and new achievable targets are needed urgently."

The authors of the study contend that: "Poverty and environmental degradation have many of the same fundamental causes, such as the pressures of unsustainable human population growth."

The group of authors are in accord that: "More research is needed into the links between biodiversity and poverty, the team says, so that better decisions can be made about how the environment is used in future. The outcomes should benefit both poverty alleviation and conservation."

‘Degradation of the natural diversity of our planet will inevitably bring problems for our own species,’ says Dr Sandra Knapp.

Dr Knapp explains, ‘The integration of conservation and development goals will be difficult, and will require new interactions between scientific communities and with the public at large’.

‘We hope the newly opened Darwin Centre at the Natural History Museum can be a focal point for discussion of issues that confront all of us as we integrate the Millennium Development Goals with our concern for the natural world,’ Dr Knapp concluded.

PHYSORG.COM explains that: "The 8 Millennium Development Goals were agreed by all the world’s countries and one of the goals is to halve extreme poverty by 2015. The Convention on Biological Diversity, signed by 150 governments at the 1992 Rio Earth Summit, is dedicated to promoting sustainable development. However, the goals of both of these will not be met unless humans begin living in a more sustainable way."

Dr Kate Jones, Senior Research Fellow at ZSL concludes: ‘The global issues are now so intense we will only succeed if we have an integrated environment and development agenda - our children’s environment is an essential part of their welfare.’


Provided by American Museum of Natural History (news : web)


Global development and biodiversity

Thursday, October 15, 2009

Scientists Feel Confident That They Have Finally determined that the flatworm Acoelomorpha Belongs as a Sister Clade to Other Bilateral Animals


An international research team led by Brown University has determined that the flatworm Acoelomorpha belongs as a sister clade to other bilateral animals. The finding means the worm is a product of the deepest split within the bilateral animals, the first evolutionary divergence within the group. 
Credit: Eric Rottinger/Kahikai.org

An article in PHYSORG.COM explains: "When it comes to understanding a critical junction in animal evolution, some short, simple flatworms have been a real thorn in scientists' sides. Specialists have jousted over the proper taxonomic placement of a group of worms called Acoelomorpha. This collection of worms, which comprises roughly 350 species, is part of a much larger group called bilateral animals, organisms that have symmetrical body forms, including humans, insects and worms. The question about acoelomorpha, was: Where do they fit in?"

Acoelomorpha, the most primitive bilateral animals, has held the fascination of researchers for a number of years. It as been referred to as an "enigmatic,... rogue animal,." As it has been studied: "It has been wandering throughout the animal tree of life," said Casey Dunn, an evolutionary biologist at Brown University. Acoelomorpha are "tiny, cryptic worms that many consider to be the most primitive of all bilaterally symmetrical animals."

  
Acoelomorpha, a tiny, primitive flatworm



The reason why Acoelomorpha are a disputed phylum of animals with planula-like features (free-swimming or crawling larval type common in many species of the phylum Cnidaria (e.g., jellyfish, corals, and sea anemones). The Acoelomorpha has recently been classified by Jaume Baguñà and Marta Riutort as a separate phylum, basal, forming a basis; fundamental; basic form among the Bilateria."There are two or more superphyla (main lineages) of Bilateria" including ... "the protostomes (which) include most of the rest, such as arthropods, annelids, mollusks, flatworms, and so forth.... There are a number of differences, most notably in how the embryo develops. In particular, the first opening of the embryo becomes the mouth in protostomes."



Acoelomorpha are very primitive flatworms

PHYSORG.COM explains: "The worm wanders no more. Through a laborious genetic sequencing analysis, Dunn and an international team of scientists have settled the long-standing debate and determined that acoelomorpha belongs as a sister clade to other bilateral animals. The finding is significant, Dunn said, because it shows the worm is a product of the deepest split within the bilateral animals, the first evolutionary divergence within the group. Because of that, scientists have gained a key insight into the most recent common ancestor to bilaterians, a species that remains unknown.

