This document provides an overview of human evolution, beginning with early primate ancestors such as Propliopithecus that lived 50-25 million years ago. It describes several pre-human ancestors in chronological order, including Australopithecus, Homo habilis, Homo erectus, Homo heidelbergensis, Neanderthals, and Cro-Magnon. It discusses evidence for human evolution from molecular biology and genetics. The document also covers theories of human origins, morphological changes during humanization, and timelines of evolutionary periods.
2. CONTENTS
Introduction
History of human evolution
Major sites of human fossils
Places of origin of man
Time of origin of man
Monophyletic or polyphyletic origin of man
Punctuated equilibrium in human evolution
Primate heritage
Genomic changes in human evolution
Geological time scale
Pre-human ancestors
Future of man
3. INTRODUCTION
•Human evolution is the lengthy process of change by
which people originated from apelike ancestors.
Scientific evidence shows that the physical and
behavioral traits shared by all people originated
from apelike ancestors and evolved over a period of
approximately six million years.
•Humans are primates. Physical and genetic
similarities show that the modern human species,
Homo sapiens, has a very close relationship to
another group of primate species, the apes. Humans
and the great apes (large apes) of Africa --
chimpanzees (including bonobos, or so-called
“pygmy chimpanzees”) and gorillas -- share a
common ancestor that lived between 8 and 6 million
years ago..
4. HISTORY OF HUMAN EVOLUTION
T.H. HUXLEY (1863) made first attempt to man’s origin in
his book ‘Man’s Place In Nature’ and visualized apes the
closest human relatives. Later in 1871, Charles Darwin
advocated his idea about man’s ancestry in his book ‘The
Descent With Man’ and propounded origin of man from
apes
First fossils of human ancestors were described by
Eugene Dobois in 1880’s.This includes skull cap, lower
law jaw fragments and Thigh bones from East Indies.
Most pre human fossils were discovered and studied
from 1920 onwards.
The main contributors for the study of human evolution
were Raymond Dart (1920s), Davidson Black (1934), L.S.B
Leakey and Mary Leakey and their son Richard.
5. MAJOR SITES OF HUMAN FOSSILS
HUMANS AND PREHUMAN FOSSILS HAVE
BEEN OBTAINED FROM Africa, India,
China, Algeria and Europe. In South
Africa, fossils of Australopithacus,
Paranthropus ,Homo erectus and Neanderthal
man were Tanzania, Java, Zambia and
Kenya respectively. East Africa,
Israel, Iraq and Lebanon were rich in
human fossil deposits of Neanderthal,
Heidelberg and Cro-Magnon man.
6. PLACE AND TIME OF ORIGIN OF
MAN
The fossils of pre-human and ancestral human forms
have been obtain from widely diverse regions of Africa,
Asia and Europe which indicate that man’s centre of
origin was probably in Asia and Africa. Most precisely
in Central Asia
Primates are presumed to have started evolving in
Eocene of Tertiary Period between 75 and 60 million
years ago . They were small lemur like animals . They
were primarily arboreal with a long tail and small face .
In late Oligocene, about 25 to 30 million years ago, when
these evergreen forests were replaced by drier
Savannah Grasslands, some tree dwelling primates
returned back to the ground and became ancestors of
apes and man . Thus evolution of man and apes started
together about 25 to 30 million years ago. Humanization
separated from other apes about 6 million years ago in
Pliocene ( in Africa ) .
7. MONOPHYLETIC ORIGIN OF MAN
There are two main views about the
origin of modern man ( Homo sapiens
sapiens ). These are :
Single origin Hypothesis : According
to these hypothesis modern man has
evolved in one locality ( In Africa )
about two millions years ago . From
here ancestors migrated to all
others continents Old World and
replaced all others extant
populations of Homo sapiens .
Multiregional Hypothesis : According
to this model, human evolution has
occurred almost simultaneously in
different unconnected localities in
the Old World . Several populations
in different regions of the Old World
evolved independently to become
Homo sapiens and then further evolved
into modern humans showing parallel
evolutions
8. PUNCTUATED EQUILIBRIUM IN
HUMAN EVOLUTION
According to this theory,
evolutionary changes
occurred in rapid bursts.
