Science Headlines for November 20, 2008

Mysterious Source Of High-Energy Cosmic Radiation Discovered: Nearby Exotic Object?

Scientists have discovered a previously unidentified nearby source of high-energy cosmic rays. The finding was made with a NASA-funded balloon-borne instrument high over Antarctica.
Source: ScienceDaily: Latest Science News | 20 Nov 2008 | 7:00 pm

Physicist Make Droplets Dance Above A Surface

Physicists can now make droplets dance, float and bounce above a surface, keeping small amounts of fluid free of contamination and ripe for testing.
Source: ScienceDaily: Latest Science News | 20 Nov 2008 | 7:00 pm

New Platinum-phosphate Compounds Kill Ovarian Cancer Cells, Other Cancer Cells

A new class of compounds called phosphaplatins can effectively kill ovarian, testicular, head and neck cancer cells with potentially less toxicity than conventional drugs, according to a new study in the journal Proceedings of the National Academy of Sciences.
Source: ScienceDaily: Latest Science News | 20 Nov 2008 | 7:00 pm

Drug-related Preference In Cocaine Addiction Extends To Images

When given a choice between viewing pictures of cocaine and a variety of other images, cocaine addicted individuals, as compared to healthy, non-addicted research subjects, show a clear preference for the drug-related images.
Source: ScienceDaily: Latest Science News | 20 Nov 2008 | 7:00 pm

New Gene-silencing Pathway Found In Plants

Biologists have made major headway in explaining a mechanism by which plant cells silence potentially harmful genes. New research in Cell explains how RNA polymerases work together to use the non-coding region of DNA to prevent destructive, virus-derived genes from being activated. This research adds to a growing body of evidence suggesting that "junk DNA" is in fact a functional part of the genome, since transcription of the intergenic regions is necessary to keep potentially harmful genes turned off.
Source: ScienceDaily: Latest Science News | 20 Nov 2008 | 7:00 pm

Genome-wide Association Scan For Genetic Determinants Of Warfarin Dose

A growing number of geneticists are using genome-wide association studies (GWAS) to systematically search for and identify single nucleotide polymorphisms (SNPs), which are single base changes in the human DNA sequence that can cause differences in genetic characteristics. GWAS may also detect genes that are associated with a particular health condition, or with variation in patient response to prescribed drugs.
Source: ScienceDaily: Latest Science News | 20 Nov 2008 | 7:00 pm

Turtles Alter Nesting Dates Due To Temperature Change

Researchers say turtles nesting along the Mississippi River and other areas are altering their nesting dates in response to rising temperatures.
Source: ScienceDaily: Latest Science News | 20 Nov 2008 | 4:00 pm

Enzyme Discovery May Lead To Better Heart And Stroke Treatments

A new study sheds new light on the way one of our cell enzymes, implicated in causing tissue damage after heart attacks and strokes, is normally kept under control.
Source: ScienceDaily: Latest Science News | 20 Nov 2008 | 4:00 pm

Exercise Is Safe, Improves Outcomes For Patients With Heart Failure, Study Suggests

Working out on a stationary bicycle or walking on a treadmill just 25 to 30 minutes most days of the week is enough to modestly lower risk of hospitalization or death for patients with heart failure, say researchers.
Source: ScienceDaily: Latest Science News | 20 Nov 2008 | 4:00 pm

Woolly-mammoth Genome Sequenced

Scientists have completed the genome-wide sequence of an extinct animal. The scientists sequenced the genome of the woolly mammoth, an extinct species of elephant that was adapted to living in the cold environment of the northern hemisphere. They sequenced four billion DNA bases using next-generation DNA-sequencing instruments and a novel approach that reads ancient DNA highly efficiently.
Source: ScienceDaily: Latest Science News | 20 Nov 2008 | 4:00 pm

Razib Khan: Polygamy may be the natural, though unfair, order of things

Razib Khan: Some religions accept polygamy; others abhor it. But in nature, it's often a case of winner-takes-all-the-wives
Source: Science | guardian.co.uk | 20 Nov 2008 | 12:00 pm

Dems look to stop endangered species rule changes (AP)

AP - With the Bush administration on the verge of relaxing regulations protecting endangered species, Democratic leaders are looking at ways to overturn any last-minute rule changes.

