PhysicalThe Fossil RecordDating Methods

AnthropologyWhat Makes Us Human?

Differences between Animals and Primates/People

• A thumb that can move freely and independently

• Best developed in humans, but also present in other primates such as apes and monkeys.

• The opposable thumb is what allows humans to manipulate tools, make things and to write.

Abstract Thought

• An idea with no physical form – not concrete.• For example – the idea of justice or fairness is abstract

• Abstract thought allows humans to organize themselves and the world around them.

• Abstract thought allows us to adjust, to speculate, to change and to communicate ideas through words and texts which we write about ideas.

Speech• The ability to communicate vocally using

complex language.• Languages allows us to form, sustain, change

and interact in complex social relationships.• Language is also what we use to socialize our

young.• Humans have created many different

languages with which to communicate with each other.

Dependence • The state of relying on another for help and support.

• Most humans are dependent on their parents for 12 to 21 years.

• Few other creatures remain “children” for so much of their lives.

• The long period of dependence makes human socialization possible.

Socialization

• The process of learning behaviours considered suitable in one’s society and culture.

• Human beings socialize their young primarily through family, extended family, day care and institutions like school.

PRIMATESA primate is any mammal of the order Primates. They

typically have flexible hands and feet with opposable thumbs, good eyesight, and in higher order apes have highly developed brain: this order includes lemurs, lorises,

monkeys, apes, and man

• Give birth to live young• Body hair for warmth• Warm blooded• Stereoscopic color vision, • nails instead of claws on the digits, • tactile pads on the hands, • reduced sense of smell, orbital enclosure and eyes facing

relatively forward,• reduced number of teeth compared to other mammals, • and a relatively large brain to body ratio just to name a few.

How do we learn how we came to be?

FossilsFossils are the evidence of ancient life, usually preserved in layers of sedimentary rocks. Most fossils are the preserved hard parts of animals and plants, such as shells, bones, teeth and wood. They occur in many other forms, including tracks and trails, casts or impressions, in amber, mineralized dung, and leaves in shale.

Earth’s history is divided into several long geological time periods based on the distinctive characteristics of rock as and fossils from those period. It is not exactly known when life arose, but the oldest rocks on earth – formed from 3.8 to 3.5 billion years ago contain fossils of distinctive one-celled organisms.

The Jurassic Period from 206 to 144 million years ago was the height of the age of dinosaurs and the first birds.

The Cenozoic Era from 65 million years ago to the present, is the era when our genus HOMO appeared. It is thought that Homo sapiens, or modern man, developed in the last 250,000 years.

The fossil record is incomplete

Archeologists use Dating Methods Try to learn about what happened in the past.

Stratigraphy – is based on the principle that the oldest layer, or stratum, was deposited first ( it is the deepest) while the newest layer was deposited last )on top). Thus, in archeological sites the evidence is usually deposited in chronological order. The lowest stratum contains the oldest artifacts and /or fossils.

Stratigraphy

Dating cont’d

Radio carbon analysis – is based on the fact that all living organisms absorb radioactive carbon ( known as Carbon 14) which reaches equilibrium with that in the atmosphere, and that this absorption ceases at the time of death. It is possible to measure in the lab the amount of radioactive carbon left in a given organic substance – based on the rate of decay or half-life. The half life of Carbon 14 is 5730 years for one-half of the original Carbon* this method is the same for uranium and potassium-argon analysis