Unlike other animals, out thumb is opposable, which means that it has free movement and can be placed opposite the fingers of the same hand. This helps us to grip things securely and lets us do delicate jobs like threading a needle. Our grooved fingertips prevent smooth tings form slipping away. This movement of the hand, combined with the freely moving shoulder joint and the upright posture, gave our ancestors a development advantage: tools or weapons could be used for a specific purpose with great power.
No comments:
Post a Comment