Jul 04, 2022 07:00:00

It is pointed out that the 'sixth finger' of the giant panda has evolved for convincing reasons.

A giant panda that heals people with a lovely appearance. Like many mammals, it has five fingers on both its forelimbs and hindlimbs, but its forelimbs have bump-like protrusions that

can be used to grab bamboo by combining them with their fingers. It has been a long-standing mystery as to which process of evolution this 'sixth finger' was born, but the discovery of new fossils is unraveling the mystery of its unique shape.

Earliest giant panda false thumb suggests conflicting demands for locomotion and feeding | Scientific Reports
https://www.nature.com/articles/s41598-022-13402-y

Pandas gave bamboo the thumbs up at least six million years ago
https://phys.org/news/2022-06-pandas-gave-bamboo-thumbs-million.html

Who's Got Two Pseudothumbs and Loves Bamboo? This Panda Bear. --The New York Times
https://www.nytimes.com/2022/06/30/science/panda-thumb.html

Around 2015, paleontologist Xiaoming Wang and colleagues discovered an ancient bear fossil in a mine in southwestern China. Investigations have raised the possibility that this fossil belongs to the giant panda ancestor 'Ailurarctos,' which is believed to have inhabited around 7 to 6 million years ago.

The fossil, believed to be from Ailurarctos, also had a sixth finger, but it was clearly larger than that of the modern giant panda and stretched straight. Wang and his colleagues wondered, 'Why didn't this finger evolve more complicatedly?' I thought it would make more sense to evolve with a large, long finger that is easy to bend.

To this mystery, Wang et al. Established one hypothesis that 'there is a reason for the giant panda to walk.' As is well known, giant pandas are quadrupedal and always walk like stepping on their sixth finger. If your sixth finger gets too big, you can hurt the soles of your feet every time you walk. However, on the other hand, the sixth finger had to remain for the action of 'grabbing an object'. For this reason, the sixth finger did not evolve significantly, and on the contrary, it is thought that it settled down to the small protrusion as it is now.

'Eating with a firm bamboo stalk was probably the best way to consume a large amount of bamboo. Giant pandas have been around for many years, not big enough to get in the way, and strong enough to be useful. I've kept my fingers. '