August 31, 2007 – April 20, 2008 Turning Points in Evolution

1. August 31, 2007 – April 20, 2008 Turning Points in Evolution Leading to the Development of Culture

2. Who was Lucy? Lucy was one of mankind’s earliest ancestors. She lived in Africa 3.2 million years ago and was a member of the zoological family called “hominidae”. Hominids walk on 2 legs. She was a member of the species Australopithecus afarensis, which is now extinct.

3. 40% of Lucy’s bones were found in Ethiopia by American anthropologist Donald Johanson in 1974. This fossil is part of the Lucy’s Legacy exhibition.

4. Although Lucy is no longer considered the oldest hominid fossil, she continues to be the touchstone by which all other finds are judged. Compare Lucy, top left, to other hominids below.

5. Lucy is one of many individuals from the past who can help us to understand the steps on the path to becoming human.

6. What makes us human? We have a unique consciousness which creates a desire to understand ourselves and the world around us. Awareness of what is basic to all of us will help us to respect each other and work together for a brighter future.

7. Through the blending of science and history we can better understand our progress through the ages.

8. Factors in understanding the evolution of mankind • Environmental changes which caused hominids to evolve • How the study of genetics, DNA, and genomes aids our understanding of evolution • Milestones of development leading to our unique human capabilities • How we can use this knowledge to improve our future living conditions

9. What are the differences between humans and other animals? Humans possess the following unique traits: • walk on 2 legs • larger brain size • smaller jawbone • use tools to make tools • a sense of morality and virtuousness • the ability to reason and invent • symbolic thought exhibited through the use of language and artistic expression • organized social groups – passing on their cultures

10. Culture is the knowledge shared by a group of people. It involves the communicating, or passing on of information from one generation to another.

11. How do we learn about how humans lived for the past 6 million years?

12. We used to only learn about our ancestors from “stones and bones,” -tools and fossils. We have now developed a language to understand new storytellers - DNA and chemicals in the brain. But what can paleo-neurology tell us about culture?

13. Because DNA changes at a constant rate, we can determine how long ago mutations occurred. By studying this “molecular clock,” we can see bursts of changes which coincide with leaps in culture along the path to the development of modern consciousness. Genome

14. The first step occurred around 6-7 million years ago. There was a time of global cooling which caused many areas of East Africa to become drier. The heavily wooded areas changed to grasslands. Large apes living in dense forests had to adapt to more open environments with fewer trees. Some adapted by standing and walking on 2 legs.

15. By studying the molecular clock, we have found that PDYN (prodynorphin) is a brain regulatory gene which began changing 7 million years ago, soon after the first hominids appeared.

16. PDYN aids brain chemicals which underlie perception, behavior and memory, all crucial for the improvement of relationships with others needed for culture to develop.

17. Another example is a gene called HAR1, for “human accelerated region”. HAR1 is plentiful in cells of neurons in the human cortex. It helps to develop the elaborate folds of our complex brains. It is present in animals from chickens to chimps to humans.

18. From 310 mya to 5 mya, it changed only 2 of its 18 letters in its genetic code. Since 5 mya, 18 letters have changed. This dramatic rate of change tells us that this keeps conferring advantages on those species who carry it.

19. Lucy’s species thrived for over 3 million years. This leads us to wonder – what does it take for one species to survive? For decades scientists thought that hunting prowess and the ability to destroy predators was the key to success, but DNA studies now show it is the prey, not the predator that evolves the characteristics needed to survive.

20. Prey developed wit and social skills. Being hunted led our ancestors to cooperate and live in cohesive groups for protection. That, more than aggression and warfare, is our legacy.

21. Paleo-neurology backs up the prey advantage by revealing that the hormone oxytocin promotes trust during human interactions. Cooperative behavior allows people to live together supporting each other. Changes in oxytocin in the past 7 million years may contribute to the human ability to create enduring bonds between men and women.

23. Although behavior does not fossilize, footprints have been found in Laetoli, Tanzania, from the same species as Lucy. They show large and small feet walking side by side.

24. The shape of the brain also tells us which species had higher thinking skills than others. The long surviving species, Australopithecus africanus, had a large frontal lobe where higher level thinking such as decision making, taking initiative, and advance planning takes place.