These punctuated episodes
were separated from long
periods of stasis in
hominid lineages during
which little or no
morphological change took
place. This is described as
rectangular pattern
instead of tree like
pattern as found in the
evolution of different
groups.
10. COMPELLING CAUSES OF EVOLUTION OF MAN
According to the distinguished anthropologist Sherwood Washburn,
divergence of human and apes from their primate ancestors must
have occurred after the development of brachiation because they
still retained certain brachiating characters such as broad trunk,
flexible arm and strong collar bone. What lead to their return to
ground must be the climatic changes.
The Pliocene Period was characterized by continental evolution
and consequently increased aridity of climate. With this increased
aridity, heat and tempering of tropical condition, the forest
dwindled and shrinked towards the equator. They were replaced by
widely spread Savanna and grassland. Dart presume that the
gradual shrinking of forest and reduction in the number of trees
compelled tree-dwelling forms to get down to the ground. Once on
the ground, they rapidly acquired such adaptation as were
necessary to ensure survival in the new habitat. The adaptation
included :
Prolonged childhood
Retarded maturity of the skull
Increase of the brain and finally
The adaptation to live in open country. These changes framed out
individuals which are called HUMANS.
11. MORPHOLOGICAL SIMILARITIES AND
DIFFERENCES BETWEEN MAN AND APES
Great similarities between ape and man indicates that they
have evolved simultaneously and from some common ancestral
stock for quite some time. After that man’s ancestors assumed
bipedal gait and upright posture, whereas ape’s ancestors still
used their knuckles. Following are the special features of man
which have been acquired during humanization:
Bipedal locomotion
Upright posture
Forelimbs evolved into efficient grasping manipulation and
maneuvering devices for making tools, hurling weapons,
carrying objects.
Opposable thumbs
Large brain and high cranial capacity.
Face became orthognathous, simian shelf absent, chin present
eye brow ridges absent
12.
13. In man dental arch is rounded parabola, canines and
incisors are small, simian gap is absent in the upper jaw
between incisors and canines.
Man is omnivorous now
Intelligence reached highest level
Humans have evolved large forwardly directed eyes with
great power of accommodation and possess binocular and
stereoscopic vision enabling depth perception and distance
estimation
Olfactory lobe is less developed
Birth rate is reduced and polyembryony was lost.
Loss of body hair
Social and cultural organization
All difference between modern apes and man indicates both
might have evolved from some common ancestors
simultaneously but on 2 different path. Apes tool to
brachiation and man returned back to ground habit.
14.
15. EVIDENCES FROM MOLECULAR BIOLOGY IN
SUPPORT OF HOMINID EVOLUTION FROM APES
Advancement in the field of molecular biology has solved the degree of
closeness between different primates and tracing their relationship.
Comparison of amino acids sequences in considerable number of
homologous proteins (such as hemoglobin, cytochrome c, serum albumin)
or cross reactivity of such proteins found in man and ape has clearly
indicated close relationship between man and ape and chimpanzees is the
closest to man.The relationship between two is described in terms of
immunological distance between their homologous proteins and the time of
their divergence. some of similarities are follows:
Structure of hemoglobin: comparison in the sequence of amino acids in the
polypeptide chains of hemoglobin of man, chimpanzee, and monkey shows
that there is absolute no difference in the sequencing of141 amino acid in
each alpha chain and 146 amino acids in each beta chain oh hemoglobin of
man and chimpanzee.There are only 2 differences out of 287 amino acids
between hemoglobin of man and chimpanzee and between that of man and
monkey there are 12 differences.
Molecular structure of other proteins: molecular structure of cytochrome c,
insulin and serum albumin in man and apes exhibits minimum difference.
Humans and chimpanzee’s polypeptide exhibits on an average 99%
similarity.This makes chimpanzee closest living relative of man.
