The University of Osaka
Biological Anthropology Lab.
Faculty Members
Through the primates
Our behavior is physically determined by the anatomy and movement of muscles and skeletons of our body. It is also the result of an accumulation of modifications that have occurred in the body over 7 million years of human evolution. What are the derived characteristics of humans? Looking only at humans does not reveal the full picture. By observing the body anatomy and movements of our evolutionary neighbors, nonhuman primates, and clarifying the efficiency and performance of their movements, we are trying to elucidate the evolutionary process behind the acquisition of upright bipedal walking, fine hand control, and language by humans.
Takeshi Nishimura
Professor
Evolution of language: anatomy, physiology and biomechanics of primate vocalizations
I am currently researching the evolution of language, particularly the evolutionary process of the biological foundations of speech, the medium of language communication. Together with many collaborators, I am trying to clarify the characteristics of humans who acquired spoken language through a multifaceted approach that includes primate anatomy, speech physiology and behavioral experiments, acoustic analysis, numerical simulations, and electrophysiological experiments.
In addition, I am taking advantage of opportunities that arise from time to time to undertake a variety of research projects related to human evolution, such as simulation research on the physiological characteristics of the nasal cavity and research on the evolutionary process of monkeys through CT image analysis of fossil primates.
Tetsuya Shitara
Assistant Professor
Evolution of upright bipedalism in humans, biomechanics of locomotion in nonhuman primates
I am interested in the evolutionary process of upright bipedal walking, one of the most definitive characters of human beings, particularly the evolutionary changes of the gluteus medius muscle in anatomy and function. Upright bipedal walking is more laterally unstable than quadrupedal walking, in that there is a period when the entire body is supported by only one-side leg. The gluteus medius muscle is one of the elements that deal with this lateral instability. I use simulations using musculoskeletal models and analysis of muscle activity, to elucidate the mechanism that brought about the functional changes of the gluteus medius muscle.
2023 Japanese Society of Anthropology Young Members Conference Presentation Award, 2024 Osaka University Award (Young Faculty Division).
Shigehiro Miyachi
Visiting Associate Professor
Neuroanatomical study on neural circuits involved in the integrated control of vocalization and facial expression
At the Center for the Evolutionary Origins of Human Behavior, Kyoto University, he is dedicated to elucidating the structure and function of brain networks involved in behavioral decision-making and motor control. Specifically, using macaques, he conducts anatomical research on neural circuits related to motor and behavioral control. Through methods such as the electrophysiological techniques observing body movements in response to stimulation within the motor cortex and the neurotracing, he has clarified the neural circuits involved in the integration of movement and information processing, along with their functions. In recent years, he has identified the periaqueductal gray (PAG) region, a vocalization center, through vocalization observation using microelectrical stimulation. We are now using neurotracers to clarify the patterns of cortical input to this region. He will conduct behavioral experiments on the relationship between vocalization and facial expressions in primates and undertake anatomical studies using archived brain specimens.
Yoshihiko Nakano
Retirement in March 2025
Research on human evolution from the perspective of phylogenetic development of movement and morphology
Fossils provide direct evidence of the human evolutionary process. I have participated in fossil surveys in northern Kenya and excavated new fossils that are thought to be the common ancestor of humans and apes. Since fossils cannot be taken out of Kenya, I measured them and comparing their morphology at museums in Kenya.
Most fossil evidence is fragmentary, and is insufficient to provide sufficient information about evolution. Therefore, comparative studies using extant primates are being conducted in various fields. In order to understand the adaptations to the movement patterns of various primates, we focused on the movement of many primates, especially tree climbing movement, which is seen in all species, and conduct kinematic comparative analysis.