Births Chimpanzees also struggle with cramped conditions at birth
Not only humans, but also chimpanzees have to contend with tight spaces in the birth canal during birth. This finding from a recent study by the University of Zurich contradicts a previous theory on the course of human birth.
23.10.2024, 11:44
SDA
Birth in chimpanzees and other great apes is generally regarded as unproblematic due to their spacious pelvis and the small heads of the newborns, whereas human birth is the most complex and risky among mammals. This is according to a press release issued by the University of Zurich on Wednesday.
Using a three-dimensional virtual simulation of the birth process, a research team from the University of Zurich has now been able to show that the spatial conditions in the chimpanzee's pelvis are in fact just as confined as in humans. They also came to the conclusion that female chimpanzees also have a more spacious pelvis than males, and that the newborns are also secondary nestlings - similar to human babies, albeit less extreme.
Gradual development
Based on these parallels, the researchers propose the new hypothesis that the birth dilemma developed gradually over the course of evolution and became increasingly severe. This contradicts the previous theory that the long and difficult human birth came about abruptly with the enlargement of the brain in Homo erectus, according to the press release.
The increase in body size in the ancestors of the great apes made the pelvis stiffer, which limited the ability to stretch during birth. In early hominids, the upright gait led to a twisted birth canal, which required complex movements of the fetal head. This mechanism, and not the narrowness of the birth canal, is the main cause of the difficult birth in humans, it is said.
