Evolution of man

Compete information on how humans evolved

1. Australopithecus Homo erectus Homo sapien EVOLUTION OF MAN

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 Neandertha l 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.

9. CLASSIFICATIONS PHYLUM :CHORDATA CLASS :MAMMALIA ORDER :PRIMATES SUB ORDER :ANTHROPOIDEA GENU :HOMO SPECIES :SAPIENS

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. 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.

13. 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.    

14. 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 6 th and 8 th 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%  

15. GEN OMIC 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.

16. GEOLOGICAL TIME SCALE

17. PRE HUMAN ANCESTORS

18. 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

19. AGEGYPTOPITHECUS FOSSILS FOUND IN CAIRO. FOSSIL APE. SIMILAR TO PROPLIOPITHECUS. LIVED IN OLIGOCENE PERIOD

20. 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.

21. 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

22. 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

23. 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

24. 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

25. 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

26. 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

27. RHODESIAN MAN PRIMITIVE MAN. FOUND IN RHODESIA. LIVED IN LATE PLIOCENE PERIOD. RECEDING FOREHEAD AND HEAVY BROWS. CRANIAL CAPACITY 1300CC

28. 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.

29. HOMO SAPIEND SAPIENS(MODERN MAN) EVOLVED FROM CRO- MAGNON APPEAR FROM HOLOCENE EPOCH NEAR MEDITERRANEAN SEAS CRANIAL CAPACITY 1450 cc ADVANCED IN FORMING TECHNIQUES DOMESTICATE ANIMALS ESTABLISHMENT OF TOWN PRESENCE OF 4 CURVES IN VERTEBRAL COLUMN COURSE OF CULTURAL EVOLUTION HAS BEEN DIVIDED INTO PALEAOLITHIC, MESOLITHIC, NEOLITHIC, BRONZE AGE AND THE PRESENT IRON AGE.

30. 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 5 th digit in the feet will be lost. This future race of man is named as Homo futuris .

31. SUMMARY

32. THANK U