Source: Yahoo! News: Science News | 20 Nov 2008 | 11:57 am

Home from home

International Space Station marks its tenth anniversary
Source: BBC News | Science & Environment | UK Edition | 20 Nov 2008 | 11:49 am

Slow progress on ocean protection

Two year after pledging to protect 10% of the oceans, governments have protected less than 1%, a survey finds.
Source: BBC News | Science & Environment | UK Edition | 20 Nov 2008 | 11:11 am

Invasive mussel confirmed in Utah's Electric Lake (AP)

AP - Trouble-making zebra mussels have arrived in Utah. But not where they were expected to show up.

Source: Yahoo! News: Science News | 20 Nov 2008 | 11:03 am

Astronauts vow remaining tool bag won't drift away (AP)

AP - Astronauts vowed to double-check, even triple-check, to make sure a bag of tools is properly tied down during a spacewalk Thursday so it doesn't float away like one did earlier this week.

Source: Yahoo! News: Science News | 20 Nov 2008 | 10:59 am

Adam Rutherford: Bringing back the woolly mammoth must remain the stuff of dreams for now

Adam Rutherford: 1) Buy extinct mammal hair from eBay; 2) Produce DNA sequence; 3) Artificially inseminate elephant; 4) Cook till term
Source: Science | guardian.co.uk | 20 Nov 2008 | 10:33 am

Happy Birthday: Space station celebrates 10 years (AP)

AP - NASA couldn't have staged it any better: 10 people in orbit for Thursday's 10th anniversary of the world's most elaborate and expensive housing project, the international space station.

Source: Yahoo! News: Science News | 20 Nov 2008 | 8:31 am

Charles Darwin's On the Origin of Species

New excerpts from Darwin's letters and diaries, along with contemporary cartoons and photographs, show how his revolutionary On the Origin of Species was received
Source: Science | guardian.co.uk | 20 Nov 2008 | 8:00 am

Herod may have been buried among lavish artwork (AP)

AP - King Herod may have been buried in a crypt with lavish Roman-style wall paintings of a kind previously unseen in the Middle East, Israeli archaeologists said Wednesday. The scientists found such paintings and signs of a regal two-story mausoleum, bolstering their conviction that the ancient Jewish monarch was buried there.

Source: Yahoo! News: Science News | 20 Nov 2008 | 5:23 am

Researchers ID Suite of Genes in Aging Process (HealthDay)

HealthDay - WEDNESDAY, Nov. 19 (HealthDay News) -- Genetic biomarkers that are highly accurate in determining physiological age have been identified by researchers at California's Buck Institute for Age Research, who said it may be possible to use these biomarkers to test anti-aging drugs.
Source: Yahoo! News: Science News | 20 Nov 2008 | 4:47 am

Bush 'seeks to ease wildlife law'

US environmentalists accuse President Bush of trying to rush through changes to the Endangered Species Act.
Source: BBC News | Science & Environment | UK Edition | 20 Nov 2008 | 4:05 am

Icy remains reveal mammoth's genetic makeup

Scientists have unravelled the genetic makeup of the woolly mammoth by analysing hairs plucked from carcasses recovered from the Siberian permafrost.

The feat was hailed as a milestone in genetic science yesterday and represents the first time an extinct animal has had its genome sequenced.

The first draft of the genetic code shows mammoths split into two groups about 2m years ago. One group became extinct about 45,000 years ago, while the other is thought to have lived on to as recently as 10,000 years ago.

"It has now become feasible to sequence a complete extinct animal, which is quite amazing," said Stephan Schuster, who led the research at Penn State University.

The achievement is an indication of the rapid progress in genetics. In 2003, the 13-year effort to read the human genome was completed at a cost of $2.6bn. The mammoth genome was read at one laboratory in less than a year and cost just over $1m.

Schuster's team gathered hair samples from 18 woolly mammoths and pieced together 3.3bn pairs of letters that make up about 70% of the animal's genetic code, the journal Nature reported.

By comparing the mammoth's DNA with that of the African elephant, the scientists identified sections of genetic code that may explain how the beasts adapted to harsh Arctic conditions. All elephants originated in Africa, but split into different species around 6.5m years ago. One group migrated to tropical Asia, while the mammoth headed for temperate Europe and eventually the Arctic.

