Skull Evolution Challenges Old Theories

Researchers from the Chinese Academy of Sciences and New York University opened new details about the origin of the two-legged gait of a person. They studied the skulls of fossils Monkeys of Lufengpithec, which are 6 million years old. Their focus was on the bone structure of the inner ear, which they scanned using three-dimensional computed tomography.

The inner ear, located between the brain and the outer ear, plays a crucial role in maintaining balance and orientation in space. This, in turn, affects the method of movement of mammals. The size and shape of the semicircular channels that make up part of this structure correlate with how monkeys and humans move.

A new study suggests a three-stage development of a two-legged gait in humans. At the first stage, early monkeys moved through trees, similar to modern gibbons. In the second stage, the last common ancestor of humans and monkeys, which resembled Lufengpithec in motility, used a combination of climbing, hanging on forelimbs, two-legged walking on trees, and four-legged walking on the ground. It was from this wide range of movement methods that the human bipedal gait developed.

Previous studies on monkey movement evolution mainly focused on comparing limb bones, shoulders, pelvis, and spine. However, the variety of movement methods in modern monkeys and the lack of complete fossils made it challenging to create a clear understanding of the origin of human bipedal gait.

The discovery of Lufengpithec skulls found in the Yunnan province of China in the early 1980s provided scientists with an opportunity to explore the evolution of movement from a different perspective. The use of three-dimensional scanning technologies allowed them to virtually reconstruct the bone channels of the inner ear and compare them with scans of other modern and fossil monkeys, as well as humans from Asia, Europe, and Africa.

Analyses revealed that early monkeys shared a set of movement methods that serve as the precursor to human bip