The flatworm is "as distant as an animal can be in bilateria and still be a bilaterian," said Dunn, "So, now we have two perspectives to (find out about) this common ancestor, the acoelomorphs and all the other bilateral animals."


A team of 17 scientists from the United States, France Germany, Sweden, Spain and the United Kingdom, published the results of their research recently in the Proceedings of the Royal Society B, and produced two interesting findings that stood out:

"The debate appears to be over for Xenoturbella, a type of marine worm whose ancestral affiliation had been tossed between worms and mollusks. The researchers reported their genetic analysis shows diminishing evidence for placing xenoturbella within Deuterostomia, one of the major groups within the animal kingdom. Coincidentally, it also shows that xenoturbella may be a close relative to acoelomorpha.
"Cycliophora, a single species discovered in 1994 that lives on the bristles surrounding the mouth of the Norway lobster Nephrops norvegicus, has found a home with Entoprocta and Ectoprocta. The researchers base their findings on an analysis that reached further into the genetic makeup of cycliophora than previous studies had done."
"The team used a genetic sequencing technique called expressed sequence tags to carry out the phylogenetic studies. The aim of this approach, discussed in a study led by Dunn that appeared in Nature last year, is to analyze a large number of genes from a large number of animals. For this paper, the researchers looked at 1,487 genes, a 10-fold increase in the number of genes analyzed in previous studies. In all, the researchers logged 2.25 million processor hours on a supercomputer in California to obtain the results. Dunn called the effort the most computationally intensive phylogenetic analysis to date."


A color enhanced photo of the primitive flatworm Acoelomorpha

Wednesday, October 14, 2009

A Thick, Misty Haze of Organically Rich Compounds Filled the Atmosphere of a Young Earth and Contributed to the Development of Terrestrial Life Forms on the Surface of our Home Planet


The photochemistry of methane and carbon dioxide may have produced an organic haze layer on early Earth.. Credit: NASA

Anuradha K. Herath of PHYSORG.COM summarizes the view that: "Haze in the early Earth atmosphere could have played a crucial role in the origin of life. By forming a protective shield, the haze would have safeguarded organic substances from harmful ultraviolet (UV) radiation."

H. Langley DeWitt of the Department of Chemistry and Biochemistry at the University of Colorado at Boulder, adds his conjecture that "Knowing more about the atmospheric conditions right before life began to develop could give researchers clues to how exactly life developed.”

There was a global blanketing of organic haze across the young planet Earth according to a group of research scientists led by H. Langley DeWitt.

"Haze is produced when sunlight comes in contact with certain gases in the atmosphere," Herath explained. "The types of aerosols formed through this photochemical reaction depend on the specific composition of the atmosphere.

"The amount and the composition of the haze would determine whether it produced a warming or cooling effect for the planet. This new study shows that the amount of haze on early Earth was inadequate to have the type of cooling effect that scientists had previously predicted.The amount and the composition of the haze would determine whether it produced a warming or cooling effect for the planet. This new study shows that the amount of haze on early Earth was inadequate to have the type of cooling effect that scientists had previously predicted," concluded Herath.

Two other scientists; Armen Mulkidjanian of the University of Osnabrueck, Germany and Michael Galperin of the U.S. National Institutes of Health have advanced their view: "that life on Earth originated at photosynthetically-active porous structures, similar to deep-sea hydrothermal vents, made of zinc sulfide (more commonly known as phosphor). They argue that under the high pressure of a carbon-dioxide-dominated atmosphere, zinc sulfide structures could form on the surface of the first continents, where they had access to sunlight. Unlike many existing theories that suggest UV radiation was a hindrance to the development of life, Mulkidjanian and Galperin think it actually helped.

“The problem of the origin of life is such that you have to answer a set of different questions to explain how life has originated,” says lead author Mulkidjanian. “We just provide answers to the problem of energetics of the origin of life.”

