Transcript PPT - Standish

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.
Carolus Linnaeus – developed a system of
classification know as “taxonomy” – the modern
system for classifying plants & animals that
reflect natural relationships (ie. Mammals,
Reptiles)
 Joseph Banks – sailed with James Cook and
collected previously unknown plants & animals;
used Linnaeus’ taxonomy for classification
 Gregor Mendel – a botanist, considered the
founder of modern genetics, concluded that
characteristics are passed down from generation
to generation
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 Jean
Baptiste de Lamarck – a zoologist, developed
a number of theories on how animals species
develop over time; from simple forms into more
complex (ie. Giraffes and long necks for food)
 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”
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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).
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“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 treedwelling 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 1.5 – 4 million
years ago
Homo
Neanderthalis
35,000 – 85,000
years ago
Homo Habilis
1.75 million
years ago
Cro-Magnon
10,000- 35,000
years ago
Homo Erectus
300,000 -1.5
million years ago
Homo Sapiens
10,000 - present
years ago (but
not always in
class)
 Australopithecus
- A genus of the family
Hominoidea characterized by small-brained
hominids with mixed fruit/vegetable diet.
 Homo
- A genus of the family Hominoidea
characterized by large-brained hominids with
an omnivorous diet
 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
One of the earliest of modern
man's ancestors, Australopithecus
afarensis lived between 4 million
and 3.2 million years ago in
eastern Africa.
Australopithecus africanus lived
between 3 and 2.3 million years
ago mostly in South Africa
(below) A single footprint of
Australopithecus afarensis
(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
 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
 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
 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
 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
 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
STONE HENGE It was used as a religious or ceremonial center by the prehistoric inhabitants of the region.
 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 bandedflint hand ax. (Centre) Acheulean hand tool. (Bottom, left to right)
Mousterian bifacial hand ax, scraper, and bifacial point.
Dagger Carvings –
Stonehenge
Horse in world's oldest painted
prehistoric cave, 15,000-10,000
BC Lascaux, France