16. Chromosomes: somatic cells of man have 46 (23 pairs)
chromosomes. In apes their number is 48. Man has evolved from an
ancestor having 48 chromosomes by the centromeric fusion of 2
chromosomes.
Chromosomes of man and apes have been studied with special
staining techniques and it has been established that:
Chromosomes of man and apes have similar bending pattern
Some chromosome of man and apes have identical BANDS
Similarities in the bands of 6th and 8th chromosomes indicates that
both apes and man have evolved from common ancestors
Similarities in DNA: in 1971 Bill Hoyer, David, Kohne and others
compared the similarities of DNA between apes and man by DNA-
DNA hybridization method.This indicates the similarity in the
nucleotide sequence between the DNA molecules of the two
species.There exists a difference of 2.5 %between the DNA of
chimpanzee and man. Difference in the DNA of man and monkey is
about 10%
17.
18. GENOMIC CHANGES IN HUMAN
EVOLUTION
Evolution of man from chimpanzee is attributed to gradual
changes in the genome or DNA. Scientists from U.S, Belgium and
France have identified 49 human accelerated regions
(HARs)where significant changes in the nucleotide arrangements
have occurred during 10 million years or so.The most active
HARs identified has HAR1 is found to have 8 out of
116nucleotides changed since the evolutionary separations of
humans from chimps about 6 million years ago.
Most probably the HAR1 region of the genome is associated with
the critical steps in the development of brain. However, it
appears that the evolution of just one region in the genome could
not make all the difference between humans and chimp’s brains.
It is much likely that a series of many small changes have got
added up to produce the result.These changes in brain
development are produced during the key formatives period for
human brain from 7 to 19 weeks of gestation.
22. PROLIOPITHECUS
APE-LIKE PRIMATE.
SHORT ARMS.
LIVED IN OLIGOCENE
PERIOD
ANCESTORS OF MODERN
APES AND MAN.
THEIR DENTAL FORMULA IS 2,
1, 2, 3x2
Their incisor teeth were vertical
rather than direct forward and
molars had 5 cusps each
24. DRYOPITHECUS
• LIVED IN OLIGOCENE PERIOD
OR EARLY MIOCENE PERIOD.
• DESCENDED FROM
PROPLIOPITHECUS.
• HAD ARMS AND LEGS OF
SAME LENGTH,HAS
SEMIERECT POSTURE,
WITHOUT BROWRIGDES
• IT WAS ARBOREAL, KNUCKLE
WALKER, ATE SOFT FRUITS
AND LEAVES.
• COMMON ANCESTORS OF
MAN AND APES.
25. RAMAPITHECUS
PRIOR TO APEMAN
LIVED IN LATE MIOCENE AND
EARLY PLIOCENE PERIOD.
FOSSIL CONTAINS ONLY JAWS AND
DENTITION( V SHAPED .
COLLECTED FROM INDIA AND
AFRICA.
DIRECT ANCESTOR TO MAN.
WALKED ERECT ON ITS HIND FEET
HAD SMALL CANINES AND LOW
CROWNED MOLARS CAPPED WITH
THICK LAYER OF ENAMEL,ATE
HARD NUTS AND SEEDS
26. AUSTRALOPITHECUS
APE-MAN.
LIVED IN PLEISTOCENE PERIOD
CONNECTING LINK BETWEEN MAN
AND APE.
AUSTRALOPITHECUS AFRICANUS IS A
COMMON FOSSIL
ERECT POSTURE WITH 4 FT HEIGHT.
BIPEDAL LOCOMOTION.
BASIN-LIKE PELVIC GIRDLE.
DENTITION LIKE MAN.
HANDS USED FOR NON-LOCOMOTORY
FUNCTIONS.
CRANIAL CAPACITY IS 500 CC
BROW RIGDES PROJECTED OVER
EYES,DID NOT HAVE CHIN
27. HOMO HABILIS
• FIRST TRUE MAN.
• PRIMITIVE MAN.
• LIVED IN PLEISTOCENE PEROID
• ALSO CALLED SKILLFUL MAN OR
TOOL MAKER.
