Study shows humans are evolving faster than previously thought

Photograph: Imagno/Getty Images

By Hannah Devlin

Humans are evolving more rapidly than previously thought, according to the largest ever genetics study of a single population.

Scientists reached the conclusion after showing that almost every man alive can trace his origins to one common male ancestor who lived about 250,000 years ago. The discovery that so-called “genetic Adam”, lived about 100,000 years more recently than previously understood suggests that humans must have been genetically diverging at a more rapid rate than thought.

Kári Stefánsson, of the company deCODE Genetics and senior author of the study, said: “It means we have evolved faster than we thought.”

The study also shows that the most recent common male ancestor was alive at around the same time as “mitochondrial Eve” – the last woman to whom all females alive today can trace their mitochondrial DNA.

Unlike their biblical counterparts, genetic Adam and Eve were by no means the only humans alive, and although they almost certainly never met, the latest estimate which gives a closer match between their dates makes more sense, according to the researchers.

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New lobster-like predator found in 508 million-year-old fossil-rich site

Credit: Jean-Bernard Caron/Royal Ontario Museum

By Phys.org

What do butterflies, spiders and lobsters have in common? They are all surviving relatives of a newly identified species called Yawunik kootenayi, a marine creature with two pairs of eyes and prominent grasping appendages that lived as much as 508 million years ago – more than 250 million years before the first dinosaur.

The fossil was identified by an international team led by palaeontologists at the University of Toronto (U of T) and the Royal Ontario Museum (ROM) in Toronto, as well as Pomona College in California. It is the first new species to be described from the Marble Canyon site, part of the renowned Canadian Burgess Shale fossil deposit.

Yawunik had evolved long frontal appendages that resemble the antennae of modern beetles or shrimps, though these appendages were composed of three long claws, two of which bore opposing rows of teeth that helped the animal catch its prey.

“This creature is expanding our perspective on the anatomy and predatory habits of the first arthropods, the group to which spiders and lobsters belong,” said Cedric Aria, a PhD candidate in U of T’s Department of Ecology & Evolutionary Biology and lead author of the resulting study published this week in Palaeontology. “It has the signature features of an arthropod with its external skeleton, segmented body and jointed appendages, but lacks certain advanced traits present in groups that survived until the present day. We say that it belongs to the ‘stem’ of arthropods.”

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NASA’s Curiosity rover finds fresh signs of ingredients for life on Mars

Photo: NASA/JPL-Caltech/MSSS

By Amina Khan

Mars’s life-friendly past just got friendlier. Using samples previously collected by the NASA rover Curiosity, scientists have discovered evidence of nitrates in Martian rock: nitrogen compounds that on Earth are a crucial source of nutrients for living things.

The findings, published in the journal Proceedings of the National Academy of Sciences, lend further support to the idea that the Red Planet, now barren and dry, could once have hosted habitable environments.

Although planetary scientists have been on the hunt for organic carbon – the type of carbon-containing molecules that could be used and produced by living things – nitrogen also plays an essential role in life as we know it, said lead author Jennifer Stern, a planetary geochemist at NASA Goddard Space Flight Center in Greenbelt, Md.

For example, nitrogen is a key component of nucleobases that make up RNA and DNA, and of amino acids, the building blocks of proteins.

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No Child Left Behind Law Faces Its Own Reckoning

Michael F. McElroy for The New York Times

By Motoko Rich and Tamar Lewin

Ginn Academy, the first and only public high school in Ohio just for boys, was conceived to help at-risk students make it through school — experimenting with small classes, a tough discipline code and life coaches around the clock.

Its graduation rate was close to 88 percent last year, compared with 64 percent for the Cleveland Metropolitan School District as a whole. And it has enjoyed some other victories. There is the junior whose test scores are weak but who regularly volunteers at a food bank. And the senior proudly set to graduate this spring who used to attend school so irregularly that he had to be collected at home each morning by a staff member.

But under No Child Left Behind, the signature education initiative of the George W. Bush administration, the academy, which opened in 2007, was consistently labeled low performing because it did not make the required “adequate yearly progress” in raising test scores.

Nicholas A. Petty, the principal, said, “I wouldn’t say stop making us be judged by the tests at all, but get a better system that really monitors students on more of an individual basis.”

As Congress debates a rewrite of the No Child Left Behind law, Mr. Petty may well see that happen.

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NASA discovers an underground ocean on Jupiter’s largest moon

Image credit: NASA, ESA and A. Feild

By Rachel Feltman

NASA announced evidence on Thursday that Jupiter’s largest moon, Ganymede, has a saltwater ocean under its icy surface. The ocean seems to have more water than all the water on Earth’s surface, according to new Hubble observations.

Scientists estimate that the ocean is 60 miles thick, which is about 10 times deeper than Earth’s oceans. But unlike our salty waters, Ganymede’s ocean is buried under 95 miles of ice.

While scientists have speculated since the 1970s about the presence of an ocean on Ganymede — the largest moon in our solar system — until now the only observational evidence came from a brief flyby by the Galileo spacecraft, which didn’t observe the moon long enough to confirm a liquid ocean.

“This discovery marks a significant milestone, highlighting what only Hubble can accomplish,” John Grunsfeld, assistant administrator of NASA’s Science Mission Directorate at NASA Headquarters, said in a statement. “In its 25 years in orbit, Hubble has made many scientific discoveries in our own solar system. A deep ocean under the icy crust of Ganymede opens up further exciting possibilities for life beyond Earth.”

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No religious text should be Tennessee’s official book

Photo: Getty Images/iStockphoto

By David Plazas

Tennessee lawmakers have filed unconstitutional, divisive and misguided bills that would make the Holy Bible the official state book.

Both Tennessee and United States’ constitutions expressly respect the rights of individuals to worship freely, but also prohibit the state from favoring one religion over another.

This protects all of us, whether we choose to belong to a religious congregation or not.

We can live peacefully in society without religious tests and choose which religious institutions to attend and which scriptures to honor.

Making a religious text the state’s official tome isn’t like the innocuous act of choosing a state beverage (milk), fruit (tomato) or rock (limestone). This sends a message of exclusion and divisiveness in a state that is becoming more and more diverse.

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Flower-friendly farms ‘boost bee populations’

By Helen Briggs

Planting farmland with strips of flowers can boost the number of wild bumblebees, a study has confirmed.

Not only does it attract foraging bees, but it also encourages nesting, say researchers at University of Sussex.

In past decades, many bumblebee species have declined, due to a number of factors, including intensive farming.

The study, published in Molecular Ecology, suggest farms given funding to improve the environment can increase the size of wild bumblebee populations.

However, rarer species, which forage over shorter distances, may need special attention, as the method of management appeared to have no effect, said scientists.

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