Ancient Maya Swapped Culture With Multiple Groups
Until now, two theories have dominated the debate concerning the origin of the Maya civilization: one suggesting that the Maya developed almost entirely on their own in what is now southern Mexico, Guatemala, and Belize, and another suggesting that the older Olmec civilization was the Maya’s dominant cultural influence. Takeshi Inomata and Daniela Triadan, a husband-and-wife team from the University of Arizona in Tucson, along with colleagues from the U.S. and Japan, however, found that neither of these theories could tell the full story of the Maya. According to the researchers, the plazas and pyramids at Ceibal, an ancient Maya site in Guatemala, probably arose from broad cultural exchanges that took place across southern Mesoamerica from about 1,000 to 700 BCE.
This research appeared in the 26 April issue of Science.
[Reconstruction: Daniela Triadan; Photo: Takeshi Inomata. Click for caption information.]
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© 2013 American Association for the Advancement of Science. All Rights Reserved.
Whales Get Feeding Tips From Their Friends
Humpback whales pick up feeding techniques from other whales, a new study reports. The findings offer evidence that behaviors are spread through cultural transmission in animals other than humans and non-human primates.
Read more about this research from the 26 April issue of Science here.
[Image courtesy of Jennifer Allen/Whale Center of New England. Click the image for more information.]
© 2013 American Association for the Advancement of Science. All Rights Reserved.
Eating Like Locals: Social Learning & Culture in Monkeys
Most travelers want to eat what the locals are eating. New research now shows that wild vervet monkeys will also “eat what the locals are eating,” and switch food preferences when joining a new group or culture. The findings offer evidence that social learning – learning from others rather than through individual trial and error – is a more powerful force for shaping wild animal behavior than previously thought.
Read more about this research from the 26 April issue of Science here.
[Image courtesy of Erica van de Waal. Click the image for more information.]
© 2013 American Association for the Advancement of Science. All Rights Reserved.
Light Switches Brain Signaling
A new study explains why long days, with plenty of light, are stressful for rats, causing the neurons in the brains of these nocturnal creatures to produce less of the neurotransmitter dopamine. Typically, specific neurotransmitters are released by specific neurons, though the ability of neurons to switch the transmitters they release in certain conditions has been known. Now, a new study shows that this “neurotransmitter switching” underlies the stress response of adult rats to prolonged light.
Read more about this research from the 26 April issue of Science here.
[Image courtesy of Davide Dulcis and Pouya Jamshidi. Click the image for more information.]
© 2013 American Association for the Advancement of Science. All Rights Reserved.
Grand Challenges in Science Education
The 21st-century scientific workforce needs new skills and knowledge to keep pace with ever-changing technology. Larger, more diverse student populations clamor for access to knowledge. All global citizens, whether in a doctor’s office or polling booth, must be better informed. All of these needs call for expanded, improved science education. In this special issue, we have invited experts to discuss the most important challenges facing science education. See the special section beginning on page 290. Images: Thinkstock
Anyone wishing to use the cover of Science must contact AAAS to request permission to do so.
© 2013 American Association for the Advancement of Science. All Rights Reserved.
Exclusive Breastfeeding Curbs HIV in Breast Milk
HIV-infected women who want to breastfeed should do so exclusively (no feeding with other fluids or foods) for the first six months of a baby’s life, a new study of HIV-infected mothers in Zambia suggests. Women who chose long-term exclusive breastfeeding may have the lowest risk of transmitting the virus to their babies through breast milk, the findings show. In this podcast, author Louise Kuhn discusses how breastfeeding affects levels of HIV in the breast milk of infected mothers.
[Audio file © Science/AAAS]
Read more about this research from the 17 April issue of Science Translational Medicine here.
© 2013 American Association for the Advancement of Science. All Rights Reserved.
Where Has All the Charcoal Gone?
A new study helps to explain why scientists have not found expected levels of biochar (a type of charcoal) in the world’s soils. Biochar — which is generated from the burning of biomass such as wood and plants, and then deposited in soil — is important because its absorptive properties help it remove carbon from the atmosphere (which can in turn help to mitigate climate change). The burning of biomass generates tens to hundreds of millions of tons of biochar annually, about half of which was thought to be preserved for millennia in soils and river sediment. Using a novel process, Rudolf Jaffé and colleagues help explain why the expected levels of biochar haven’t been found in soils and rivers.
Read more about this research from the 19 April issue of Science here.
[Image courtesy of Dr. Stefan Doerr. Click the image for more information.]
© 2013 American Association for the Advancement of Science. All Rights Reserved.
First Antarctic Freeze Brought New Plankton
About 34 million years ago, as ice was covering the surface of Antarctica, plankton in the Southern Ocean was undergoing an abrupt and dramatic reorganization, researchers say. Alexander Houben and colleagues used records of fossilized cysts, which were left behind by microorganisms called dinoflagellates, to study the ecosystems that surrounded Antarctica during its transition to a continent-wide glacier.
Read more about this research from the 19 April issue of Science here.
[Image courtesy of Annick Fehr, Kevin Welsh and Trevor Williams. Click the image for more information.]
© 2013 American Association for the Advancement of Science. All Rights Reserved.
Mental Maps in Bats and Rats
