The Penguin Bar

Evolution has been caught in the act, according to scientists who are decoding how a species of Australian lizard is abandoning egg-laying in favor of live birth.Along the warm coastal lowlands of New South Wales map, the yellow-bellied three-toed skink lays eggs to reproduce. But individuals of the same species living in the state’s higher, colder mountains are almost all giving birth to live young.Only two other modern reptiles—another skink species and a European lizard—use both types of reproduction. Related: “Virgin Birth Expected at Christmas—By Komodo Dragon.”Evolutionary records shows that nearly a hundred reptile lineages have independently made the transition from egg-laying to live birth in the past, and today about 20 percent of all living snakes and lizards give birth to live young only.

via Evolution in Action: Lizard Moving From Eggs to Live Birth.

Scientists have identified a previously unknown type of ancient human through analysis of DNA from a finger bone unearthed in a Siberian cave.

The extinct “hominin” (human like creature) lived in Central Asia between 48,000 and 30,000 years ago.

An international team has sequenced genetic material from the fossil showing that it is distinct from that of Neanderthals and modern humans.

Details of the find, dubbed “X-woman”, have been published in Nature journal.

via BBC News – DNA identifies new ancient human dubbed ‘X-woman’.

Oxygen isotopes in clamshells may provide the most detailed record yet of global climate change, according to a team of scientists who studied a haul of ancient Icelandic molluscs.

Most measures of palaeoclimate provide data on only average annual temperatures, says William Patterson, an isotope chemist at the University of Saskatchewan in Saskatoon, Canada, and lead author of the study1. But molluscs grow continually, and the levels of different oxygen isotopes in their shells vary with the temperature of the water in which they live. The colder the water, the higher the proportion of the heavy oxygen isotope, oxygen-18.

via Shellfish could supplant tree-ring climate data : Nature News.

Climate scientists have delivered a powerful riposte to their sceptical critics with a study that strengthens the case for saying global warming is largely the result of man-made emissions of greenhouse gases.

The researchers found that no other possible natural phenomenon, such as volcanic eruptions or variations in the activity of the Sun, could explain the significant warming of the planet over the past half century as recorded on every continent including Antarctica.

It is only when the warming effect of emitting millions of tonnes of carbon dioxide into the atmosphere from human activity is considered that it is possible to explain why global average temperatures have risen so significantly since the middle of the 20th century.

via Humans must be to blame for climate change, say scientists – Climate Change, Environment – The Independent.

Nearly a third of Texans believe humans and dinosaurs roamed the earth at the same time, and more than half disagree with the theory that humans developed from earlier species of animals, according to the University of Texas/Texas Tribune Poll.

via Meet the Flintstones | The Texas Tribune.

Americans should be ashamed of these figures.

Well, to put it bluntly, there is no such thing as a mass-energy relation. What does exist is a mass-energy-momentum relation. The equation Einstein came up with more than a century ago can be considered a degenerate form of the mass-energy-momentum relation for vanishing momentum. Einstein was very well aware of this, and in later papers repetitively stressed that his mass-energy equation is strictly limited to observers co-moving with the object under study. However, very, very few people seem to have paid attention to Einstein's warnings, nor to any of the more recent warnings. Even worse, the vast majority of authors of popular science books take great liberty in applying E=mc2 to objects moving at speeds close to the speed of light, and then declare mass to increase with velocity in an attempt to recover consistency in what has become an incoherent mix of relativistic and Newtonian dynamics. Theoretical physicist Lev Okun refers to this practice as a “pedagogical virus”.

What I consider truly amazing, is how few people are aware of the mass-energy-momentum relation. In contrast to the widely popularized equation E=mc2, the mass-energy-momentum relation is a direct result of the fundamental principles of relativity theory, and provides true insight into the basics of relativity.

via What’s Wrong With E=MC^2?.

A beam of white light is made up of all the colours in the spectrum. The range extends from red through to violet, with orange, yellow, green and blue in between. But there is one colour that is notable by its absence.

Pink (or magenta, to use its official name) simply isn’t there. But if pink isn’t in the light spectrum, how come we can see it?

via Magenta Ain’t A Colour.

February 12th is the 200th anniversary of the birth of Charles Darwin. This year is also the 150th anniversary of the publication of Origin of the Species – arguably one of the most important scientific publications ever. In honor of Darwin’s idea and the subsequent scientific triumph of evolutionary theory, I am posting my refutation of a popular creationist internet meme. Creationists love to imagine that they have dismantled evolution or discovered it’s “major flaws,” however they only succeed in exposing the major flaws in their understanding of evolution and ability to reason.

Read the whole article. Via Skepticblog » Ten Major Flaws of Evolution – A Refutation.

Scientists have sequenced the DNA from four frozen hairs of a Greenlander who died 4,000 years ago in a study they say takes genetic technology into several new realms.

Surprisingly, the long-dead man appears to have originated in Siberia and is unrelated to modern Greenlanders, Morten Rasmussen of the University of Copenhagen and colleagues found.

“This provides evidence for a migration from Siberia into the New World some 5,500 years ago, independent of that giving rise to the modern Native Americans and Inuit,” the researchers wrote in Thursday's issue of the journal Nature.

Not only can the findings help transform the study of archeology, but they can help answer questions about the origins of modern populations and disease, they said.

via Ancient Greenland gene map has a surprise – Yahoo! News.

NASA today released the most detailed set of images ever taken of the distant dwarf planet Pluto. The images taken by NASA's Hubble Space Telescope show an icy and dark molasses-colored, mottled world that is undergoing seasonal changes in its surface color and brightness. Pluto has become significantly redder, while its illuminated northern hemisphere is getting brighter. These changes are most likely consequences of surface ices sublimating on the sunlit pole and then refreezing on the other pole as the dwarf planet heads into the next phase of its 248-year-long seasonal cycle. The dramatic change in color apparently took place in a two-year period, from 2000 to 2002.

The Hubble images will remain our sharpest view of Pluto until NASA's New Horizons probe is within six months of its Pluto flyby. The Hubble pictures are proving invaluable for picking out the planet's most interesting-looking hemisphere for the New Horizons spacecraft to swoop over when it flies by Pluto in 2015.

Though Pluto is arguably one of the public's favorite planetary objects, it is also the hardest of which to get a detailed portrait because the world is small and very far away. Hubble resolves surface variations a few hundred miles across, which are too coarse for understanding surface geology. But in terms of surface color and brightness Hubble reveals a complex-looking and variegated world with white, dark-orange, and charcoal-black terrain. The overall color is believed to be a result of ultraviolet radiation from the distant Sun breaking up methane that is present on Pluto's surface, leaving behind a dark and red carbon-rich residue.

When Hubble pictures taken in 1994 are compared with a new set of images taken in 2002 to 2003, astronomers see evidence that the northern polar region has gotten brighter, while the southern hemisphere has gotten darker. These changes hint at very complex processes affecting the visible surface, and the new data will be used in continued research.

via HubbleSite – NewsCenter – New Hubble Maps of Pluto Show Surface Changes (02/04/2010) – The Full Story.