Tag Archives: evolution

Birdsong Bluster may Dupe Strange Females, But It Won’t Fool Partners

Male birds use their song to dupe females they have just met by pretending they are in excellent physical condition.

Just as some men try to cast themselves in a better light when they approach would-be dates, so male birds in poor condition seek to portray that they are fitter than they really are. But males do not even try to deceive their long-term partners, who are able to establish the true condition of the male by their song.

Researchers at the University of Exeter’s Cornwall Campus studied zebra finches to establish how trustworthy birdsong was in providing honest signals about the male’s value as a mate. Singing is a test of the condition of birds because it uses a lot of energy. Fit and healthy birds are thought to be able to sustain a high song rate for longer, making them more attractive to females. (more…)

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Asteroid that Killed the Dinosaurs also Wiped out the ‘Obamadon’

The asteroid collision widely thought to have killed the dinosaurs also led to extreme devastation among snake and lizard species, according to new research — including the extinction of a newly identified lizard Yale and Harvard scientists have named Obamadon gracilis.

“The asteroid event is typically thought of as affecting the dinosaurs primarily,” said Nicholas R. Longrich, a postdoctoral associate with Yale’s Department of Geology and Geophysics and lead author of the study. “But it basically cut this broad swath across the entire ecosystem, taking out everything. Snakes and lizards were hit extremely hard.” (more…)

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Space Life

NASA funds astrobiology research by Delaware Biotechnology Institute scientist

Does life exist anywhere else in the universe? That’s the type of broad but poignant question NASA likes to ask, according to Chandran Sabanayagam, associate scientist in the Bioimaging Center at the Delaware Biotechnology Institute (DBI). And he would know, because he’s preparing to help answer it.

NASA will receive $100 billion from the federal government over the next five years to assure America is number one in space exploration, according to Astrobiology.com. As part of its push to seek new partnerships and broaden its vision, NASA is offering grants to people conducting transformational science. With this opportunity, Sabanayagam is merging his love of physics and biology. (more…)

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Grand Canyon as Old as the Dinosaurs, Suggests New Study Led by CU-Boulder

An analysis of mineral grains from the bottom of the western Grand Canyon indicates it was largely carved out by about 70 million years ago — a time when dinosaurs were around and may have even peeked over the rim, says a study led by the University of Colorado Boulder.

The new research pushes back the conventionally accepted date for the formation of the Grand Canyon in Arizona by more than 60 million years, said CU-Boulder Assistant Professor Rebecca Flowers. The team used a dating method that exploits the radioactive decay of uranium and thorium atoms to helium atoms in a phosphate mineral known as apatite, said Flowers, a faculty member in CU-Boulder’s geological sciences department. (more…)

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BOSS Quasars Unveil a New Era in the Expansion History of the Universe

Berkeley Lab scientists and their Sloan Digital Sky Survey colleagues use quasars to probe dark energy over 10 billion years in the past

BOSS, the Baryon Oscillation Spectroscopic Survey, is mapping a huge volume of space to measure the role of dark energy in the evolution of the universe. BOSS is the largest program of the third Sloan Digital Sky Survey (SDSS-III) and has just announced the first major result of a new mapping technique, based on the spectra of over 48,000 quasars with redshifts up to 3.5, meaning that light left these active galaxies up to 11.5 billion years in the past.

“No technique for dark energy research has been able to probe this ancient era before, a time when matter was still dense enough for gravity to slow the expansion of the universe, and the influence of dark energy hadn’t yet been felt,” says BOSS principal investigator David Schlegel, an astrophysicist in the Physics Division of the U.S. Department of Energy’s Lawrence Berkeley National Laboratory (Berkeley Lab). “In our own time, expansion is accelerating because the universe is dominated by dark energy. How dark energy effected the transition from deceleration to acceleration is one of the most challenging questions in cosmology.” (more…)

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Exhaustive Family Tree for Birds Shows Recent, Rapid Diversification

A Yale-led scientific team has produced the most comprehensive family tree for birds to date, connecting all living bird species — nearly 10,000 in total — and revealing surprising new details about their evolutionary history and its geographic context.

Analysis of the family tree shows when and where birds diversified — and that birds’ diversification rate has increased over the last 50 million years, challenging the conventional wisdom of biodiversity experts.

“It’s the first time that we have — for such a large group of species and with such a high degree of confidence — the full global picture of diversification in time and space,” said biologist Walter Jetz of Yale, lead author of the team’s research paper, published Oct. 31 online in the journal Nature. (more…)

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Cambrian Fossil Pushes Back Evolution of Complex Brains

Complex brains evolved much earlier than previously thought, as evidenced by a 520-million-year-old fossilized arthropod with remarkably well-preserved brain structures.

The remarkably well-preserved fossil of an extinct arthropod shows that anatomically complex brains evolved earlier than previously thought and have changed little over the course of evolution. According to University of Arizona neurobiologist Nicholas Strausfeld, who co-authored the study describing the specimen, the fossil is the earliest known to show a brain.

The discovery will be published in the Oct. 11 issue of the journal Nature. (more…)

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