Titel på undersøgelse:

The Evolution of the Human Pelvis: Changing Adaptations to Bipedalism, Obstetrics, and Thermoregulation.

Forfattere: Gruss, Laura T., and Daniel Schmitt. | År: 2015 | Kapitel:

Fossiloptegn viser, hvordan menneskets bækken har udviklet sig under forskellige krav til bevægelse, fødsel og varmeafgivelse. De tidlige homininer havde et bredt bækken, der tilpassede sig bipedal gang. For cirka 200.000 år siden opstod det moderne smalle bækken hos Homo sapiens, hvilket muliggør større hjernestørrelser og bedre termoregulering, samtidig med at det bevarer evnen til at gå effektivt.

Hele abstrakt på originalsprog:

The fossil record of the human pelvis reveals the selective priorities acting on hominin anatomy at different points in our evolutionary history, during which mechanical requirements for locomotion, childbirth and thermoregulation often conflicted. In our earliest upright ancestors, fundamental alterations of the pelvis compared with non-human primates facilitated bipedal walking. Further changes early in hominin evolution produced a platypelloid birth canal in a pelvis that was wide overall, with flaring ilia. This pelvic form was maintained over 3–4 Myr with only moderate changes in response to greater habitat diversity, changes in locomotor behaviour and increases in brain size. It was not until Homo sapiens evolved in Africa and the Middle East 200 000 years ago that the narrow anatomically modern pelvis with a more circular birth canal emerged. This major change appears to reflect selective pressures for further increases in neonatal brain size and for a narrow body shape associated with heat dissipation in warm environments. The advent of the modern birth canal, the shape and alignment of which require fetal rotation during birth, allowed the earliest members of our species to deal obstetrically with increases in encephalization while maintaining a narrow body to meet thermoregulatory demands and enhance locomotor performance.