Tag Archives: charles darwin

Brüllaffen: Tiefe Stimme, kleine Hoden

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.

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Predators and isolation shape the evolution of ‘island tameness,’ providing conservation insights

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…)

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Florida Lizards Evolve Rapidly, Within 15 Years and 20 Generations

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…)

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Researchers Reveal How Electric Fish Evolved Their Shocking Skills Independently at Six Different Times

AUSTIN, Texas — New research demonstrates that the six electric fish lineages, all of which evolved independently, used essentially the same genes and developmental and cellular pathways to make an electricity-generating organ for defense, predation, navigation and communication. (more…)

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Scholars and scientists explore factors underlying serendipitous discoveries

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…)

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Back to the Future: A New Science for a Changing Planet

In a world that is changing on a global scale and faster than ever before, science should rediscover its roots of observing the natural world unimpeded by the strict protocols of experimental manipulations, UA ecologist Rafe Sagarin and co-author Aníbal Pauchard suggest in their book, “Observation and Ecology.”

Mars rover Curiosity is doing it. School children strolling through the woods with binoculars are doing it. Charles Darwin was doing it. Observing the natural world around them was how the early naturalists started what would later become known as ecology – the science of how living things interact, depend on each other and how their habitats and communities change over time.

In their book, “Observation and Ecology,” ecologists Rafe Sagarin and Aníbal Pauchard make the case that if scientists are to tackle the enormously complex problems the world is facing, researchers and funding agencies have to leave their comfort zone of well-controlled experimental manipulations. (more…)

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UCLA Biologists Reveal Potential ‘Fatal Flaw’ In Iconic Sexual Selection Study

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…)

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Tortoise Species Thought to Be Extinct Still Lives, Genetic Analysis Reveals

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…)

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