The latest research comes!History of panda can be traced back to 6 million years ago

The giant panda belongs to the giant panda is different from its same brothers. It has many "stunts" that enables it to adapt to a life that specializes in bamboo. Among these stunts, the extra "thumb" of the giant panda can be said to be the most famous but also the most mysterious. In addition to most of the normal fingers on the forelimbos of the forelopstines of most mammals, giant pandas also have a strong increase in wrist bones, namely radial seed bone, acting as the sixth finger, forming a "thumb" that can be held to grasp bamboo.

Recently, the ancient vertebrates of the Chinese Academy of Sciences and the scientific research team of the Institute of Ancient Human Research and their peers published a paper sixth finger in the international journal "Scientific Report", namely the evolution of the "pseudo -thumb" evolution. The key pseudo -thumb and molars of panda panda, from the ancient spine center, the Yunnan Archeology Institute, and the joint organization of the Zhaotong Municipal Government in 2015, were scientifically excavated. The results of the study show that the beginning of the panda has the earliest increased radial seed bone and has formed the "thumb" function of the pair. However, since the late Chinese New Year, the panda's "thumb" has not further increased, because it must also take into account the load -bearing function of walking, and must not be abolished. The restrictions on the weight may be the main reason why the pseudo -thumbs of the panda have never evolved into a complete finger, but this humble "thumb" shows that the habit of eating bamboo specifically to eat bamboo was at least 7 million years ago. Essence

△ Yunnan Zhaotong Reservoir Ecological restoration on the right individual display the pseudo -thumb grip function, the left individual displayed walking attitude

Although the pseudo -pseudo thumb is very famous, it is just a very simple and small and flat structure, which has confused early anatomists. To understand the ins and outs of the pseudo -thumb, fossils are the most important evidence, but the earliest records of the previous record were only discovered in Shuanghe Cave in Guizhou about 10.2 ~ 49,000 years ago in the evening update of the world. If grabbing bamboo is the main function of this feature, because the seeds of mammals are easily extended in development, why did the giant panda not evolve a slender radial seed bone? The seed bone of the grip thumb is to grasp the bamboo more effectively? This question did not answer before, because the Panda-Grand Panda spectrum that was updated early than the evening of the world lacked relevant fossil evidence. This achievement released a new discovery of the Late Sino -Singapore Reservoir Location of the Zhaotong Basin in Yunnan. According to the earliest increased radial seed bone known as the first panda known, its pseudo thumbs showed the intermediate shape. Possible time and steps. Among the carnivores, the molars of the bear family are the most complicated because they also chew a lot of non -meat foods. Among the bear family, the panda's teeth mode is the most fine, and the folds have many very obvious tip of the tooth. With the assistance of the strong mandibular and temporal mandibular joints, it is conducive to chewing hard bamboo. The form of the panda's teeth has reached the complexity of modern giant pandas, and even more complicated. Has the panda started eating bamboo? It is another key evidence to help the pseudo -thumbs that hold the bamboo pole.

△ The anatomical structure of the panda (A, C) and the Panda (B, D) pseudo thumb

The grip of giant pandas is fundamentally different from human grasping. The radial seed bone forms a functional complex with the first palm and the boat moon bone through a fixed joint. Exercise in other fingers. This passive grip system is far less effective than the human active grasp system, but it is enough to provide the grabbing ability to eat bamboo for giant pandas. In addition, from the perspective of evolution, even if the radial seed bone initially only increased slightly, it can form a simple but useful grip function, which is moderately preventing bamboo from slipping from the fingers.

△ The comparison between the panda (B, D, E) and the original bear (A) and the human (C) hand

The longer fingers will definitely enhance the ability to grab the bamboo pole. So why did the puppet pseudo -thumbs not further stretched? Studies believe that the radial seed bone does not further extend, and it is a functional reconciliation between the pseudo -thumbs to grab the bamboo pole and bear the weight. Different from the toe -stroke of running carnivorous animals such as dogs, cats, and dumplings, obese bears are all semi -line, that is, when walking and rear feet when they walk. The strong extension of the radial seed bone is more conducive to grasping bamboo, but it inevitably conflict with long -distance walking, which will damage the dual function of the pseudo -thumb -the inner surface is used to grab and the outer surface for load. The further increase of any radial seed bone will lead to more significant protrusion on the palm surface, which will interfere with walking. In layman's terms, it will be stubborn. Therefore, the existing giant panda bent inwardly into hook -shaped to balance the function room through the end of the pseudo -thumb. Among the existing bears, only a giant panda has a large meat pad to cushion the radial seed bone, indicating that the load -bearing function of this bone is important.

△ Grand Panda grabs and chews bamboo

Panda transitions from extensive omnivorous to eating bamboo, and it is reasonable to make multiple changes on the basis of anatomy, physiology, and genetics.However, even after at least 6 million years of focusing on the history of eating bamboo, these changes are still limited, mainly focusing on feeding skills, and the giant panda's digestive system is still the configuration of carnivores.After the late Chinese and Sino -Singaporees, the fact that the pseudo -thumbs of the Panda family did not further extend, showing that they have gained enough grip to deal with bamboo.In other words, it is enough to seize a bamboo pole or a bamboo, and at the same time, it is necessary to walk with a obese body.(CCTV reporter Shuaijunquan)

Source: CCTV News

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