(Here it is: Tuesday. Which is sort of like Monday. And therefore time, once again, for Science News & Wisdom from the esteemed Dr. Possum. Said News & Wisdom appearing here every Monday. Or on some day like a Monday.)
The time has arrived one more time. Time for more science talk. New discoveries, new takes on old knowledge, and other bits of news are all available for the perusing in today’s information world. Over the fold are selections from the past week from a few of the many excellent science news sites around the world. Today’s tidbits include carbon dioxide is driving fish ‘crazy’, harp seals on thin ice, most distant dwarf galaxy detected, genetic analysis shows tortoise species thought to be long extinct to be alive today, and the first physical evidence of tobacco in a Mayan container. Pull up that comfy chair and grab a spot near the fireside. There is always plenty of room for everyone. Another session of Dr. Possum’s science education, entertainment, and potluck discussion is set to begin.
Rising carbon dioxide concentrations from human activity may be damaging the central nervous systems of fish and endangering their ability to survive the future.
Prof. Munday and his colleagues began by studying how baby clown and damsel fishes performed alongside their predators in CO2-enriched water. They found that, while the predators were somewhat affected, the baby fish suffered much higher rates of attrition.
“Our early work showed that the sense of smell of baby fish was harmed by higher CO2 in the water—meaning they found it harder to locate a reef to settle on or detect the warning smell of a predator fish. But we suspected there was much more to it than the loss of ability to smell.”
The team then examined whether fishes’ sense of hearing—used to locate and home in on reefs at night, and avoid them during the day—was affected. “The answer is, yes it was. They were confused and no longer avoided reef sounds during the day. Being attracted to reefs during daylight would make them easy meat for predators.”
Other work showed the fish also tended to lose their natural instinct to turn left or right—an important factor in schooling behaviour which also makes them more vulnerable, as lone fish are easily eaten by predators.
With 32 years of gradual warming Arctic ice is thinning and leaving harp seals in trouble.
[S]easonal sea ice cover in all four harp seal breeding regions in the North Atlantic has declined by up to 6 percent a decade since 1979, when satellite records of ice conditions in the region began.
Harp seals rely on stable winter sea ice as safe places to give birth and nurse their young until the pups can swim and hunt on their own. Female seals typically seek out the thickest, oldest ice packs in sub-Arctic waters each February and March, and have adapted to the spring melt by developing unusually short, 12-day nursing periods.
Recent reports that some harp seals are whelping in new breeding grounds off East Greenland indicate some shifting may be taking place, but thousands still return each year to traditional breeding grounds in the Gulf of St. Lawrence or along the Front, off Newfoundland, regardless of ice conditions.
A new dwarf galaxy almost 10 billion light years from Earth has been detected.
Galaxies like our own are believed to form over billions of years through the merging of many smaller galaxies. So it’s expected that there should be many smaller dwarf galaxies buzzing around the Milky Way. However, very few of these tiny relic galaxies have been observed which has led astronomers to conclude that many of them must have very few stars or possibly may be made almost exclusively of dark matter.
Scientists theorize the existence of dark matter to explain observations that suggest there is far more mass in the universe than can be seen. However, because the particles that make up dark matter do not absorb or emit light, they have so far proven impossible to detect and identify. Computer modeling suggests that the Milky Way should have about 10,000 satellite dwarf galaxies, but only 30 have been observed. dwarf galaxy almost 10 billion light years away from earth has been detected.
With advances in genetic analysis and new reports comes the news of giant tortoises long thought to be extinct alive in a remote location in the Galapagos Islands.
A team of Yale researchers visiting Volcano Wolf on the northern tip of Isabela Island in 2008 took blood samples from more than 1600 tortoises and compared them to a genetic database of living and extinct tortoise species. An analysis detected the genetic signatures of C. elephantopus in 84 Volcano Wolf tortoises, meaning one of their parents was a purebred member of the missing species. In 30 cases breeding had taken place within the last 15 years. Since the lifespan of tortoises can exceed 100 years, there is a high probability that many purebreds are still alive.
The use of tobacco has roots in ancient times in North America as shown by the presence of the substance in a Mayan container.
In recent years, archaeologists have begun to use chemical analysis of residues from ancient pottery, tools, and even mummies in an attempt to piece together minute clues about ancient civilizations. Among the potential problems with isolating a residue for analysis is preservation and contamination. Many vessels serve multiple purposes during their lives, resulting in muddled chemical data. Once the vessels are discarded, natural processes such as bacteria and water can destroy the surface of materials, erasing important evidence. Additionally, researchers must be attentive to archaeological field handling and laboratory treatment of the artifacts that might lead to cross contamination by modern sources.
To make their discovery, the researchers had a unique research opportunity: a more than 1,300-year-old vessel decorated with hieroglyphics that seemingly indicated the intended contents. Additionally, the interior of the vessel had not been cleaned, leaving the interior unmodified and the residue protected from contamination.
Other Worthy Stories of the Week
Volcano observatories around the world
Watch a bike disappear in 365 days Slow motion video.
Catching a comet death on camera
Tiny amounts of alcohol double worm’s lifespan. But why?
Ancient ‘tulip creature’ discovered
Helix Nebula in new colors
Native forest birds in Hawaii in unprecedented trouble
Scientists design solar cells that exceed the conventional light-trapping limit
Gaseous ring around young star raises questions
Archeologists find clues to Neanderthal extinction
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
Laelaps more vertebrate paleontology
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