Most scientists agree today that the atmosphere primarily originated from the accumulation of carbon dioxide mixed with smaller amounts of other gases. Living organisms originated by using some form of energy flow—solar radiation or chemical reactions to contribute to the development of life has also led some researchers to the conjecture that "zinc sulfide may have played a major role in the development of life" on Earth.."Its ability to store light makes zinc sulfide an important factor in the discussion on life’s origin." Mulkidjanian explains that, "once illuminated by UV light, zinc sulfide can efficiently reduce carbon dioxide, just as plants do."

Mulkidjanian and Galperin "suggest that life on Earth originated at photosynthetically-active porous structures, similar to deep-sea hydrothermal vents, made of zinc sulfide (more commonly known as phosphor). They argue that under the high pressure of a carbon-dioxide-dominated atmosphere, zinc sulfide structures could form on the surface of the first continents, where they had access to sunlight. Unlike many existing theories that suggest UV radiation was a hindrance to the development of life, Mulkidjanian and Galperin think it actually helped.

“The problem of the origin of life is such that you have to answer a set of different questions to explain how life has originated,” says lead author Mulkidjanian. “We just provide answers to the problem of energetics of the origin of life.”

"Included in these recent theories concerning the developments of terrestrial life is the proposal "that there was plate-tectonic activity in the first 500 million years of Earth's history," said geochemistry professor Mark Harrison, director of UCLA's Institute of Geophysics and Planetary Physics and co-author of the Nature paper. "We are reporting the first evidence of this phenomenon."

"Unlike the longstanding myth of a hellish, dry, desolate early Earth with no continents, it looks like as soon as the Earth formed, it fell into the same dynamic regime that continues today," Harrison said. "Plate tectonics was inevitable, life was inevitable. In the early Earth, there appear to have been oceans; there could have been life — completely contradictory to the cartoonish story we had been telling ourselves."

"We're revealing a new picture of what the early Earth might have looked like," said lead author Michelle Hopkins, a UCLA graduate student in Earth and space sciences. "In high school, we are taught to see the Earth as a red, hellish, molten-lava Earth. Now we're seeing a new picture, more like today, with continents, water, blue sky, blue ocean, much earlier than we thought."

"The research by Harrison, Hopkins and Craig Manning, a UCLA professor of geology and geochemistry, is based on their analysis of ancient mineral grains known as zircons found inside molten rocks, or magmas, from Western Australia that are about 3 billion years old. Zircons are heavy, durable minerals related to the synthetic cubic zirconium used for imitation diamonds and costume jewelry. The zircons studied in the Australian rocks are about twice the thickness of a human hair.

"... Analysis determined that some of the zircons found in the magmas were more than 4 billion years old. They were also found to have been formed in a region with heat flow far lower than the global average at that time.

"The global average heat flow in the Earth's first 500 million years was thought to be about 200 to 300 milliwatts per meter squared," Hopkins said. "Our zircons are indicating a heat flow of just 75 milliwatts per meter squared — the figure one would expect to find in subduction zones, where two plates converge, with one moving underneath the other."

"The data we are reporting are from zircons from between 4 billion and 4.2 billion years ago," Harrison said. "The evidence is indirect, but strong. We have assessed dozens of scenarios trying to imagine how to create magmas in a heat flow as low as we have found without plate tectonics, and nothing works; none of them explain the chemistry of the inclusions or the low melting temperature of the granites."

"Evidence for water on Earth during the planet's first 500 million years is now overwhelming, according to Harrison.

"You don't have plate tectonics on a dry planet," he said.

"Strong evidence for liquid water at or near the Earth's surface 4.3 billion years ago was presented by Harrison and colleagues in a Jan. 11, 2001, cover story in Nature.

