Gizmorama - July 9, 2014

Good Morning,

Are you left-handed? If so you make up ten percent of the population. For years, scientists have debated whether genetics are responsible for southpaws. Now, researchers have discovered some interesting developments for fellow lefties.

Learn about this and more interesting stories from the scientific community in today's issue.

Until Next Time,
Erin

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*-- Researchers say hormonal mechanism responsible for left-handedness --*
VIENNA (UPI) - The vast majority of humans are right-handed. Only about ten percent are left-hand dominant. But what causes the ten percent to prefer their opposite set of digits? Scientists have long traded theories on the matter and argued whether genetics are at play. Recently, in a survey of handedness involving 13,000 Germans and Austrians, researchers found that male southpaws are slightly more likely to be born in November, December and January than other months -- proof, they say, of a hormonal mechanism at work. The study was led by psychologist Ulrich Tran, a researcher at the University of Vienna, in Austria; the study was published this week in the scientific journal Cortex. "Presumably, the relative darkness during the period November to January is not directly connected to this birth seasonality of handedness," said Tran. "We assume that the relative brightness during the period May to July, half a year before, is its distal cause." Tran and his colleagues say their new research confirms an earlier theory, proffered in the 1980s by American neurologists Norman Geschwind and Albert Galaburda. They hypothesized that testosterone levels were essential in tipping the scales that determine handedness. Most right-handed people are left-brain dominant, and left-handed are right-brain dominant. And testosterone has been shown to delay the development of the left brain hemisphere during embryonic stages. Thus, Geschwind and Galaburda concluded, heightened testosterone levels may enable a preference for the right side of the brain and the left hand. The theory remains controversial, but Tran and his colleagues say the prevalence of left-handedness in winter babies corroborates the now-decades-old logic. Winter babies are conceived in spring, and in their earliest embryonic stages during summer, increased daylight hours can lead to heightened levels of testosterone in women. Excited as Tran and his study co-authors are, the researchers acknowledge more research is needed determine "the exact way of causation."


*---- Fossils reveal largest bird to ever grace the skies ----*
CHARLESTON, S.C. (UPI) - The shadow of a Pelagornis sandersi -- the largest bird species to ever take to the skies -- flying overhead, would offer a momentary shade for a few dozen people below. Some might even mistake the shadow for that of an airplane. The Pelagornis sandersi, which has been extinct for a few million years, would have cast such an impressive shadow because its wing span stretched some 24 feet -- nearly the size of a small prop plane. The newly confirmed species is named for Charleston Museum curator Albert Sander, who discovered the bird's remains some 30 years ago as he surveyed the lands which were to become the Charleston International Airport. But until now, the fossil was just that, nothing more than a single fossil -- unconfirmed as the evidence of a new giant bird species. That has changed thanks to paleontologist Daniel Ksepka, the curator of who rediscovered the bones of Pelagornis sandersi. Kspecka detailed the impressive specimen in the latest issue of the Proceedings of the National Academy of Sciences. He claims the fossils indicate that the ancient specimen as at least twice as the size of today's largest flying bird, the Royal Albatross. "This is pushing the boundary of what we know about avian size," he said, "and I'm very confident that the wingspan is the largest we've seen in a bird capable of flight." Not only was Pelagornis sandersi nearly as big as a prop plane, its behavior was very much like a small sea planet -- preferring to stick to the ocean. Twenty-five million years ago, when Pelagornis sandersi reigned, Charleston was underwater. "Pelagornis sandersi could have traveled for extreme distances while crossing ocean waters in search of prey," Ksepka said. The bird -- which likely took off not by flapping its heavy wings but by running down hill and using the uplift of the ocean winds to take flight (kind of like a hang glider) -- could soar for miles without flapping its giant wings. "The long wings would have been cumbersome [on land] and it would have probably spent as little time as possible walking around," Ksepka explained. Ksepka and his fellow scientists say they want to do more research to figure out why the species, which outlived the dinosaurs, eventually went extinct.

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