Thursday, August 31, 2006

Dolphins are dim-wits?

Scientist says dolphins are dim-wits

'Dolphins may have big brains but a South African-based scientist says lab rats and even goldfish can outwit them. Paul Manger of Johannesburg's University of the Witwatersrand says the super-sized brains of dolphins, whales and porpoises are a function of being warm-blooded in a cold water environment and not a sign of intelligence.'

'Brains, he says, are made of neurons and glia. The latter create the environment for the neurons to work properly and producing heat is one of glia's functions.'

'"Dolphins have a superabundance of glia and very few neurons ... The dolphin's brain is not made for information processing it is designed to counter the thermal challenges of being a mammal in water," Manger said.'

'"Dolphins can actually chain up to 16 stimulus response events, but this is indicative of good trainers and not intelligent animals. Stimulus-response conditioning is thought to be a low level of intelligent behaviour," Manger said.'

'Manger also points to the tuna industry, which under consumer pressure has gone to great lengths to prevent dolphins from being caught and killed by accident in nets.'

'"If they were really intelligent they would just jump over the net because it doesn't come out of the water," he said.'