Einzigartiges Zungenbein lässt Männchen mächtiger erscheinen
Brüllaffen sind nach ihren beeindruckenden Rufen benannt. Für diese Fähigkeit sind die langen Stimmbänder und ein einzigartiges Zungenbein verantwortlich, das Männchen größer und mächtiger erscheinen lässt als sie wirklich sind. Ein internationales ForscherInnenteam unter Beteiligung von Kognitionsbiologen um Tecumseh Fitch von der Universität Wien hat herausgefunden, dass jene Brüllaffen mit den tiefsten Stimmen für diese einen hohen Preis bezahlen: Spezies mit einem größeren Zungenbein haben kleinere Hoden.
ANN ARBOR — Charles Darwin noted more than 150 years ago that animals on the Galapagos Islands, including finches and marine iguanas, were more docile than mainland creatures. He attributed this tameness to the fact that there are fewer predators on remote islands. (more…)
AUSTIN, Texas — Scientists working on islands in Florida have documented the rapid evolution of a native lizard species — in as little as 15 years — as a result of pressure from an invading lizard species, introduced from Cuba.
After contact with the invasive species, the native lizards began perching higher in trees, and, generation after generation, their feet evolved to become better at gripping the thinner, smoother branches found higher up. (more…)
What do Velcro, Tang, penicillin, the structure of DNA and the World Wide Web have in common?
They all involved serendipitous discoveries—chance discoveries made by alert, curious scientists who were looking for other things when they happened across a fortuitous finding. Rather than ignoring their accidental discoveries, these curious, open-minded scientists harnessed their luck. “Chance favors only the prepared mind,” as Louis Pasteur put it. (more…)
A classic study from more than 60 years ago suggesting that males are more promiscuous and females more choosy in selecting mates may, in fact, be wrong, say life scientists who are the first to repeat the historic experiment using the same methods as the original.
In 1948, English geneticist Angus John Bateman published a study showing that male fruit flies gain an evolutionary advantage from having multiple mates, while their female counterparts do not. Bateman’s conclusions have informed and influenced an entire sub-field of evolutionary biology for decades.
“Bateman’s 1948 study is the most-cited experimental paper in sexual selection today because of its conclusions about how the number of mates influences fitness in males and females,” said Patricia Adair Gowaty, a distinguished professor of ecology and evolutionary biology at UCLA. “Yet despite its important status, the experiment has never been repeated with the methods that Bateman himself originally used, until now. (more…)
Dozens of giant tortoises of a species believed extinct for 150 years may still be living at a remote location in the Galápagos Islands, a genetic analysis conducted by Yale University researchers reveals.
The analysis, published Jan. 9 in the journal Current Biology, suggests that direct descendants of at least 38 purebred individuals of Chelonoidis elephantopus live on the volcanic slopes of the northern shore of Isabela Island — 200 miles from their ancestral home of Floreana Island, where they disappeared after being hunted by whalers. (more…)
*Bacterial cells have gene mutations that allow them to ‘stick’ to the devices*
New research suggests that some patients develop a potentially deadly blood infection from their implanted cardiac devices because bacterial cells in their bodies have gene mutations that allow them to stick to the devices.
Geoscientists were the major contributors to the finding.
Proceedings of the National Academy of Sciences published the study results online this week. (more…)
A NASA-led research team has confirmed what Walt Disney told us all along: Earth really is a small world, after all.
Since Charles Darwin’s time, scientists have speculated that the solid Earth might be expanding or contracting. That was the prevailing belief, until scientists developed the theory of plate tectonics, which explained the large-scale motions of Earth’s lithosphere, or outermost shell. Even with the acceptance of plate tectonics half a century ago, some Earth and space scientists have continued to speculate on Earth’s possible expansion or contraction on various scientific grounds.
Now a new NASA study, published recently in Geophysical Research Letters, has essentially laid those speculations to rest. Using a cadre of space measurement tools and a new data calculation technique, the team detected no statistically significant expansion of the solid Earth. (more…)
