Gene mutation makes panda plant eater

According to American scientists a mutation in a taste gene caused pandas to stop eating meat. The gene is still active in humans and enables us to taste savoury flavours.
Researchers from the University of Michigan worked on the genome of the giant panda. They discovered that the animals have an inactive version of the gene Tas1r1. The animals are probably unable to taste meat because of this inactive gene and prefer to eat bamboo. The taste gene became inactive about 4.2 million years ago. Between 7 and 2 million years ago pandas stopped eating meat and switched to bamboo. This was already known from fossil records.
The researchers think the panda first switched to eating bamboo because climate change had made their prey extinct. Subsequently, the gene for savoury flavours became less important and stopped functioning. The result was that the panda lost its taste for meat and did not pick up hunting again once prey became available again. Today giant pandas eat bamboo almost exclusively. They are eating continuously. They have to eat 20 kilos of bamboo a day to get enough nutrients from it.
With respect to their teeth and digestive system giant pandas can still be considered meat eaters. They still eat meat when it is offered to them in captivity.