Elephants are evolving smaller tusks

The average tusk size of African elephants has halved since the mid-19th century. A similar effect has been spotted in the Asian elephant population in India.

Researchers say it is an example of Darwinism in action, caused by the mass slaughter of dominant male elephants - but whereas evolution normally takes place over thousands of years, these changes have occurred within 150 years.

Zoologists at Oxford University fear that poaching and hunting of the largest male elephants, which also have the largest tusks, has changed the natural breeding behaviour of these animals. Their research has shown that the hunting of these large males for their ivory allows smaller males with shorter tusks to produce more calves. Over time the average tusk size decrease

Source: Telegraph

Scientists map elephant evolution

Scientists say they have calculated the date at which the African and the Asian elephant went their separate ways.

The two elephant species diverged from a common ancestor some 7.6 million years ago, experts working in the US, Germany and Switzerland say.

They came to their conclusion after comparing a genetic analysis of the two species with material derived from the extinct woolly mammoth and mastodon.

Study: Soft tissue in T.rex resembles that of hen

T. rex was no chicken.

But scientists say soft tissue recovered from inside the leg bone of a 68-million-year-old Tyrannosaurus rex most closely resembles that of a modern hen.

This is the first time dinosaur protein has ever been sequenced. The feat, described in Friday's edition of the journal Science, means that researchers now have a new way to learn how ancient creatures are related to modern animals.

The discovery also bolsters the theory that birds descended from dinosaurs, and suggests that a T. rex drumstick might have tasted like chicken.

"What we knew, based on bone shape, was that dinosaurs are closely related to birds," said Mary Schweitzer of North Carolina State University and lead author on one of the Science papers.

"The similarity to chicken is definitely what we would expect."

The T. rex femur was discovered at the Hell Creek Formation in Montana in 2003, buried deep beneath the surface of a sandstone outcrop. Paleontologists had to break the leg into pieces to get it into the helicopter that was ferrying finds away from the site.

Schweitzer was able to isolate soft material from the hollow cavity of the bone. It seemed to contain blood vessels and cells.

Dogs that Changed the World

It is the epic story of one of the most amazing evolutionary journeys ever taken by a species. Thousands of years ago, as humans began to settle in villages, the wolf emerged from the wild and made the startling leap to "man's best friend." Once domesticated, dogs would accompany human cultures down through the centuries and to the far corners of the world.

Human Pubic Lice Acquired From Gorillas Gives Evolutionary Clues

Humans acquired pubic lice from gorillas several million years ago, but this seemingly seedy connection does not mean that monkey business went on with the great apes, a new University of Florida study finds.

Rather than close encounters of the intimate kind, humans most likely got the gorilla's lice from sleeping in their nests or eating the giant apes, said David Reed, assistant curator of mammals at the Florida Museum of Natural History on the UF campus, one of the study's authors. The research is published in the current edition of the BMC Biology journal.

"It certainly wouldn't have to be what many people are going to immediately assume it might have been, and that is sexual intercourse occurring between humans and gorillas," he said. "Instead of something sordid, it could easily have stemmed from an activity that was considerably more tame."

About 3.3 million years ago, lice found on gorillas began to infest humans, Reed said. That they took up residence in the pubic region may have coincided with humans' loss of hair on the rest of their bodies and the lack of any other suitable niche, he said.

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