Biology Investigatory Project
INVESTIGATORY PROJECT
Certificate of Authenticity
This is to certify that “K.SANTHOSH KUMAR” a student of class 12th has successfully completed the
research product on the topic “HUMAN EVOLUTION”
Under the guidance of Mrs. KALPANADEVI (PGT BIOLOGY)
This project is absolutely genuine and does not indulge in plagiarism of any kind. This reference taken in
making this project has been declared at the end of this project.
Signature {Teacher In-Charge}
Signature (Internal Examiner) Signature (External Examiner)
ACKNOWLEDGMENT
Having a successful investigatory project is really a great pleasure to us. It helps us improving a certain
project and identifying new discoveries from raw materials which can be seen abundantly in our
surroundings. So, we, the researchers would like to thank to the following persons who help us make this
project successful. First, to our Teacher
Mrs.Kalpana Devi(PGT BIOLOGY) who gave us the wisdom, that lead us to come up on this great idea and
for the guidance that made our project fruitful and helped us in the formulation of the study, and lastly, our
parents who continuously support us in our financial needs in doing our project. Thank You!
CONTENTS
INTRODUCTION
HISTORY OF STUDY
FIRST FOSSILS
GENETIC REVOLUTION
HUMAN DISPERAL
ANATOMICAL CHANGE
EVIDENCES
IMAGINATIVE ROUTE OF HOMASAPEINS
EVOLUTION ANATOMY
BIBILOGRAPHY
Introduction
Human evolution is the evolutionary process leading up to the appearance of modern humans. While it
began with the last common ancestor of all life, the topic usually covers only the evolutionary history of
primates, in particular the genus Homo, and the emergence of Homo sapiens as a distinct species of
hominids (or “great apes”). The study of human evolution involves many scientific disciplines, including
physical anthropology, primatology, archaeology, linguistics, evolutionary psychology, embryology and
genetics. History of study
Before Darwin
The word homo, the name of the biological genus to which humans belong, is Latin for “human”. It was
chosen originally by Carolus Linnaeus in his classification system. The word “human” is from the Latin
humanus, the adjectival form of homo. The Latin “homo” derives from the Indo-European root *dhghem, or
“earth”. Linnaeus and other scientists of his time also considered the great apes to be the closest relatives of
humans based on morphological and anatomical Similarities.
Darwin
The possibility of linking humans with earlier apes by descent became clear only after 1859 with the
publication of Charles Darwin’s On the Origin of Species, in which he argued for the idea of the evolution of
new species from earlier ones. Darwin’s book did not address the question of human evolution, saying only
that “Light will be thrown on the origin of man and
his history”. The first debates about the nature of human evolution arose between Thomas Huxley and
Richard Owen. Huxley argued for human evolution from apes by illustrating many of the similarities and
differences between humans and apes, and did so particularly in his 1863 book Evidence as to Man’s Place
in Nature. However, many of Darwin’s early supporters did not initially agree that the origin of the mental
capacities and the moral sensibilities of humans could be explained by natural selection, though this later
changed. First fossils
A major problem at that time was the lack of fossil intermediaries. Despite the 1891 discovery by Eugène
Dubois of what is now called Homo erectus at Trinil, Java, it was only in the 1920 s when such fossils were
discovered in Africa, that intermediate species began to accumulate. In 1925, Raymond Dart described
Australopithecus africanus. The type specimen was the Taung Child, an Australopithecine infant which was
discovered in a cave. Although the brain was small (410 cm3), its shape was rounded, unlike that of
chimpanzees and gorillas, and more like a modern human brain. Also, the specimen showed short canine
teeth, and the position of the foramen magnum was evidence of bipedal locomotion. All of these traits
convinced Dart that the Taung baby was a bipedal human ancestor, a transitional form between apes and
humans. The genetic revolution
The genetic revolution in studies of human evolution started when Vincent Sarich and Allan Wilson
measured the strength of immunological cross-reactions of blood serum albumin between pairs of creatures,
including humans and African apes (chimpanzees and gorillas). The strength of the reaction could be
expressed numerically as an immunological distance, which was in turn proportional to the number of amino
acid differences between homologous proteins in different species. By constructing a calibration curve of the
ID of species’ pairs with known divergence times in the fossil record, the data could be used as a molecular
clock to estimate the times of divergence of pairs with poorer or unknown fossil records. In their seminal
1967 paper in Science, Sarich and Wilson estimated the divergence time of humans and apes as four to five
million years ago, at a
time when standard interpretations of the fossil record gave this divergence as at least 10 to as much as 30
million years. Subsequent fossil discoveries, notably Lucy, and reinterpretation of older fossil materials,
notably Ramapithecus, showed the younger estimates to be correct and validated the albumin method.
Application of the molecular clock principle revolutionized the study of molecular evolution.
HUMAN DISPERAL
Anthropologists in the 1980s were divided regarding some details of reproductive barriers and migratory
dispersals of theHomo genus. Subsequently, genetics has been used to investigate and resolve these issues.
According to the Sahara pump theory evidence suggests that genus Homo have migrated out of Africa at
least three times (e.g. Homo erectus, Homo hiedelbergensis and Homo sapiens), with other migrations
occurring more recently (e.g. the Afro-asiatic language family into the Middle East). A broad study of
African genetic diversity, headed by Sarah Tishkoff, found the San people had the greatest genetic diversity
among the 113 distinct populations sampled, making them one of 14 “ancestral population clusters”. The
research also located the origin of modern human migration in south-western Africa, near the coastal border
of Namibia and Angola.The fossil evidence was insufficient for Richard Leakey to resolve this debate.