Schuster said genetic diversity was very low in the two groups of mammoths. That may explain why the animals suddenly became extinct after enduring successive ice ages. The changing climate could have depleted their populations, leaving them vulnerable to disease and hunting when humans arrived in their regions about 23,000 years ago.

Analysis of the mammoth genome reveals it differs from the African elephant by only 0.6%. That is about half the difference between humans and chimpanzees, which split from a common ancestor at around the same time. The greater genetic gulf between humans and chimps suggests primates have evolved faster, probably because apes have historically been preyed on more than mammoths.

"It's an absolute first to have a genome sequence of an extinct animal, that's really a milestone," said Michael Hofreiter at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany.

Ultimately, scientists want to compare the genomes of mammoths that lived at different times to see how the species evolved. "Within the next decade, that is what people will go for. It's what evolutionary biologists dream of: seeing evolution in action," said Hofreiter.

The publication of the mammoth's genome is unlikely to lead to the resurrection of the beasts through cloning. While most of the genetic code is known, scientists do not have the technological knowhow to make chromosomes.

Next year, scientists are expected to reveal the full genetic code of our most recent ancestor, neanderthal man.

Genetics

Mammoth task: Scientists map DNA of ancient beast (AP)

AP - Bringing "Jurassic Park" one step closer to reality, scientists have deciphered much of the genetic code of the woolly mammoth, a feat they say could allow them to recreate the shaggy, prehistoric beast in as little as a decade or two.

Source: Yahoo! News: Science News | 20 Nov 2008 | 2:08 am

Palin, Alaska grapple with lower crude prices (Reuters)

Reuters - Falling oil prices will take a bite out of Alaska's state budget and put a damper on oil-field investment, Gov. Sarah Palin told a conference of major North Slope oil operators on Wednesday.
Source: Yahoo! News: Science News | 20 Nov 2008 | 1:57 am

Editorial: In praise of... stem cell research

Editorial: There is still a long way to go but the journey of success has begun
Source: Science | guardian.co.uk | 20 Nov 2008 | 12:19 am

Astronaut's bag joins 9,000 other bits of space debris

Space-walk to repair joint on solar panel wing takes seven hours after toolbag slips out of a greasy glove
Source: Science | guardian.co.uk | 20 Nov 2008 | 12:07 am

Sparrow numbers 'plummet by 68%'

The loss of green spaces in Britain has caused the number of house sparrows to drop sharply in the past 30 years.
Source: BBC News | Science & Environment | UK Edition | 20 Nov 2008 | 12:00 am

Astronauts install water recycler on space station

HOUSTON (Reuters) - Astronauts hooked up a water recycling system and installed two new bedrooms aboard the International Space Station on Wednesday while crew mates prepared for a second spacewalk to fix the outpost's power system.

Source: Reuters: Science News | 19 Nov 2008 | 11:27 pm

Genome Hacking Could Reverse-Engineer Extinct Woolly Mammoth

It might not make sense to pull woolly mammoths from the Ice Age into an age of global warming, but resurrecting that lost species just became a bit less far-fetched.

Using hair from 20,000-year-old specimens preserved in Siberian tundra, an international team of scientists finished a draft genome sequence of Mammuthus primigenius.

About one-fifth of the genome remains unidentified, but that should take just a few more years and scans. Once complete, it could be a template for would-be mammoth makers.

"It may one day become possible," said Pennsylvania State University biochemist and study co-author Stephan Schuster, "to mammoth-ify an African or Asian elephant genome."

Schuster's team was concerned solely with sequencing, not bringing back the mammoth. Nor were such potential resurrection efforts the most scientifically noteworthy implication of the research, published Wednesday in Nature. As the first sequence ever made with cells taken solely from hair, the genome is a tour-de-force of modern DNA sequencing technology. The researchers also found that certain genes conserved intact across the animal kingdom had mutated in mammoths, suggesting a radical and as-yet-unknown cold-weather adaptation.

But those results don't stir the imagination as do daydreams of woolly mammoths, extinct for six millennia but maintained in cultural memory, thundering across the 21st century. The obstacles to such biotechnological time travel are significant — but scientific advances are coming fast.

