I. Primates A. Humans, monkeys, and apes belong to the group of mammals known as primates. 1. All primates have opposable thumbs, binocular vision, and flexible shoulders that allow the arms to rotates. 2. These shared characteristics indicate evolution from common ancestors. B. Opposable thumb allows us to grasp and hold things with our hands. 1. Tree dwelling primates can hold on to branches. C. Binocular vision permits judgment of depth or distance with eyes.
I. Primates D. Primates are divided into two major groups. 1. Strepsirhines: includes lemurs, and tarsiers (See figure ). 2. Haplorhines: includes monkeys, apes, and humans.
I. Primates E. Hominids 1. About 4 to 6 million years ago (mya) Humanlike primates appeared that were different from the other primates. 2. Hominids ate both meat and plants, walked upright on two legs. a. Shared some of these characteristics with gorillas, orangutans, and chimpanzees, but a larger brain separated them from apes!!!!
I. Primates F. African Origins 1. Early 1920’s a fossil skull was discovered in a quarry in South Africa. a. Skull had small space for brain but humanlike jaw and teeth. 2. Fossil named Australopithecus, was one of the oldest hominids discovered. 3. An almost complete skeleton of Australopithecus was found in N. Africa in 1974, called Lucy. a. Had similar brain, but was thought to have walked upright. b. This fossil indicates that modern hominids might have evolved from similar ancestors.
I. Primates G. Early Humans 1. 1960’s the hominid fossil that was found in Africa was more like present day humans than Australopithecus. a. Hominid fossil was named Homo habilis , meaning “handy man” because simple tools were found near him. b. Homo habilis is estimated to be 1.5 to 2 million years old. c. Homo habilis gave rise to the Homo erectus, about 1.6 million years ago. i. Homo erectus had a large brain than Homo habilis, and traveled from Africa to Southeast Asia, China, and possibly Europe. d. Homo habilis and Homo erectus are thought to be ancestors of humans. **Because they had larger brains and more human like features than Australopithecus**
II. Humans A. Homo sapiens 1. Evolved about 400,000 years ago; according to fossil records. 2. Neanderthals and Cro-Magnon probably lived at the same time in parts of Africa and Europe about 125,000 years ago.
II. Humans B. Neanderthals 1. Characteristics of Neanderthals a. Short, heavy bodies with thick bones, small chins, and heavy browridges were physical characteristics of Neanderthals. b. Families lived in caves c. Used well made stone tools to hunt large animals. 2. Disappeared from fossil record about 30,000 years ago. 3. Probably not direct ancestors of modern humans, but represent a side of human evolution.
II. Humans C. Cro-Magnon Humans 1. Fossils have been found in Europe, Asia, and Australia; date from 10,000 to about 40,000 years in age. 2. Physical appearance was almost the same as that of modern humans. 3. Characteristcs a. Lived in caves, made stone carvings, buried their dead 4. The oldest recorded art has been found on the walls in caves in France. a. Painted bison, horses, and people carrying spears. 5. Cro-Magnons are thought to be direct ancestors of early humans, Homo sapiens, which means wise humans. 6. Evidence indicates that modern humans, Homo sapien sapiens, evolved from homo sapiens.