Last Monday of the year and the time for science talk is here. Time to brighten your day with selections from science sites across the globe. New discoveries, new takes on old knowledge, and other bits of news are all available for the perusing in today's information world. Today's tidbits include evidence suggests starvation did not cause the extinction of the sabre tooth cats, Amazon deforestation brings loss of microbial communities, how excess holiday eating disturbs your food clock, bumblebees do best where there is less pavement and more floral diversity, and discovery of an ancient Antarctic fossil forest.
Pull up that comfy chair and grab a spot on the porch. There is always plenty of room for everyone. Another session of Dr. Possum's science education, entertainment, and potluck discussion is set to begin.
Sabre tooth cats roamed North America in the late Pleistocene just before their extinction.
The researchers report that previous examinations of the jaws of the American lions and saber-tooth cats from this period found that they have more than three times as many broken canines and interpret this as additional evidence that supports their conclusion that most of the excess tooth breakage occurred during capture instead of feeding.The exact cause of the cats' demise remains to be determined.
In addition, the researchers argue that the large size of the extinct carnivores and their prey can help explain the large number of broken teeth. The saber-toothed cats were about the size of today's African lion and the American lion was about 25 percent larger. The animals that they preyed upon likely included mammoths, four-ton giant ground sloths and 3,500-pound bison.
Larger teeth break more easily than smaller teeth. So larger carnivores are likely to break more canine teeth when attempting to take down larger prey, the researchers argue. They cite a study that modeled the strength of canine teeth that found the canines of a predator the size of fox can support more than seven times its weight before breaking while a predator the size of lion can only support about four times its weight and the curved teeth of the saber-toothed cats can only support about twice its weight.
A troubling loss of microbial diversity is reported by researchers studying the effects of deforestation of the Amazon.
Findings in part validated previous research showing that bacteria in the soil became more diverse after conversion to pasture. However, in its fourth year, their study overcame limitations of earlier investigations to show that changes in microbial diversity occurred over larger geographic scales.The metabolic even keel maintained by a number of different processes is known as our 'food clock.'
Findings do not support earlier study conclusions, instead they show that the loss of restricted ranges for different bacteria communities results in a biotic homogenization and net loss of diversity overall. Scientists worry that the loss of genetic variation in bacteria across a converted forest could reduce ecosystem resilience. The researchers hope their work will provide valuable data to those making decisions about the future of the Amazon rainforest.
The food clock is there to help our bodies make the most of our nutritional intake. It controls genes that help in everything from the absorption of nutrients in our digestive tract to their dispersal through the bloodstream, and it is designed to anticipate our eating patterns. Even before we eat a meal, our bodies begin to turn on some of these genes and turn off others, preparing for the burst of sustenance – which is why we feel the pangs of hunger just as the lunch hour arrives.All that excess food causes the system clock to struggle to adjust.
Scientist have known that the food clock can be reset over time if an organism changes its eating patterns, eating to excess or at odd times, since the timing of the food clock is pegged to feeding during the prime foraging and hunting hours in the day. But until now, very little was known about how the food clock works on a genetic level.
Again from the department of we might have guessed that fact comes news of bumblebees doing better in areas with less pavement and more floral diversity.
In addition to finding that pavement negatively affects the bees, the scientists discovered that:The discovery of a 100-million-year-old fossil forest on the coast of New Zealand offers insight into life near the South Pole.
Bees will move longer distances to find patches of flowers that are rich in species; it’s not floral density that determines how far a bumblebee will fly, but floral diversity.
Bees will also forage further away from their home nest if the surrounding landscape is less heterogeneous.
Large trees in their original living position, early flowering plants, seed cones and rare insects preserved in a rock formation were discovered by researchers in the Chatham Islands. The find reveals what is believed to be the first records of life close to the South Pole during the Cretaceous period, a time of extreme greenhouse conditions 145-65 million years ago.
Knucklehead's Photo of the Week
Copper Band Butterfly
©Knucklehead, all rights reserved, presented by permission. (Click on the image to see more in the same series.)
Other Worthy Stories of the Week
Wired Science top image galleries of the year
The most amazing science images of the year
Ups and downs of biodiversity after mass extinction
Fluctuating environment may have driven human evolution
Science's breakthrough of the year: Discovery of the Higgs Boson
Chinese medicine yields secrets to scientists
Cave dwelling nettle discovered in China
Two new species of orchid found in Cuba
A new type of nerve cell found in the brain
Scientists help explain scarcity of anti-matter
Scientists unearth King David era temple near Jerusalem
Researchers use earthworms to create quantum dots
Images from the Swift satellite
For even more science news:
General Science Collectors:
BBC News Science and Environment
Eureka Science News
A Few Things Ill Considered Techie and Science News
Cantauri Dreams space exploration
Coctail Party Physics Physics with a twist.
Deep Sea News marine biology
List of Geoscience Blogs
Tetrapod Zoologyvertebrate paleontology
Science RSS Feed: Medworm
The Skeptics Guide to the Universe--a combination of hard science and debunking crap
At Daily Kos:
This Week in Science by DarkSyde
Overnight News Digest:Science Saturday by Neon Vincent. OND tech Thursday by rfall.
Pique the Geek by Translator Sunday evenings about 9 Eastern time
All diaries with the DK GreenRoots Tag.
All diaries with the eKos Tag
A More Ancient World by matching mole
SciTech at Dkos.
Sunday Science Videos by palantir