The first fragment of woolly mammoth genome was sequenced just two years ago, and researchers have since deciphered their mitochondrial DNA. And though some hypothetical methods of mammoth restoration — building a genome from scratch and putting it inside an elephant egg, or fertilizing an elephant egg with mammoth sperm — pose mammoth-sized technical problems, Schuster suggests a hack: working backwards from modern elephants.

"We've identified most of the differences between mammoths and African elephants. One could imagine reverse-engineering an elephant genome to become more like a mammoth," he said.

Schuster's plan won't be easy, but it may be possible. Less-complicated but fundamentally similar reverse-engineering is already used in mice and farm animals.

It's certainly easier than coding a mammoth genome from scratch: The first wholly synthetic genome, constructed last year by the J. Craig Venter institute, contained about 600,000 base pairs of DNA, compared to 4,000,000 in the mammoth genome. And using a 10,000-year-old cell for reproductive purposes is — in an already far-fetched discussion — especially unlikely.

"Japanese researchers have tried to do this for more than ten years by looking for intact nuclei from mammoth tissue, and they got nowhere," said Schuster. "It's absolutely obvious why: the genome stored in those chromosomes is completely shattered."

But even though modern elephants and woolly mammoths are quite similar, having diverged less than the 98 percent-genetically-identical humans and chimpanzees, reverse-engineering won't be easy.

"It's easy to make one or two changes, and they're suggesting at least 20,000," said George Seidel, a Colorado State University animal reproduction expert who was not involved in the study. "And will an elephant egg process that information in such a way as to function correctly?"

Nevertheless, even Seidel said that re-creation "is not out and out impossible," and raised the possibility of making elephant-mammoth hybrids to serve as an intermediate species on the path to a full, modern woolly mammoth.

A modern mammoth could easily be introduced in their ancestral Siberian homes, said Schuster. They would face less competition from humans than elephants in Africa, and be a star attraction of the newly-opened Pleistocene Park.

But just because something can be done doesn't mean it should, he said.

"From a scientific perspective, I think we would learn very little from doing this. A lot of what you want to learn about body plan and tissues we can get just by studying the carcasses," said Schuster.

"I would file it under the category of boutique science. The public is very curious. But you'd just generate a few specimens, a freak creature that you could put on display."

Sequencing the nuclear genome of the extinct woolly mammoth [Nature]

Images: 1. 3-D visualization / Steven W. Marcus 2. Woolly mammoth hair / Stephan Schuster 3. Mammoth skeleton / Stephan Schuster 4. Cave paintings from Grotte Chauvet / Carla216

WiSci 2.0: Brandon Keim's Twitter stream and Del.icio.us feed; Wired Science on Facebook.

Source: Wired: Wired Science | 19 Nov 2008 | 11:12 pm

Physicists Find Dark Matter, or Something Even More Strange

A new experiment may have found the first direct evidence of dark matter particles, a discovery that could begin to unravel one of the biggest mysteries in physics.

Theorists believe that dark matter, made up of of weakly-interacting massive particles, composes 23 percent of the universe, but no one has ever directly detected one of these WIMPs.

Now, physicists have announced they've spotted electrons with just about the amount of energy they would have expected to be made by a particular kind of WIMP entering the visible world.

John Wefel of Louisiana State University and colleagues report in Nature Wednesday that they could have detected "Kaluza-Klein" electron-positron pairs resulting from the annihilation of these WIMPS.

The KK particles are predicted by multiple-dimension theories of the universe and have long-been a leading candidate as the substance of dark matter. The new discovery then, if confirmed, would provide evidence that the fabric of space-time has many "compact" dimensions beyond the four that humans perceive.

"If the Kaluza–Klein annihilation explanation proves to be correct, this will necessitate a fuller investigation of such multidimensional spaces, with potentially important implications for our understanding of the Universe," the authors conclude.

Dozens of teams are working to understand the invisible dark matter and dark energy that when combined astrophysicists believe make up 95 percent of the universe. Most of the evidence for the dark stuff's existence comes through indirect observations: as physicist Myungkook James Jee put it last year, "We can't see a wind, but we can see it blow." So, the first direct detection of dark matter would be a landmark discovery.

Wefel's team sent a balloon carrying the "ATIC" particle detector aloft over Antarctica, where it measured the telltale charges and energies of electrons.

