Human

evolution

By

Abishekvarun
Before Homo, Early evolution of
Primates Oligocene primates
• Parapithecus was a primitive primate ancestral to man,
apes and monkeys. It was very small squirrel-like
earliest primitive monkey having tarsier-like
appearance. The jaw was conical, the two halves
converging at an angle of 33 degrees. These creatures
were probably adapted for arboreal mode of life and
had opposable thumb, forwardly directed eyes and
reduced snout
Pliopithecus
• Is represented by several well preserved fossils from
Egypt and Europe. It shows affinity with pongids but
the mandibular symphysis is longer and more
prosimian type. A shallow simian gap is present. Body
is gibbon-like in the morphology of pelvis, vertebrae
and sternum. Limb bones are surprisingly primitive,
resembling those of prosimians while the general body
proportions are like those of monkeys
Dryopithecus (=Sivapithecus)
• Was ancestral to Orangutan, chimpanzee and gorilla
and resembled gibbon in stature Most of the fossils are
represented by jaw fragments and teeth, with few
exceptions such as a humerus and an ulna from France
and a femur from Germany The three genera,
Dryopithecus, Sivapithecus andProconsul have been
placed in the subfamily Dryopithecinae
Sivapithecus
of Ramapithecus, whose fossils have been recovered
from the same deposits in fossils were discovered from
Siwalik Hill by Lewis in 1934 and are represented by
fragments of jaw and teeth. The small size of teeth and
canines and simplified molars suggest a transitional
stage to hominid type of dentitionthe Siwalik Hills and
date from 17 to 8 million years old
 Australopithecus africanus, “the
southern ape”
• Is the most primitive of Australopithecines that existed between
years ago Fossil of a 5-year old boy (Taung baby) was discove
Africa by Prof. Raymond A. Dart in 1924 It was 5 feet tall and w
Vertebral column had a lumbar curve and pelvis was broad. Fo
was placed under the skull. Teeth human and dental arch smo
Palate seems to be shallow anteriorly and deep posteriorly. Ca
and simian gap absent. Premolars and molars greatly enlarged
incisors
• Cranial capacity was 450-700 cc. Face was prognathous with
long palate but less prominent eyebrow ridges and without
chin. Orbits were large and rounded. Nasal bones were flat,
giving the short face a dish-shaped appearance.
• Gracile form and probably a descendant of A.
Africanus One almost complete skeleton of a
female named “Lucy” was discovered from Afar
(Ethiopia) by Donald Johanson in 1973 It was dated
at 3.5 million years. It was about 5 feet tall and
walked erect and had an arched foot to support the
bipedal gait. Cranial capacity was 400-500 cc
Canines were small with thick layer of enamel and
molars were designed to grind tough material
Ardipithecus ramidus
• Is represented by 21 specimens found near Lake
Turkana and from Aramis in the Awash Valley in 1995.
Dated back to 4.4 million years, it perhaps walked
erect. It is believed to be a sister species of anamensis
The following three species were robust forms of
Australopithecus, sometimes identified by the separate
generic name, Paranthropus, as they seem to have
descended from a common ancestor-
Homo habilis
• Lived 1.85- 2.6 million years ago and walked erect
Fossils were discovered by Louis Leakey in 1959 from
Olduvai Gorge in Tanzania, where later several teeth,
jaw and skull fragments were discovered. Its premolars
and molars were smaller and anterior teeth larger It
was 140 cm tall, with cranial capacity of 700 cc and
human teeth It was a habitual biped and probably
ancestral to all Homo It hunted small animals and was
a scavenger of large carcasses
• It was closely related to A. Africanus
but was more advanced in features
and occupied similar ecological
niche
Homo erectus
• Fossil remains dating from 1.9 million years to about
250,000 years discovered from Java, China and later
Europe and Africa are collectively known as Homo
erectus, the archaic man that had larger brain and
used stone hand axes Supraorbital ridges are
prominent, with an indented area behind them It had
massive face that projected below and heavily built
mandibles, without a chin that were moved by strong
masseter muscles
• Teeth are similar to ours but incisors
are slightly larger and shovel-
shaped having enlarged pulp cavity,
an adaptation for hard chewing
Pithecanthropus erectus (Java Man)
• Was discovered by a Dutch army
officer, Eugene Dubois in 1891
Skull cap, few teeth and a femur
are known. Forehead was low and
supraorbital ridge. Cranial
capacity was 775-900 cc. Height
was about 5 feet and it walked
erect efficiently. Bones of the skull
were extraordinarily thick. Face
was prognathous, chinless and
skull flat on the top and projected
behind
Neanderthal Man
• Later, fossils of about 200 individuals were unearthed from
70 sites in Austria, China, France, England, Germany,
Greece, Italy, Iraq, Israel, Java, Russia and Yugoslavia The
species lived between 200,000 and 30,000 years ago. The
average cranial capacity was 1450 cc, which is greater
than in modern man, but the brain was large posteriorly
and ventrally They were stout and powerfully built people,
weighing over 80 kg and having an average height of 5’6”
Long bones were thick, slightly curved and had large areas
for muscle attachment Forehead was low and slanting,
eyebrow ridges were heavy and cheek bones were large.
Nose was broad and chin was absent
• Stature was robust and completely upright Teeth were
large They were cave dwellers living in the most adverse
environmental conditions and used fire, made stone
tools and crude carvings and practiced burial There is
strong evidence of ritualistic practices, religious beliefs
and ceremonious burials The classic Neanderthals come
from fourth interglacial period in Europe and had stocky
and rugged stature, broad nose, stout mandible,
projecting occipital region and no chin
 • Humans (Homomodern sapiens,
Homosapiens meaning
Anatomically,
'thinking
characterized by theman'
humans can generally be
or of their skeleto
lighter build
'wise man')
comparedor modern
to earlier
very large brains,
humans. Modern humans ha

humans (sometimes Homo

sapiens sapiens) are the
most common and widespread
Anatomically, modern species
humans can of primate,
generally be and the last
surviving
characterized by the lighter species
build of their skeletonsof the genus
compared to earlier humans. Modern humans have
very large brains, Homo and the broader
Australopithecine.
• The name Homo sapiens was applied in 1758 by the
father of modern biological classification (see
taxonomy), Carolus Linnaeus. It had long been
known that human beings physically resemble the
primates more closely than any other known living
organisms, but at the time it was a daring act to
classify human beings within the same framework
used for the rest of nature. Linnaeus, concerned
exclusively with similarities in bodily structure,
faced only the problem of distinguishing H. Sapiens
from apes (gorillas, chimpanzees, orangutans, and
gibbons), which differ from humans in numerous
bodily as well as cognitive features. (Charles
Darwin’s treatise on evolution, On the Origin of
Species, would come 101 years later.)
• Since Linnaeus’s time, a large fossil record has
been discovered. This record contains numerous
extinct species that are much more closely related
to humans than to today’s apes and that were
presumably more similar to H. Sapiens
behaviorally as well.
Thank you