An international collaborative research team such as Keio University that the beak of "Caledonian glass" that lives in New Caledonia Island in the South Pacific and catches insects using tools such as twigs has evolved into a special shape so that tools can be used. Found.It has been said that there is a suitable hand form in the background of humans' use of tools, but this discovery proves that it is the same for animals other than humans.The research results were published in the electronic version of the English scientific journal "Scientific Reports".
According to Keio University, the international collaborative research team used specimens of 10 species of crows including Caledonian glass and 1 species of fox, and compared the morphology of the head digitally converted into 3D by CT images.Generally, the lower beak of a crow is bent downward, but only the Caledonian glass was raised.As a result, the Caledonian glass beak faces the front of the face, extends straight, and the top and bottom mesh is flat.It was found that it was very suitable for grasping the tool with a close eye, and that the beak and the tool could be integrated and operated.
The international collaborative research team analyzed that the Caledonian glass beak had evolved into a shape suitable for the use of tools, so tools such as twigs were used.I think that the relationship between human tool use and the shape of the hand works as a common principle of evolution.