But the new detection isn't a sure indication of the existence of KK particles. Harvard astrophysicist Yousaf Butt argued that other astronomical objects could explain the creation of these high-energy electrons, in an editorial that accompanied the original paper. The leftovers from supernovas, spinning pulsars, or microquasars could all be responsible for the observations, or things could get even stranger.

"And let’s not forget that a completely new type of astrophysical object could also produce the detected electron excess; after all, pulsars were discovered only in 1967, and until 1992 we were blissfully unaware of microquasars," he wrote.

Further experiments seem likely to reveal the true source of this cosmic electron anomaly. With longer observation times or better detectors, scientists should be able to puzzle out whether the spectral signature of the detected electrons fits the dark matter thesis.

See Also:

Image: 1. Two trucks carrying helium gas cylinders are used to inflate this 30 million cubic foot balloon / Joachim B. Isbert / Nature. 2. "Content of the Universe"/ NASA. 3. The balloon awaits release from the launch vehicle / T. Gregory Guzik / Nature.

Citations:

"An excess of cosmic ray electrons at energies of 300–800 GeV"
J. Chang, J. H. Adams Jr, H. S. Ahn, G. L. Bashindzhagyan, M. Christl, O. Ganel, T. G. Guzik, J. Isbert, K. C. Kim, E. N. Kuznetsov, M. I. Panasyuk, A. D. Panov, W. K. H. Schmidt, E. S. Seo, N. V. Sokolskaya, J. W. Watts, J. P. Wefel, J. Wu & V. I. Zatsepin
doi:10.1038/nature07477
"A message from the dark side"
Yousaf M. Butt
News & Views: NATURE|Vol 456|20 November 2008

WiSci 2.0: Alexis Madrigal's Twitter , Google Reader feed, and webpage; Wired Science on Facebook.

Source: Wired: Wired Science | 19 Nov 2008 | 11:01 pm

Studies show stress can reshape the brain

Emotional, mental or physical tension can cause neurons to warp, according to research
Source: Science | guardian.co.uk | 19 Nov 2008 | 10:21 pm

Mammoth genome sequence may explain extinction

WASHINGTON (Reuters) - Researchers have sequenced the gene map of a long-extinct, mummified woolly mammoth, using DNA taken from its hair.

Source: Reuters: Science News | 19 Nov 2008 | 9:39 pm

Clump of dark matter may loom near solar system

WASHINGTON (Reuters) - A balloon-borne instrument soaring high over Antarctica has found evidence of a possible large clump of mysterious so-called dark matter relatively close to our solar system, scientists said on Wednesday.

Source: Reuters: Science News | 19 Nov 2008 | 9:36 pm

Israeli archaeologists unearth Herod family tombs

BEIT SAHOUR, West Bank (Reuters) - An Israeli archaeologist said on Wednesday he had unearthed what he believed were the 2,000-year-old remains of two tombs which had held a wife and daughter-in-law of the biblical King Herod.

Source: Reuters: Science News | 19 Nov 2008 | 8:54 pm

Why Can't Human Beings Breathe Underwater?

When you breathe in air, the air travels from your nose, down your trachea (windpipe), and into your lungs.
Source: Livescience.com | 19 Nov 2008 | 8:20 pm

Smoking's Many Myths Examined (LiveScience.com)

LiveScience.com - Unless you're living in a cave under the heart of Kentucky tobacco country, you know that smoking isn't exactly the best thing for your health. Scientists have succeeded in associating the habit with everything from countless cancers to bad-hair days, or so it seems with some reports.
Source: Yahoo! News: Science News | 19 Nov 2008 | 8:19 pm

View to a Krill: Secrets of Plankton Eyes

The world's simplest vision system can be found in tiny marine plankton.
Source: Discovery News Top Stories : Discovery Channel | 19 Nov 2008 | 8:10 pm

Hurricane season ending after record damage in US (AFP)

AFP - The Atlantic hurricane season in 2008 is coming to a close after producing 16 storms, including eight hurricanes, and inflicting record damage in the United States, a report by university researchers said on Wednesday.

