Tag Archives: darwin

Carnivorous Plant Throws Out ‘Junk’ DNA

The newly sequenced genome of the carnivorous bladderwort plant contradicts the notion that vast quantities of noncoding DNA are crucial for complex life. UA researchers helped solve the puzzle by providing specialized genome analyses and computational software.

Genes – the bits of DNA that code for proteins – make up about 2 percent of the human genome. The rest consists of a genetic material known as noncoding DNA, and scientists have spent years puzzling over why this material exists in such voluminous quantities. (more…)

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Deep in Texas, a plant-eating feathered dinosaur reemerges

A recently identified feathered dinosaur found deep in West Texas reinforces an emerging view that creatures like it were more diverse and widespread in North America than previously thought, according to a new study.

The species — a turkey-sized herbivore called Leptorhynchos gaddisi — belongs to a broader group of bird-like dinosaurs characterized by toothless beaks and long, slender claws, said researchers, who analyzed fossils found near Big Bend National Park at a site dating to about 75 million years ago. (more…)

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Gardener’s Delight Offers Glimpse into the Evolution of Flowering Plants

The Pink Double Dandy peony, the Double Peppermint petunia, the Doubled Strawberry Vanilla lily and nearly all roses are varieties cultivated for their double flowers.

The blossoms of these and other such plants are lush with extra petals in place of the parts of the flower needed for sexual reproduction and seed production, meaning double flowers – though beautiful – are mutants and usually sterile.

The genetic interruption that causes that mutation helped scientists in the 1990s pinpoint the genes responsible for normal development of sexual organs stamens and carpels in the plant Arabidopsis thaliana, long used as a plant model by biologists. (more…)

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Biologists Turn Back the Clock to Understand Evolution of Sex Differences

Battles of sexes shown to spur adaptive sex differences

Sex differences account for some of the most of the spectacular traits in nature: the wild colours of male guppies, the plumage of peacocks, tusks on walruses and antlers on moose. Sexual conflict – the battle between males and females over mating – is thought to be a particularly potent force in driving the evolution of traits that differ in males and females.

However, the genetic processes responsible for producing such traits are not well understood, nor how they evolved from their simpler less elaborate ancestral forms. We tend to assume that each tiny step in evolution is an advantage. But are they really? (more…)

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Scientists Trace Evolutionary History of What Mammals Eat

*Feeding habits haven’t always been what they are today*

The feeding habits of mammals haven’t always been what they are today, particularly for omnivores.

Some groups of mammals almost exclusively eat meat–take lions and tigers and other big cats as examples.

Other mammals such as deer, cows and antelope are predominantly plant-eaters, living on a diet of leaves, shoots, fruits and bark. (more…)

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UChicago Launches Search for Distant Worlds

Since 1995, scientists have discovered approximately 600 planets around other stars, including 50 planets last month alone, and one that orbits two stars, like Tatooine in Star Wars. Detection of the first Earthlike planet remains elusive, however, and now the University of Chicago joins the search with the addition of Jacob Bean and Daniel Fabrycky to the faculty.

“I can’t imagine a more profound impact on humanity than the discovery that there are other Earthlike worlds or that we are not alone,” said Rocky Kolb, the Arthur Holly Compton Distinguished Service Professor in Astronomy & Astrophysics and department chairman. (more…)

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Biodiversity improves water quality in streams through a division of labor

ANN ARBOR, Mich.— Biologically diverse streams are better at cleaning up pollutants than less rich waterways, and a University of Michigan ecologist says he has uncovered the long-sought mechanism that explains why this is so.

Bradley Cardinale used 150 miniature model streams, which use recirculating water in flumes to mimic the variety of flow conditions found in natural streams. He grew between one and eight species of algae in each of the mini-streams, then measured each algae community’s ability to soak up nitrate, a nitrogen compound that is a nutrient pollutant of global concern. (more…)

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