Today’s lecture covered the complexities of how we evolved to be bipedal hominins. The three major features of hominins are bepedal locamotion, big brains, and tool making, all of which evolved in a mosaic fashion over a long period of time. I asked my students which theory of bipedalism they preferred the most – 1) provisioning/carrying, 2) energy efficiency, 3) thermoregulatory, 4) dietary range, and/or 5) sexual selection for males who could provide resources. I reviewed how each of these models works and what pressures were acting on hominins during their evolution away from our last common ancestor about 7 million years ago. The students were really compelled by the provisioning and carrying model, which claims we became bipedal so that we could efficiently carry goods around and bring them back to a homebase. Surprisingly, none were too taken with the thermoregulatory model, which is a well supported theory for what drove us to walk upright. The point of this lecture was to demonstrate how complicated evolution and adaptation can be – I presented a fairly simple example on Wednesday, the finch, and today we continued with hominin adaptations.
Moving forward, we’ll consider primate evolution and then hominin evolution from the fossil record. Fun stuff!