"Five different lines of evidence now support that once radical hypothesis," Harrison said. "The inclusions we found tell us the zircons grew in water-saturated magmas. We now observe a surprisingly low geothermal gradient, a low rate at which temperature increases in the Earth. The only mechanism that we recognize that is consistent with everything we see is that the formation of these zircons was at a plate-tectonic boundary. In addition, the chemistry of the inclusions in the zircons is characteristic of the two kinds of magmas today that we see at place-tectonic boundaries."

"We developed the view that plate tectonics was impossible in the early Earth," Harrison added. "We have now made observations from the Hadean (the Earth's earliest geological eon) — these little grains contain a record about the conditions under which they formed — and the zircons are telling us that they formed in a region with anomalously low heat flow. Where in the modern Earth do you have heat flow that is one-third of the global average, which is what we found in the zircons? There is only one place where you have heat flow that low in which magmas are forming: convergent plate-tectonic boundaries."

"Three years ago, Harrison and his colleagues applied a technique to determine the temperature of ancient zircons.

"We discovered the temperature at which these zircons formed was constant and very low," Harrison said. "You can't make a magma at any lower temperature than what we're seeing in these zircons. You look at artists' conceptions of the early Earth, with flying objects from outer space making large craters; that should make zircons hundreds of degrees centigrade hotter than the ones we see. The only way you can make zircons at the low temperature we see is if the melt is water-saturated. There had to be abundant water. That's a big surprise because our longstanding conception of the early Earth is that it was dry."

"Scientists have looked to Titan, Saturn’s largest moon," Herath explained, "to try to better understand the organic haze that may have existed on early Earth. Titan has a thick atmosphere containing 95 percent nitrogen, three percent methane and two percent of hydrogen and other hydrocarbons, and an atmospheric pressure about 1.6 times that of Earth. Titan is also the only planetary body other than Earth with surface liquid (on Earth that surface liquid is water, while on Titan the surface liquid is ethane and methane.)

"In a 2006 NASA study, a group of researchers that included DeWitt replicated the atmospheres of Titan and early Earth. They then compared the aerosols produced in the laboratory to the haze observed in Titan’s atmosphere during NASA’s Cassini mission. The group concluded that the two atmospheres were similar.

"But there was one troubling result. An important distinction between the atmospheres of Titan and Earth is the carbon dioxide that is present in the Earth’s atmosphere. The laboratory results in the 2006 study suggested that the reaction of carbon dioxide and methane would produce more haze on early Earth than the amount found on Titan. That implies that the Earth would have been subjected to a large anti-greenhouse or cooling effect.

"The current study puts that concern to rest. DeWitt and her colleagues did additional laboratory experiments that expanded upon the 2006 study. They added hydrogen to the atmospheric composition and found that it reduced aerosol formation to the point where any potential anti-greenhouse effect would be negligible.


A colorized image of Titan’s haze taken during the Cassini mission. Credit: NASA/JPL/Space Science Institute

"DeWitt’s team also looked at how varying quantities of the three main substances—hydrogen, methane and carbon dioxide—may have affected the haze that formed on Earth billions of years ago.

“Many models calculate the amount of haze that would be present at the different ratios of these chemicals,” DeWitt explains. “However, the models don’t always include experimental data in their calculations and instead use assumptions about the chemistry.”

"The new study used a simplified version of an atmospheric model to examine two scenarios. One mixture contained high quantities of hydrogen and carbon dioxide with low amounts of methane. In the second simulation, the team analyzed the effects of hydrogen in a mixture that contained high amounts of methane. After the gas mixtures were exposed to UV radiation, the scientists measured the aerosols that were formed.

"Their findings showed that an increase in hydrogen levels reduced the haze formation rate. They also concluded that the amount of hydrogen present in the early Earth atmosphere most likely resulted in warmer surface temperatures.

“If an organic haze did form on early Earth, the consequences of its presence beg all sorts of interesting questions,” says co-author Christa Hasenkopf of the Cooperative Institute for Research in Environmental Sciences, also at the University of Colorado at Boulder.

