What do you think?
Rate this book


337 pages, Hardcover
First published November 11, 2019
Members of the human evolutionary line carry their body weight on two legs only. As the arms no longer play any role in bearing weight during locomotion, they are significantly shorter than the legs. The longer legs are the result of an elongation of the shinbones in particular. The head is balanced directly above the neck and is no longer supported by powerful neck muscles. The hole where the spinal cord enters the skull is therefore located underneath the skull instead of at the back of it. As the arms no longer restrict the chest cavity, which happens when apes walk on all fours, the human rib cage is broader than that of an ape. The shoulder blades move up and away from the sides of the body and are now located completely on the back. To cushion vertical impact, the spine is S-shaped. The pelvic girdle becomes shorter and wider, and the two broad bones at the tip of the pelvis form a bowl shape. That shortens the distance between the sacrum, the triangular bone at the bottom of the spine, and the hip joint, which lends more stability to the whole hip area. The musculature of the rear end bulks up to allow bipeds to straighten their hips and stand upright. The leg muscles bulk up as well. Heavier muscles, together with longer, and therefore heavier, leg bones lower the body’s center of gravity. For a more secure stance, the thighbones angle slightly inward so that knees end up directly beneath the body’s center of gravity. (p. 87)
However, paleoanthropology, the relatively young science of prehistoric humans and their ancestors, has not always been characterized by goal-oriented, self-critical research. It has also had its share of accidental discoveries, vanity-driven agendas, dazzling personalities, and unscrupulous frauds.Candid admissions establish trust.
Building tooth enamel is an energy-intensive process, so no mammal has more tooth enamel than it needs. Afropithecus's thick enamel, therefore, points to a change in diet. It was probably eating food that was harder and tougher.Böhme talks a bit about diet changes, ecological changes that influence diet changes, the advent of cooking with fire and it change in enamel for the more advanced hominins that didn't have to gnaw the tough fibers of meats and some plant matter.
Food that has been heated is also quicker and easier to digest and has more nutritional value than raw, and the amount of energy a person can extract from it increases enormously.