GEOL 105L Lecture Notes - Lecture 12: Human Evolution, Hominidae, Herbivore
23 Apr 2020
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Document Summary
Hominid refers to members of the family of humans. There are at least 19 species of hominids. The oldest known hominid lived between 6 and 7 million years ago. Separation between apes and human lines (dna evidence) Great apes and hominids branched from a common ancestor between 7 million and 8 million years ago. Found in hominids with primarily a vegetarian diet. Place for attachment of large jaw muscles required. Herbivores had huge brow ridges and large jaws for chewing and grinding tough vegetation. Omnivores lose the brow ridge and the jaws are smaller as less chewing strength is needed. Increasing brain capacity, especially the regions associated with complex thought, requires a larger cranium and forehead. Differences in skulls reflect changes in diet. Sagittal crests atop the skull for attachment of powerful chewing muscles. Huge, thickly enameled molar teeth for grinding tough vegetation. Transition of african forests to savannah and open forest possibly led to the development of bipedalism.
