Roger Highfield, "Pandas give thumbs-up to theory of evolution"(2005)

Pandas give thumbs-up to theory of evolution
> <span class="storyby">By Roger Highfield, Science Editor<span>
> <span class="filed">(Filed: 2912/2005)

The riddle of the panda's thumb - one of the classic stories used to illustrate evolution - is even more remarkable than scientists had thought, according to a study published this week.

	A reconstruction of a puma-sized red panda ancestor

In 1980, the late and highly-regarded evolutionary biologist Stephen Jay Gould celebrated the concept of contingency in evolution with the development of the giant panda's false thumb.

In The Panda's Thumb, a book of essays, Gould explained that the so-called thumb that allows the panda to strip the leaves off bamboo is really part of the wrist (the sesamoid bone) and evolved for this use because the panda lacks an opposable digit.

He noted that "odd arrangements and funny solutions are the proof of evolution - paths that a sensible God would never tread but that a natural process. . . follows perforce." Evidence published on Tuesday in the Proceedings of the National Academy of Sciences shows that the thumb of a second kind of panda, the raccoon-like red panda, provides what researchers claim is "an even more striking example of how evolution works opportunistically".

A Spanish team has uncovered the earliest evidence of a "false thumb" in the panda fossil record, a finding that also clarifies the evolution of, and relationship between, the distantly related red and giant pandas. Both pandas share the unique false thumb. But the thumbs are structurally different and it is likely that they evolved independently.

Paws: Ailuropoda melanoleuca and Simocyon batalleri

The researchers report a false thumb in previously unknown fossils of the red panda ancestor Simocyon batalleri, a puma-sized, tree-dwelling carnivore. "The discovery that this animal had a "false thumb" throws new light on the evolution of this feature in both the giant panda (Ailuropoda melanoleuca) and the red panda (Ailurus fulgens) lineages," said the team.

21 December 2005: Keep the divine out of biology lessons, judge rule