"A question for astrobiologists is what role haze would have played in the formation of life. The scientists stated that the aerosols produced on early Earth provided a major source of organic substances to the Earth’s surface. Scientists think these organics played an important role in the origin of life on our planet. Understanding the characteristics of haze that make a planet’s surface ripe for organic material could be immensely helpful in the quest for life on other planetary bodies.

"Hasenkopf says some scientists believe that the early Earth atmosphere was “virtually oxygen-free when life first formed.” That allows astrobiologists to think more broadly about what types of environments on other planets could possibly support life.

“We only know of one place in the entire universe that life was able to initially form and develop, and that was on the early Earth,” says Hasenkopf. “The climactic conditions on early Earth provide clues to our own origins.”

"Scientists don’t know enough about our planet’s environment approximately four billion years ago to be able to precisely mimic the atmospheric conditions back then. The laboratory re-creation of early Earth therefore was based on many assumptions.

"The study model used simplified calculations for determining surface temperature, and the chemical reactions were based on shorter reaction times than what would have occurred under actual conditions. Additionally, the researchers only focused on three gases: methane, carbon dioxide and hydrogen. While these are believed to be the major constituents of the early Earth atmosphere, there could have been other components, such as sulfur dioxide, which were not taken into account in this study. Still, DeWitt says their study could improve the accuracy of models that predict chemical reactions in the atmosphere.

"Hasenkopf says the findings also can contribute to the understanding of the current effects of climate change.

"Some scientists believe that the early Earth atmosphere contained higher levels of carbon dioxide and methane than current atmospheric levels. Hasenkopf explains that the interaction between the gases that produce greenhouse warming and the haze that brings about the anti-greenhouse cooling is similar to the present-day emissions caused by human activity.

“On one hand, humans emit greenhouse gases, such as carbon dioxide, causing warming,” Hasenkopf says. “Yet humans also emit large amounts of particulate pollution, which may have a net cooling effect, similar to the early Earth haze.”

Tuesday, October 13, 2009

Recent Research in Humanity's Migration Out of Africa Took Place More Recently Than Previously Believed


Humans spread out of Africa later
Modern humans spread out of Africa 20,000 years later than previously thought, according to new genetic research just published. Detailed world map showing directions and times of major migration of modern humans. New research shows they spread out of Africa 20,000 years later than previously thought at around 55-60,000 years ago.
© Trends in Ecology & Evolution

Research scientists are constantly developing new approaches to developing innovative methods  to examine information obtained from mitochondrial DNA (mtDNA). Professor Chris Stringer has been studying the various methods scientists use to determine chronologies for important points in human evolutionary history.

"Mitochondria are the tiny structures in each human cell that produce the cell’s power. They contain their own DNA and this is inherited through the mother."

‘We tried alternative ways to date recent episodes in human evolution, such as our split from Neanderthals, and we found these events occurred more recently in time,’ says Prof Stringer.

It is now believed that modern humans and Neanderthals underwent a species separation approximately 300-400,000 years ago; this is much earlier than the previously accepted era 500-600,000 years ago.

It is believed that: "modern humans migrated out of Africa between 55-60,000 years ago rather than the previous dates of 70-80,000 years."

Researchers have also ascertained "more recent dates for other crucial events such as the age of our African ancestral mother, known as mitochondrial Eve, from who all recent humans (Homo sapiens) descended. She was found to have lived around 110-130,000 years ago, rather than previous estimates of 150,000-200,000 years ago.

‘The new dates are consistent with the most recent fossil and archaeological data for Neanderthal evolution, our exit from Africa and our arrival in Asia, Australia, Europe and the Americas,’ says Prof Stringer.

‘And they also cast doubt on ideas of an early exit from Africa towards China and Australia.’

Sources: PHYSORG.COM; Chris Stringer, Phillip Endicott, Simon Y.W. Ho, and Mait Metspalu's Evaluating the Mitochondrial Timescale of Human Evolution paper is published in the journal Trends in Ecology and Evolution; American Museum of Natural History (news : web)