25. Below left, Toumai is currently one of the oldest hominid skulls found. It is quite small compared to the first Homo sapiens. Early Homo sapiens appeared about 200,000 years ago Australopithecus africanus lived between 3.3 and 2.4 million years ago. "Toumai” Sahelanthropus tchadensis, is between 6 and 7 million years old.

26. “Biological change, or evolution, is facilitated by the transmission of genetic information from one generation to a succeeding one by the configuration of DNA in genes. Cultural evolution is the passing on of information by behavioral means and involves the processes of teaching and learning.” (From Lucy to Language by Donald Johanson, page 21)

27. As culture became more advantageous for survival, natural selection favored those whose genes improved our capacity to pass on information from one generation to the next.

28. One of the major steps along the path to modern abilities was the invention of tools. 2.6 million years ago, Homo habilis was the first hominid to appear with a brain larger than a chimps’. He was the first toolmaker of stone tools. Around this same time the next Ice Age began.

29. Tool making shows unprecedented power of anticipation with insight into properties of stone.

30. 1.5 million years ago, the Acheulean hand ax appeared which required following a pattern in order to create.

31. Around 400,000 years ago shelters began to be more common – such as that at Terra Amata, near Nice, Italy.

32. 200,000 years ago Mousterian stone tools were beautifully made with many varieties and consistent patterns. Some were used to work wood and scrape hides.

33. Homo sapiens emerged in Africa about 200,000 years ago. They were the first species to develop our modern human sensibilities such as foresight, planning, intuition, and awareness of time and space. Scientific classification Kingdom:AnimaliaPhylum:ChordataClass:MammaliaOrder:PrimatesFamily:HominidaeGenus:HomoSpecies:H. sapiensSubspecies:H. s. sapiensTrinomial nameHomo sapiens sapiensLinnaeus, 1758

34. Homo sapiens began wandering out of Africa about 80,000 years ago. It is estimated about 4,000 people ventured out of Africa and created the diverse populations we know today.

35. In order for these Homo sapiens to travel long distances, it is believed that they formed cooperative social alliances for which they must have developed a way to communicate instruction.

36. We have evidence that language and thus symbolic thought emerged about 50,000 years ago. The capacity had to be developing long before it appeared.

37. Scientists have searched the human genome for genes that emerged at the same time as we believe language did. They found one called FOXP2. It developed between 200,000 and 50,000 years ago. During the same time period, hunting skills emerged, probably along with cooperation.

38. The development of symbolism is shown in early artistic representations. This horse was found in Vogelherd Cave in southwestern Germany. It is 40,000 years old.

39. One of the most amazing works of art in all of time is in this cave near Lascaux, France. It was created 17,000 years ago.

40. Homo erectus made use of fire up to 1.5 million years ago, but there is no evidence that man actually created fires until about 15,000 years ago. Being able to control fire brought about a huge leap in socialization skills.

41. The hearth became a place where people gathered for light, warmth, protection, and a social focus. The cooking of food renders it more digestible and kills parasites, so it may have raised the life span of its users.

42. Throughout most of time, people have survived through hunting and gathering, foraging and collecting. Foragers roam around making use of any resource they come upon.

43. Collectors planned the use of resources whose whereabouts were known and carefully monitored. This required pre-thought and planning. Collectors had a central base from which they went out to specific sites for certain resources.

44. Domestication of dogs began as people discovered that wolves kept the camp site clean.

45. Closely following the ending of the last Ice Age around 10,000 years ago, some cultures adapted by taking the first steps toward agriculture. Slow incremental changes have led to the domestication of plants and animals, setting thestage of our own world.

46. A gene believed to aid in brain growth, ASPM appeared about 5,800 years ago, just as people began establishing the first cities in the Near East.The city below is Bam, Iran.

47. The need to sustain family and group relationships in order to maintain survival created the advancements in human conditions throughout time.

48. What are the steps towards humanity that we have observed? • Walking upright • Closer personal bonds • Increase in brain size • Living in cooperative, cohesive groups • Increased creative skills • Tool making • Mastery of fire • Building shelter

49. Creation of a home base • Dispersion from Africa • Group alliances • Symbolic thought • Spoken language • Art • Agriculture • Domestication of animals • Living in cities

50. What do we see recurring that we need to pass on to our students? • All mankind comes from the same roots and have gone through the same growth processes. • The advancement of mankind has taken place due to peaceful relationships between people. Without the cooperation to form groups and work together, we would not have survived.