HUMAN EVOLUTION - the process by which

human beings developed on Earth

from now-extinct primates.

Evolution refers to change over time, or transformation over time.

Evolution assumes that all natural forms arose from their ancestors and adapted over time to their environments.

There are numerous ways in which evolution occurs, the most noted are Natural Selection and Adaptation.

Charles Darwin (1809 - 1882) – the one everyone knows for the theory of evolution; gradual change over generations and survival of the fittest (natural selection) - when his works were first published they created a huge controversy “is it from your mother’s side or your father’s side that you are descended from apes”

Darwin's Theory of Evolution - all life is related and has descended from a common ancestor: the birds and the bananas, the fishes and the flowers -- all related.

In a nutshell, as random genetic mutations occur within an organism's genetic code, the beneficial mutations are preserved because they aid survival -- a process known as "natural selection." These beneficial mutations are passed on to the next generation. Over time, beneficial mutations accumulate and the result is an entirely different organism (not just a variation of the original, but an entirely different creature).

“Natural selection acts only by taking advantage of slight successive variations; she can never take a great and sudden leap, but must advance by short and sure, though slow steps.“ – Charles Darwin

Natural selection acts to preserve and accumulate minor advantageous genetic mutations.

Suppose a member of a species developed a functional advantage (it grew wings and learned to fly). Its offspring would inherit that advantage and pass it on to their offspring. The inferior (disadvantaged) members of the same species would gradually die out, leaving only the superior (advantaged) members of the species.

Natural selection is the preservation of a functional advantage that enables a species to compete better in the wild. Natural selection is the naturalistic equivalent to domestic breeding. Over the centuries, human breeders have produced dramatic changes in domestic animal populations by selecting individuals to breed. Breeders eliminate undesirable traits gradually over time. Similarly, natural selection eliminates inferior species gradually over time.

Fossil - The mineralized bone of an extinct animal. The remains of past life-forms.

Primate - Large-brained, mostly tree-dwelling mammals with three-dimensional color vision and grasping hands. Humans are primates.

Hominid - Modern human beings and our ancestors, generally defined as the primates who habitually walk erect. Technically, the members of the family Hominoidea.

Australopithecus afarensis

Australopithecus africanus

Australopithecus robustus

Australopithecus boisei

1.5 – 4 million years ago First fossils found in 1924, a young child Small brain capacity 450 - 500 cm3

Large brows and flat forehead Mary Leakey discovered a complete skull

1959 in Tanzania Donald Johanson in 1974 discovered the

remains of the most complete specimen ever found – known as “Lucy”

They may have used primitive tools, but little evidence

Our most ancient ancestor is Australopithecus afarensis. They lived roughly 4 - 2.75 million years ago. " Lucy" is the skeleton remains of an Australopithecus afarensis which has made us aware of this species.

Males and females show a considerable difference in size, varying from 1 - 1.7 m in height and from 25 - 50 kg in weight. This bipedal ancestor had a brain capacity that fluctuated from 380 - 450 cc.

(above) A single footprint of Australopithecus afarensis (top), left some 3.5 million years ago at Laetoli, Tanzania,

shows a striking similarity to a single footprint of a habitually barefoot modern

human being from Peru

(below) A single footprint of Australopithecus afarensis

Australopithecus africanus inhabited the earth roughly 3 - 1.6 million years ago.

The characteristic difference between the Ausrtalopithicus afarenis and africanus is the height and brain capacity.

The height of the africanus is 1.4 m and the brain capacity is approximately 400 - 600 cc. Smaller incisor teeth and a slightly flatter face are also noted.

The afarensis has a height of 1.2 m and a cranial capacity of 380 - 450 cc.

Sticks, and stones were most likely used to gather food by the Australopithecus africanus.

Australopithecus africanus lived between 3 and 2.3 million years ago mostly in South Africa

One of the earliest of modern man's ancestors, Australopithecus afarensis lived between 4 million and 3.2 million years ago in eastern Africa.

The Australopithecus robustus dates from approximately 2.3 - 1.3 million years ago.

The difference between Ausrtalopithecus robustus and both afarensis and africanus becomes apparent in the comparison of their structure.

Australopithecus robustus had an average height of 1.5 m and weighed 45 kg on average (much larger then both Australopithecus afarenis and africanus). As well as a larger bone structure, the Australopithecus robustus also had a larger cranium capacity ranging from 500 - 600 cc, housed by an large skull.

As is characteristic of most of the Australopithecus, robustus had a flat face. It's muscular jaw and flat, almost molar-like teeth seemed to imply that the Australopithecus was likely a vegetarian

Australopithecus boisei inhabited eastern Africa approximately 2.5 - 1.2 million years ago.