BIPEDAL LOCOMOTION.
TALLER THAN
AUSTRALOPITHECUS.
FLATTENED SKULL.
CANNIBALISTIC.
THEY WERE HUNTERS AND
GATHERERS.
LESS BODY HAIR
BRAIN CAPACITY 700-800 CC
WAS FIRST TO USE TOOLS
28. HOMO ERECTUS
• FORE-RUNNER OF MODERN MAN.
• PRIMITIVE MAN.
• EVOLVED FROM Homo habilis
• 1.5-1.8 METERS HIGH
• HAD PROTRUDING JAWS,
PROJECTING BROW RIDGE
AND SMALL CANINES AND
LARGE MOLAR TEETH
• CRANIUM CAPACITY IS
800-1300 CC
• HE USE FIRE
• ALSO CALLED JAVA MAN.
• LIVED IN JAVA AND PEKING
29. HEIDELBERG MAN
EARLY Homo
sapeins.
LIVED IN LATE
PLEIOSTOCENE PERIOD
FOUND NEAR HEIDELBERG
RIVER.
ANCESTOR TO
NEANDERTHAL MAN.
CRANIAL CAPACITY 1300CC
KNOWN FROM THEIR
MASSIVE LOWER JAW
JAW IS LARGE AND HEAVY
AND LACK A CHIN
30. NEANDERTHAL MAN
• ADVANCED PRIMITIVE MAN.
• FOUND IN NEANDER VALLEY.
SLIGHTLY SHORTER THAN MODERN
MAN.
HAD SLIGHTLY PROGNATHOUS FACE
BRAIN CAPACITY 1300-1600 CC
WALK UPRIGHT , LOW BROWS,
RECEDING JAWS,LARGE TEETH AND
DOMED HEAD
SKILLFUL USE OF TOOLS.
DEVELOPED SPEECH.
CAVE DWELLERS
ADAPTED TO COLD ENVIRONMENT
31. RHODESIAN MAN
PRIMITIVE MAN.
FOUND IN
RHODESIA.
LIVED IN LATE
PLIOCENE PERIOD.
RECEDING
FOREHEAD AND
HEAVY BROWS.
CRANIAL CAPACITY
1300CC
32. CRO-MAGNON MAN
• EXTINCT MODERN MAN.
• LIVED IN OLD STONE AGE.
• LIVED IN CAVES.
• THEY WERE HUNTERS AND ARTISTS.
• CRANIAL CAPACITY 1650 cc
• FACE ORTHOGNATHOUS WITH AN
ARROW, ELEVATED NOSE, BROAD
AND ARCHED FOREHEAD,
MODERATE BROW RIDGES, STRONG
JAWS WITH MAN LIKE DENTITION
AND A WELL DEVELOPED CHIN
• WERE DIRECT ANCESTOR OF LIVING
MODERN MAN.
33. HOMO SAPIEND SAPIENS(MODERN MAN)
EVOLVED FROM CRO- MAGNON
APPEAR FROM HOLOCENE EPOCH
NEAR MEDITERRANEAN SEAS
CRANIAL CAPACITY 1450 cc
ADVANCED IN FORMING
TECHNIQUES
DOMESTICATEANIMALS
ESTABLISHMENTOFTOWN
PRESENCEOF 4 CURVES IN
VERTEBRALCOLUMN
COURSE OF CULTURAL
EVOLUTION HAS BEEN DIVIDED
INTO PALEAOLITHIC, MESOLITHIC,
NEOLITHIC, BRONZEAGEANDTHE
PRESENT IRONAGE.
34. FUTURE OF MAN
Cultural and industrial evolution today has
reached that stage that man can change his
environmental conditions.This has reduced the
impact of biological evolution on human races.
Anthropologist Shapiro, has imagined that
man in future will be tall, slim, and without
body hair.Their skull will be domed shaped and
brain will be large.Their lifespan will increase
and the 5th digit in the feet will be lost.This
future race of man is named as Homo futuris.