
Opposable Thumb
by Pamela J. Hines (Science 23 Apr 2021:Vol. 372, Issue 6540, pp. 357) Hand bones of australopithecine hominid fossils dated to over 2 million years ago have a long, slender thumb that may have added dexterity. Karakostis et al. add muscle to the story of hand evolution with their analysis of torque at the thumb …