Athro, Limited Biology Evolution The Panda's Thumb

Lesser Panda Taronga Park Zoo

The relationship of the giant panda to other animals in the Carnivora has been somewhat controversial. Davis firmly said, based on anatomy, that giant pandas are bears. Some workers, however, have argued that the giant panda is more closely related to raccoons than bears, others have placed it in a group of their own within a larger group of carnivorans (the Arctoidea) containing both bears and raccoons. There was a flurry of argument in the late 1980s generated by comparison of hemoglobins molecules that suggested that the giant panda and the lesser panda (figured to the right) were closely related, and were related to raccoons rather than bears. Several different lines of argument now clearly point to giant pandas being most closely related to bears.

In addition to Davis' arguments about anatomy, panda hair (Dziurdzik et al), and lots of molecular studies say giant panda is a bear.

1. Anatomy looks like a bear ( Davis, 1964). (Bones and muscles and stuff) - but a bear that eats bamboo. The giant panda has lots of weird specializations, including an inflated gut for churning bamboo to try to get some nutrition out of it.
2. Particular little bits of it look like bear. Put panda fur under the microscope and it looks like bear fur (Dziurdzik et al).
3. Chromosomes - rearrangements unique, could be made from bear, couldn't be made from raccoon. (O'Brien et al 1985)
4. Hemoglobin
   • first look said not bear (Tagle et al 1986; Braunitzer & Hofmann 1987)
   • sequence says bear (Hashimoto et al 1993)
5. lots of gene sequences - all say bear (Ledje and Arnason, 1996; Zhang and Ryder, 1994; Vrana et al, 1994).
6. cladistics on anatomy says bear (Vrana et al, 1994 p.).