The human spine, a marvel of evolutionary engineering, has undergone significant transformations from our primate ancestors to modern humans. Unlike chimpanzees, whose spines connect with the skull at the back, human spines connect underneath the skull. This connection stabilizes the head during upright walking, a key feature of human evolution.
Recent advances by Harvard researchers have led to the first stem cell models of human spine development. This groundbreaking work paves the way for a deeper understanding of musculoskeletal and metabolic disorders, including conditions like congenital scoliosis, muscular dystrophy, and Type 2 diabetes. The study of the spine is crucial, as it plays a vital role in our ability to perform everyday activities like jumping, dancing, running, and climbing. As Edward Johnson noted, “Without a spine, our ability to move would be completely different.”
Comprising 33 bones separated by cartilaginous discs, the human spine is supported by ligaments and muscles. Its natural curvature, consisting of the lordotic cervical region, the kyphotic thoracic region, and the lordotic lumbar region, is essential for balance and mobility. The cervical vertebra, depicted in a life-size model with spinal cord and originating nerves, illustrates this intricate structure.
The Skeletal Biology and Biomechanics Lab focuses on understanding the evolution of the human body, particularly in terms of physical activity, and applying this knowledge to improve human health. This evolutionary anthropological perspective is vital for comprehending the spine’s development and functionality.
One fascinating aspect of spinal development is the segmentation clock in embryos, which leads to the formation of the spine’s vertebrae. A study by Harvard Medical School genetics professor Olivier Pourquié, whose lab discovered this mechanism, highlights its significance.
The human spine also ends with the coccyx, or tailbone, a remnant of our evolutionary past. While it no longer serves the same purpose as in tailed animals, it remains a crucial part of our spinal structure.
Recent research, including the creation of a new atlas of the cells in the human spinal cord, has shed light on spinal cord diseases like ALS. These studies are part of the broader Human Cell Atlas project, which aims to map every cell type in the human body, offering invaluable insights into the spinal cord’s complexity and function.
For more information on these topics, explore these resources:
Walking Upright,
Stem Cell Models of Human Spine Development,
Function of the Spine, and
Skeletal Biology and Biomechanics Lab.
