Human Evolution - Class 11 Video Lecture

the story of human evolution in this
module we learn about the evolution of
human beings around 5.6 million years
ago around 5.6 million years ago the
first human-like creatures appeared on
the earth however the first human beings
resembling our modern day version walked
the earth around 1 lakh 60,000 years ago
the lifestyle of early human beings is
best understood from human fossils stone
tools and cave paintings discovered
during archeological excavations and
research some fossils have contributed
immensely in archaeologists
understanding the lives of early human
beings around 5.6 million years ago the
first hominids evolved from the
hominoids unlike their predecessors the
hominids had a larger brain upright
posture specialized hands and bipedal
locomotion or walked on two feet
hominids belong to the family home any
day Anna subdivided into several genus
of branches most important among these
are the Australopithecus or southern
eighth and Homo or man the former has a
smaller brain heavier jaws and larger
teeth as compared to the latter around
2.5 million years ago with the onset of
the Ice Age the world underwent major
changes in climate and vegetation these
changes led to the expansion of
grasslands and reduction of forest cover
this change resulted in the gradual
extinction of the early forms of the
Australopithecus genus which were
adapted to forests and further evolution
of the hamaji
which could survive in drier conditions
the term homo a Latin word means man the
homogenous first evolved into the Homo
habilis or tool maker the Homo habilis
evolved into the homo erectus or upright
man who then evolved into the homo
sapien or thinking man in contrast to
the fossils of Homo habilis and Homo
erectus those of Homo sapiens have been
found in several parts of the world like
France Borneo Australia and Africa the
place of origin of modern humans is
still a topic of debate because most of
the earliest evidence of the homo
sapiens has been found in africa the
question posed is was there a single
Center of human origin or multiple
centers two divergent views seek to
answer this question
regional continuity model and
replacement model scholars who advocate
the regional continuty model believe
that Homo sapiens originated in multiple
or different parts of the world and
evolved in their respective regions from
local archaic humans this theory
justifies the variations in humans in
different parts of the world however
scholars who advocate the replacement
model belief that Homo sapiens
originated in a single region Africa
later migrated to other parts of the
world and evolved in those parts they
replaced all other archaic humans in
those regions
thus it entails that all people today
share a relatively modern African
ancestry this theory justifies the
anatomical homogeneity amongst all the
humans in the world
let's recall about 36 million years ago
first primates emerged about 24 million
years ago a subgroup of primates the
homie noids emerged hominoids included
quadruped apes that walked on all four
feet but had flexible four limbs about
5.6 million years ago first hominids
evolved from the hominoids hominids had
a larger brain
upright posture specialized hands and
bipedal locomotion hominids belong to
the family Hominidae ana subdivided into
several genus or branches
Australopithecus or southern ape and
homo or man are two important geniuses
around 2.5 million years ago
Australopithecus genus became extinct
and Homo genus evolved Homo genus
evolved into Homo habilis toolmaker then
to Homo erectus upright man and finally
to homo sapien thinking man questions
are often raised about the place of
origin of modern humans two divergent
views answer this question regional
continuity model replacement model