Lecture 2-1

1. Lecture 2-1 The Beginnings of Human Culture

2. Lecture Outline • When, Where, and How Did the Genus Homo Develop? • When Did Reorganization and Expansion of the Human Brain Begin? • Why Is the Relationship Between Biological Change and Cultural Change in Early Homo?

3. Development of Human Culture • Some populations of early hominines began making stone tools to butcher animals for their meat. • The earliest stone tools and evidence of significant meat eating date to about 2.6 m.y.a.

4. Reorganization And Expansion Of The Human Brain • Began at least 1.5 million years after the development of bipedal locomotion. • Began in conjunction with scavenging and the making of stone tools. • Marks the appearance of the genus Homo, an evolutionary offshoot of Australopithecus.

5. Reorganization And Expansion Of The Human Brain • Australopithecus relied on a vegetarian diet while developing a massive chewing apparatus. • Homo ate more meat and became brainier.

6. Early Representatives of the Genus Homo • Since 1960 a number of fossils have been found in East Africa, and in South Africa, which have been attributed to Homo habilis. • From the neck down, the skeleton of Homohabilis differs little from Australopithecus. • Skull shows a significant increase in brain size and some reorganization of its structure.

7. Hand bones

8. Comparison of Partial Foot Skelton • Homo habilis (center) compared with a chimpanzee (left) and modern human (right).

9. Homo habilis and Other Early Hominins

10. Tool Use • Lower Paleolithic artifacts from Olduvai Gorge, Lake Turkana, and sites in Ethiopia required skill and knowledge for their manufacture. • The oldest Lower Paleolithic tools found at Olduvai are in the Oldowan tool tradition. • Oldowan choppers and flakes made the regular addition of meat to the diet possible.

11. Brain Structure and Tool Use • Tool making favored the development of a more complex brain: • Requires a vision of the tool to be made. • Ability to recognize the kind of stone that can be worked. • Requires steps to transform the raw material into a useful tool.

12. Sex, Gender and the Behavior of Early Homo • Males supplied much of the meat, while females gathered other foods. • Females shared a portion of what they gathered in exchange for meat. • Sharing required planning and problem solving.

13. Tools, Food, and Brain Expansion • Increased consumption of meat, beginning about 2.5 m.y.a. made new demands on coordination and behavior. • Procuring meat depended on the ability to outthink more predators and scavengers. • Eaters of high-protein foods do not have to eat as often as vegetarians, leaving time to explore and experiment with their environment.

14. Language Origins • There is a growing consensus that all great apes share an ability to develop language skills to the level of a 2- to 3-year-old human. • In the wild apes display language skills through gestures.

15. Language Origins • Regions of the human brain that control language lie adjacent to regions involved in precise hand control. • Oldowan toolmakers, like modern humans, were overwhelmingly right-handed. • In making tools, they gripped the core in the left hand, striking flakes off with the right.

16. Language Origins • Handedness is associated with lateralization of brain functions and lateralization is associated with language. • Tool making appears to have been associated with changes in the brain necessary for language development.

17. Brain Lateralization Lateralization is the idea that the two halves of the brain's cerebral cortex -- left and right -- execute different functions. The lateralization theory -- developed by Nobel-prize-winners Roger Sperry and Robert Ornstein -- helps us to understand our behavior, our personality, our creativity, and our ability to use the proper mode of thinking when performing particular tasks. (The cerebral cortex is a part of the brain that exists only in humans and higher mammals, to manage our sophisticated intellect.)

18. Is your Brain Cross-Lateralized? The human brain has two hemispheres, each differing from the other. This is called hemispheric lateralization. Basically, people are either right- or left-handed. When it comes to other traits, in addition to handedness, people are right- or left-dominant. How is your own brain generally lateralized? Do you have any cross-lateralizations? Take this brief quiz to discover your degree of cross-lateralization, and what it may mean.

19. 1.Are you primarily left- or right-handed? leftright • 2.When kicking a football, which foot do you use to kick it? leftright • 3.Cross your arms comfortably. Which hand is on top? leftright

20. 4.Keep both your eyes open while you extend your hand and point to an object twenty feet away. Now close your left eye. Is your finger still pointing directly to the object, or did a shift occur? - it's still pointing directly to object - no, a shift occurred

21. 5.Clasp your hands comfortably. Is your right thumb on top? yesno • 6.When writing in longhand, which hand do you use to hold the pen? leftright • 7.When tossing a ball, which hand do you use? leftright

22. 8.When chewing gum, which side do you usually chew on? leftright • 9.When talking on the phone, which ear do you put against the receiver? leftright

23. For results go to: http://mindbluff.com/phplater.htm