Source: Yahoo! News: Science News | 19 Nov 2008 | 8:02 pm

DNA of Ice Age's Woolly Mammoth's Mapped

Scientists edge closer to reversing extinction by mapping the woolly mammoth's DNA.
Source: Discovery News Top Stories : Discovery Channel | 19 Nov 2008 | 7:04 pm

Marijuana Could Be Good for Memory — But Not if You Get High

Everybody knows a forgetful stoner, but research suggests that low doses of marijuana could be good for memory, and even help prevent Alzheimer's disease.

When given a compound similar to THC, the psychoactive ingredient in marijuana, rat brains displayed reduced levels of inflammation associated with Alzheimer's disease. The drug also stimulated the production of proteins associated with memory formation and brain cell growth.

"Everyone is aware that smoking too much marijuana impairs memory," said Ohio State University psychologist Yannick Marchalant. "Our work stays on the safe side — doses that we know are not going to impair memory, but improved it."

Marchalant and fellow OSU psychologist Gary Wenk previously showed that marijuana can improve memory formation in rats. The latest research, presented at this week's Society for Neuroscience annual meeting, provides a detailed look at THC's effect on the brain.

It's far too soon to extrapolate the findings directly to people, but the researchers hope it will inform the development of targeted (and legal) drugs — and in the meantime, they say, there might be a role for marijuana in preventing age-related neurodegeneration.

"What we're looking at is preventing the inflammation-induced impairment of memory that you see in normal and pathological aging," said Marchalant. "We'll try to find safe drugs that you can use 10 or 20 years beforehand."

The compound used by the researchers isn't identical to THC, but marijuana likely produces some of the same effects, he said.

Marchalant cautioned that any benefits wouldn't be experienced by people whose brains have already started to deteriorate, nor those whose brains are still forming. But for adults looking to prevent dementia, marijuana could play a role — albeit at very small doses, well below the level of psychoactivity.

"It will take the recreational use out of it," said Marchalant, who made a rough extrapolation from rat doses to a single human puff of pot.

"It's hard to say, no you shouldn't," to someone who wants to self-medicate, said Marchalant, but he stressed that the research is still highly experimental.

"We still have a lot of work ahead to do in animals," he said.

Image: TheTruthAbout...

WiSci 2.0: Brandon Keim's Twitter stream and Del.icio.us feed; Wired Science on Facebook.

Source: Wired: Wired Science | 19 Nov 2008 | 6:39 pm

Mammoth's genome pieced together

A US-Russian team announces that it has sequenced most of the genome of a woolly mammoth found in Siberia.
Source: BBC News | Science & Environment | UK Edition | 19 Nov 2008 | 6:34 pm

Extinct Woolly Mammoth's DNA Mapped

Scientists have unraveled much of the genetic code of an extinct animal.
Source: Livescience.com | 19 Nov 2008 | 6:28 pm

Scientists reconstruct woolly mammoth genome

Scientists have decoded the genome of the woolly mammoth by analysing hairs plucked from carcasses recovered from the Siberian permafrost.

The feat was hailed as a milestone in genetic science yesterday and is the first time an extinct animal has had its genome sequenced.

The first draft of the genetic code reveals that mammoths split into two groups around 2m years ago. One of the groups became extinct around 45,000 years ago, while the other is thought to have lived on, to as recently as 10,000 years ago.

The achievement is a startling sign of the rapid progress genetics has made in recent decades. In 2003, scientists announced that the 13-year effort to read the human genome had finally been completed, at a cost of around $2.6 billion. The mammoth genome was read at one laboratory in less than a year at a cost of just over $1m.

"It has now become feasible to sequence a complete extinct animal, which is quite amazing," said Stephan Schuster, who led the research at Penn State University in the US.

Schuster's team gathered hair samples from 18 woolly mammoths and pieced together 3.3bn pairs of letters that make up around 70% of the animal's genetic code, according to a report in the journal Nature.

By comparing the mammoths' DNA with that of the African elephant, the scientists identified sections of genetic code that may explain how the beasts adapted to harsh Arctic conditions. African and Asian elephants evolved larger ears than the mammoth to help them cool down, but mammoths are also thought to have evolved differences in their metabolism and the way they stored fat.

All elephants originated in Africa, but split into different species around 6.5 million years ago. One group migrated to tropical Asia, while the ancestors of the mammoth headed for temperate Europe and eventually the Arctic.