The Australopithecus boisei's skull is similar to that of the Australopithecus robustus, in which they both have a distinct ridge on the top of their skulls.

Australopithecus boisei has a relatively level face and possesses an extremely large jaw which coincides with their wide teeth.

Homo Habilis

Homo Erectus

Neanderthals

Cro-Magnons

Homo Sapiens

1.75 million years ago The handy human being first discovered by

Louis Leakey in 1964 in Tanzania Had a larger brain Australopithecus about

capacity 750 - 1225 cm3 Had large, sharp canine teeth and smaller rear

teeth than Australopithecus An "apelike" (long arms and a small body) body

structure was characteristic of the Homo habilis. It probably used tools for skinning animals and

powerful arms suggest some time spend living in trees

300,000 -1.5 million years ago Eugene Dubois discovered homo erectus on

the island of Java At first he thought it was an “upright ape” but

later changed because of human similarities Remains have been found in China

(called Peking), Tanzania and Algeria Fair sized brain about capacity 750 - 1225 cm3 This species learned to use fire for warmth,

how to co-operate with others to hunt animals and how to design stone tools such as axes

The first species to migrate from Africa during the Pleistocene glacial period was Homo erectus.

They inhabited the regions of southeastern and eastern Asia until approximately 300 000 years ago.

Europe, India, China and Indonesia have all yielded evidence of Homo erectus.

"Turkana Boy" was an African discovery, which shows that Homo erectus had a similar body size to humans. The period that this boy lived in was 1.6 million years ago. Homo erectus, according to some studies, made use of fire and occupied caves.

35,000 – 85,000 years ago Discovered accidentally by quarry workers in

Germany 1856 Thomas Huxley used the discovery to support

Charles Darwin’s Theories Neanderthalis has a similar brain to ours a

capacity 1400 - 1600 cm3 It may have been possible for it communicate

through speech Practiced many social behaviours such as burying

its dead in graves Produced a wide variety of tools such as knifes,

scrapers and chisels

Made clothes from animal skins

First humans to bury their dead

Lived in caves and tents

10,000- 35,000 years ago Again by accident in 1868 in France by

road workers The site not only had fossils but the

artifacts of a community, including tools and shelters

Later remains were discovered in Italy, France and Czech Rep.

Highly developed culture, decorated hand tools, ornaments and cave paintings

Very good hunters, worked in teams

Approximately 35 000 years ago, Cro-Magnons, moved into the Neanderthal region of what is today known as France.

Within the time from 35 000 - 10 000 years ago the evolution of art and technological innovations becomes apparent.

Cro-Magnons used paints composed from manganese and iron oxides to paint the walls and ceilings of their caves through-out what is today called France and Spain.

Many of these beautiful paintings have been preserved and can still be seen.

During the seasonal migration of herds, the Cro-Magnons used cunning hunting skills and tools to kill their prey.

They managed to develop extremely advanced tools for hunting (possibly even a bow and arrow).

The Cro-Magnon dwelled primarily in caves or rock shelters in groups.

10,000 years ago - present Homo sapiens named “wise humankind” – yet

to be proven Large brain capacity 1450-1600 cm3 , power of

communication through speech Developed sophisticated tools of stone and

iron Also advanced cave painting to new levels Stonehenge a prehistoric monument in southern

England originates from this period – sense of religion & supernatural

Species has continued to change from nomadic to settlement/agricultural life around 5000 years ago

Bipedalism (moving/walking on 2 legs) Hand Functions Cranial Capacity (size of skull –

determines brain size) Tool Design Tooth Size Communication - Speech, Language, Art

Several differences allow the human being to walk erect on two legs with a striding gait rather than move in a knuckle-walking fashion like the gorilla – one example includes: in the legs the femurs (thighbones) are relatively long and are set farther apart at the hips than they are at the knees.

The increase in hominin cranial capacity over time.

Stone tools of the Acheulean industry, used by Homo erectus and early modern humans, and of the Mousterian industry, used by Neanderthals. (Top, left to right) Mid-Acheulean bifacial hand ax and Acheulean banded-flint hand ax. (Centre) Acheulean hand tool. (Bottom, left to right) Mousterian bifacial hand ax, scraper, and bifacial point.

Horse in world's oldest painted prehistoric cave, 15,000-10,000 BC Lascaux, France

Dagger Carvings – Stonehenge

http://www.pbs.org/wnet/humanspark/episodes/program-two-so-human-so-chimp/video-full-episode/407/

http://www.pbs.org/wnet/humanspark/episodes/program-one-becoming-us/video-full-episode/395/

http://video.pbs.org/video/1312522241/