You are looking at an artist's reconstruction of the fossil species Carpolestes simpsoni, which belongs to a group of animals th
ought to be an ancestor to modern primates, called plesiadapiforms. Plesiadapiforms lack most of the morphological variation characteristic of modern primates. However, C. simpsoni had an opposable big toe with a flat nail instead of the claws present on its other digits. Its hands and feet were well adapted for grasping and moving around on small branches, but they lacked the foot structure associated with leaping. Its eyes were located on the sides of the head and it did not have binocular vision. The dentition of C. simpsoni suggests that it probably ate fruit. Given this recent plesiadapiform fossil discovery, which of the following hypotheses is most consistent with the evolution of primates? A) Grasping hands and feet with flat nails instead of claws all evolved together to facilitate leaping from branch to branch.
B) Binocular stereoscopic vision, grasping hands and feet, and nails on the toes and fingers all co-evolved to enhance visual predation on insects in the terminal branches of trees.
C) Grasping hands and feet allowed early primates to exploit fruit, flowers, and nectar in the terminal branches of angiosperms. Later, binocular stereoscopic vision evolved as an adaptation to predation on insects.
D) Binocular stereoscopic vision and grasping hands and feet evolved together as adaptations for exploiting new food sources in angiosperms.
B) Binocular stereoscopic vision, grasping hands and feet, and nails on the toes and fingers all co-evolved to enhance visual predation on insects in the terminal branches of trees.
Explanation:
A characteristic of the primates, when they evolved was the replacement of the claws by ones, the binocular vision, which generated these two characteristics the option to see and take better the insects and fruit in high branches
There are two large ovoid organs called the thalamus, which form most of the lateral walls of the third ventricle of the brain. A variety of receptors transmit signals from the thalamus to the cerebral cortex. Thalamus is anatomically situated adjacent to the midline third ventricle in the brain.