Friday, June 1, 2007

Did upright walking start in trees?

WASHINGTON - Maybe walking upright on two legs isn't such a defining human feature after all. Scientists who spent a year photographing orangutans in the rain forest say the trait probably evolved in ancient apes navigating the treetops long before ancestors of humans climbed to the ground - a hypothesis that contradicts science museums the world over.

Guesser: Robin Crompton of the University of Liverpool

Saturday, May 19, 2007

The Panda’s Thumb has Evolved … Twice!

"It seems that, whereas the false thumb of the giant panda probably evolved for manipulating bamboo, the false thumbs of the red panda and of S. batalleri more likely evolved as an aid for arboreal locomotion, with the red panda secondarily developing its ability for item manipulation and thus producing one of the most dramatic cases of convergence among vertebrates."

Guesser: Manuel J. Salesa, Departamento de Paleobiología

Fossils prove that birds evolved from dinosaurs

The fossils, which were unearthed in the Liaoning province in China, date back more than 120 million years and offer, according to Currie, conclusive proof that birds evolved from dinosaurs, a theory that has been hotly contested for more than 20 years. He said the feathers on the dinosaurs probably evolved for warmth, suggesting that some of the animals may have been warm-blooded.

Guesser: Phillip Currie, Royal Tyrrell Museum, Paleontology, Canada

Whales boast the brain cells that 'make us human'

Now it has been discovered that some whales also have spindle neurons – specialised brain cells that are involved in processing emotions and helping us interact socially. Hof and van der Gucht suggest that whales probably evolved the spindle cells completely independently of humans and apes – a process called convergent evolution. Moreover, they probably evolved them as long as 30 million years ago, twice as long ago as humans and apes.

Guessers: Patrick Hof of the Mount Sinai School of Medicine in New York

Human Gland Probably Evolved From Gills

The human parathyroid gland, which regulates the level of calcium in the blood, probably evolved from the gills of fish, according to researchers from King's College London. Professor Anthony Graham and Dr Masataka Okabe suggest that the gills of ancestral marine creatures, which were used to regulate calcium levels, were internalised rather than lost when land-living, four-limbed animals the tetrapods evolved.

Guesser: Professor Anthony Graham and Dr Masataka Okabe, King's College London

Gene clue to how eating a lot less could extend life

Pha-4 is the first gene to be exclusively linked to extending lifespan in response to calorie restriction in animals. Prof Dillin speculated that pha-4, which has an analogue in mice and humans with the Foxa family of genes, probably evolved to protect animals when food was scarce.

Guesser: Andrew Dillin, of the Salk Institute for Biological Studies in California