Schuster said genetic diversity was very low in the two groups of mammoth, indicating that they were all very closely related. That may explain why the animals suddenly went extinct after enduring traumatic climatic swings through successive ice ages. The changing climate could have depleted populations, leaving them vulnerable to diseases or hunting when humans arrived in the region around 23,000 years ago.

Analysis of the mammoth genome reveals it differs from the African elephant by only 0.6%. That is about half the difference between humans and chimpanzees, which split from a common ancestor at around the same time. The greater genetic gulf between humans and chimps suggests primates have evolved faster, probably because historically apes have been preyed on more than mammoths.

The mammoths managed to adapt to the chilly environment in which they found themselves by growing long hair, even after their ancestors had lost theirs.

Ultimately, scientists want to compare the genomes of mammoths that lived at different times to see how the species evolved over thousands of years. "Within the next decade, that is what people will go for. It's what evolutionary biologists dream of – seeing evolution in action," said Hofreiter.

The publication of the mammoth's genome is unlikely to lead to the resurrection of the beasts through cloning. While most of their genetic code is known, scientists do not have the technological know-how to make their chromosomes in the laboratory.

Theoretically, it would be possible to recreate a mammoth by genetically modifying an elephant embryo to carry all of the 400,000 important genetic differences that exist between the species. With today's technology, however, scientists can only make one genetic change at a time.

Next year, scientists are expected to reveal the full genetic code of our own most recent ancestor, the Neanderthal. Genetic differences between Neanderthals and modern humans could reveal why humans came to be the dominant species on Earth.

Rare Microphotographs Resurface After 150 Years

Drawing was a terribly important part of science until the mid-19th century. Without photography, scientists, particularly in the life sciences, had to document what they saw with painstaking illustrations.

The clarity and "realness" of photographs eventually relegated scientific drawing to a hobby, but it didn't happen overnight. Photographers working at the microscopic scale had to devise new emulsion chemistries and types of equipment to capture clear images of tiny things.

Leading the charge was Auguste-Adolphe Bertsch, who worked to overcome any challenge that scientists threw at him. Unfortunately, he died during leftist social unrest in France in 1871. As a result, his pioneering work languished in the archives of the French photography society, Société française de photographie, until Corey Keller dug them up for her new exhibit about early scientific photography, Brought to Light Photography and the Invisible, at San Francisco's Museum of Modern Art.

"Photographers would deposit their pictures with this organization sort of as a way of staking their claim to achievements," Keller told Wired.com. "So these pictures went there directly from the man who made them and have been there ever since."

In this five-part series, we're walking through the Brought to Light exhibit with Keller, who spent five years scouring dusty archives, primarily in Europe, to dig up dozens of haunting photographs from the period. Many of the images have never been seen, except by their creators. This installment brings you the story of pioneering microphotographers like Bertsch and their struggle to bring technological advancement to traditional scientific practices.

Even as they solved technical challenges, the photographers faced social resistance. The idea of representing a specific living thing instead of a generalized abstraction of an organism forced scientists to let go of long-held notions about their discipline.

"Prior to the 19th century, the scientific illustrations tend to represent a type, an ideal. So if you were going to do a picture of a flower, for example, the illustrator would look at 20 flowers and then take the common features and make an ideal flower," said Keller. "So, if that particular one happens to have a defective petal or something peculiar to it, you never really know: Does that photograph substitute then for that type of flower in general, or does it only represent that one specimen?"

While it may have posed a challenge for scientists of the 19th century, it's the unique nature of each photograph taken during this early period that wows us, even now.

Credits: Photos from the Brought to Light show in the video include: Auguste-Adolphe Bertsch, Male itch mite, ca. 1853–57; San Francisco Museum of Art; William Henry Fox Talbot, Photomicrograph of moth wings, ca. 1840; Calotype negative, Arthur E. Durham, Photomicrograph of a fly, ca.1865; Arthur E. Durham, Photomicrograph of a flea, 1863 or 1864. Other images, like the scientific drawings and microscopic photography setup from Manufacturer and Builder courtesy of the Library of Congress' American Memory collection.

See Also:

WiSci 2.0: Alexis Madrigal's Twitter , Google Reader feed, and webpage; Wired Science on Facebook.

Source: Wired: Wired Science | 19 Nov 2008 | 5:43 pm

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