august 31, 2007 – april 20, 2008 turning points in evolution

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August 31, 2007 – April 20, 2008

Turning Points in Evolution Leading to the Development of Culture

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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.

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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.

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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.

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Lucy is one of many individuals from the past who can help us to

understand the steps on the path to becoming human.

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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.

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

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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

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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

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

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How do we learn about how humans lived for

the past 6 million years?

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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?

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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

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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.

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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.

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PDYN aids brain chemicals which underlie perception, behavior and memory, all crucial for the

improvement of relationships with others needed for culture to develop.

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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.

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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.

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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.

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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.

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Paleo-neurology backs up the prey advantage by revealing that the

hormone oxytocin promotes trust during human interactions.

Cooperative behavior allows peopleto 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.

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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.

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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.

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"Toumai” Sahelanthropus tchadensis,

is between 6 and 7 million years old.

Early Homo sapiens appeared about 200,000

years ago

Australopithecus africanus lived

between 3.3 and 2.4 million

years ago.

Below left, Toumai is currently one of the oldest hominid skulls found. It is quite small compared to

the first Homo sapiens.

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“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)

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As culture became more advantageous

for survival, natural selection

favored those whose genes improved ourcapacity to

pass on information from one generation

to the next.

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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.

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Tool making shows unprecedented power of

anticipation with insight into properties of stone.

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1.5 million years ago, the Acheulean hand ax

appeared which required following a pattern

in order to create.

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Around 400,000 years ago shelters began tobe more common

–such as that at Terra Amata,

near Nice, Italy.

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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.

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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 classificationKingdom:Animalia

Phylum:ChordataClass:MammaliaOrder:PrimatesFamily:HominidaeGenus:HomoSpecies:H. sapiensSubspecies:H. s. sapiensTrinomial nameHomo sapiens sapiensLinnaeus, 1758

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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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.

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Domestication of dogs began as people discovered

that wolves kept the camp site clean.

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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.

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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.

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The need to sustain family and group relationships in order to maintain survival created the advancements in human

conditions throughout time.

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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

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

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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.

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Our legacy from the past is not about skills in warfare and aggression. It is peace and cooperation.

Social cooperation leads to advancement of society.

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The goal is to discover who we are and how we got that way. The fascination with our origins gives us a perspective on ourselves, our place in nature and

how we view our future.

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"We must learn to be good neighbors, and I'm optimistic. 

People cannot be foolish forever.“

I.A. Rehman, A Pakistani human-rights activist, on the relations between India and

Pakistan as his country celebrates its 60th year of

independence.Time Magazine, August 27, 2007