Studies of haplogroups in Y-chromosomal DNA and mitochondrial DNA have largely supported a recent
African origin.Evidence from autosomal DNA also predominantly supports a Recent African origin.
However evidence for archaic admixture in modern humans had been suggested by some studies.
Anatomical changes
Human evolution is characterized by a number of morphological, developmental, physiological,
andbehavioral changes that have taken place since the split between the last common ancestor of humans
and chimpanzees. The most significant of these adaptations are bipedalism, increased brain size, lengthened
ontogeny (gestation and infancy), and decreased sexual dimorphism. The relationship between these changes
is the subject of ongoing debate.Other significant morphological changes included the evolution of a power
and precision grip, a change first occurring in H.
erectus.
Evidence
The evidence on which scientific accounts of human evolution is based comes from many fields of natural
science. The main sources of knowledge about the evolutionary process has traditionally been the fossil
record, but since the development of genetics beginning in the 1970s, DNA analysis has come to occupy a
place of comparable importance. The studies of ontogeny, phylogenyand especially evolutionary
developmental biology of both vertebrates and invertebrates offer considerable insight into the evolution of
all life, including how humans evolved. The specific study of the origin and life of humans is anthropology,
particularly paleoanthropology which focuses on the study of human prehistory.
Evidence from the fossil record
There is little fossil evidence for the divergence of the gorilla, chimpanzee and hominin lineages. The
earliest fossils that have been proposed as members of the hominin lineage are Sahelanthropus tchadensis
dating from 7 million years ago, Orrorin tugenensis dating from 5.7 million years agoand Ardipithecus
kadabba dating to 5.6 million years ago. Each of these have been argued to be a bipedal ancestor of later
hominins but, in each case, the claims have been contested. It is also possible that one or more of these
species are ancestors of another branch of African apes, or that they represent a shared ancestor between
hominins and other apes. The question of the relationship between these early fossil species and the hominin
lineage is still to be resolved. From these early species, theaustralopithecines arose around 4 million years
ago and diverged into robust (also called Paranthropus) and gracile branches, one of which (possibly A.
garhi) probably went on to become ancestors of the genus Homo. The australopithecine species that is best
represented in the fossil record isAustralopithecus afarensis with more than one hundred fossil individuals
represented, found from Northern Ethiopia (such as the famous “Lucy”), to Kenya, and South Africa. Fossils
of robust australopithecines such as A. robustus (or alternatively Paranthropus robustus) and A./P. boisei
are particularly abundant in South Africa at sites such as Kromdraai and Swartkrans, and around Lake
Turkana in Kenya.
The earliest members of the genus Homo are Homo habilis which evolved around 2.3 million years ago.
Homo habilis is the first species for which we have positive evidence of the use of stone tools. As modern
humans spread out from Africa, they encountered other hominins such as Homo neanderthalensis and the so-
called Denisovans, who may have evolved from populations of Homo erectus that had left Africa around 2
million years ago. The nature of interaction between early humans and these sister species has been a long
standing source of controversy, the question being whether humans replaced these earlier species or whether
they were in fact similar enough to interbreed, in which case these earlier populations may have contributed
genetic material to modern humans. This migration out of Africa is estimated to have begun about 70,000
years BP and modern humans subsequently spread globally, replacing earlier hominins either through
competition or hybridization.
Species
Lived when (mya)
Lived where
Adult height
Adult mass
Cranial capacity(cm³)
Fossil record
Discovery / publication of name
Denisova hominin
0.04
Russia
1 site
2010
H. antecessor
1.2 – 0.8
Spain
1.75 m (5.7 ft)
90 kg (200 lb)
1,000
2 sites
1997
H. cepranensis
0.5 – 0.35
Italy
1,000
1 skull cap
1994/2003
H. erectus
1.8 – 0.2
Africa, Eurasia (Java, China, India,Caucasus)
1.8 m (5.9 ft)
60 kg (130 lb)
850 (early) – 1,100 (late)
Many
1891/1892
H. ergaster
1.9 – 1.4
Eastern and Southern Africa
1.9 m (6.2 ft)
700–850
Many
1975
H. floresiensis
0.10 – 0.012
Indonesia
1.0 m (3.3 ft)
25 kg (55 lb)
400
7 individuals
2003/2004
H. gautengensis
>2 – 0.6
South Africa
1.0 m (3.3 ft)
1 individual
2010/2010
H. habilis
2.3 – 1.4
Africa
1.0–1.5 m (3.3–4.9 ft)
33–55 kg (73–121 lb)
510–660
Many
1960/1964
H. heidelbergensis
0.6 – 0.35
Europe, Africa, China
1.8 m (5.9 ft)
90 kg (200 lb)
1,100–1,400
Many
1908
H. neanderthalensis
0.35 – 0.03
Europe, Western Asia
1.6 m (5.2 ft)
55–70 kg (121–150 lb) (heavily built)
1,200–1,900
Many
(1829)/1864
H. rhodesiensis
0.3 – 0.12
Zambia
1,300
Very few
1921
H. rudolfensis
1.9
Kenya
700
2 sites
1972/1986
Red Deer Cave people
0.0145–0.0115
China
Very few
2012
H. sapiens idaltu
0.16 – 0.15
Ethiopia
1,450
3 craniums
1997/2003
H. sapiens
(modern humans)
0.2 – present
Worldwide
1.4–1.9 m (4.6–6.2 ft)
50–100 kg (110–220 lb)
1,000–1,980
Still living
—/1758
BIBILOGRAPHY
WWW.GOOGLE.CO.IN
WWW.en.wikipedia.org/wiki/Human_evolution
WWW.GOOGLE.CO.IN/IMGHP
