Human Evolution
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According to the theory
of plate tectonics, the
continents embedded in
underlying plates on the
earth’s surface have
moved in relation to one
another over the history
of life on earth. They are
still moving today.
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Climate changes led to the appearance of primates
about 65 million years ago.
These were small, arboreal, nocturnal, insect eaters.
About 23 million years ago, hominoids, the primates
that include all living and extinct apes and humans
began to appear in Asia, Africa, and Europe.
DNA studies have confirmed that the African apes
are our closest living relatives.
Bipedalism preceded brain expansion and played a
pivotal role in setting us apart from the apes.
 In
the past 35 years, studies have
confirmed that the African apes
(chimpanzees, bonobos, and gorillas) are
our closest living relatives.
 Between 8 and 5 million years ago,
humans, chimpanzees, and gorillas
began to follow separate evolutionary
courses.
 Humans and their ancestors are distinct
among hominoids for bipedalism, a form
of locomotion on two feet.
 Dated
to 4.4
million years ago.
 The remains show
that some of the
earliest bipeds
inhabited a
forested
environment.
 Position
of foramen magnum
•Shape of spine
•Shape of pelvis
 The
genus including
several species of
early bipeds from
southern and eastern
Africa living between
about 4.3 and 1.1
million years ago, one
of whom was directly
ancestral to humans.
 Known
for the
rugged nature of
their chewing
apparatus (large
back teeth, large
chewing muscles,
and bony ridge on
their skull tops for
the insertion of these
large muscles).
 Members
of the genus Australopithecus
possessing a more lightly built chewing
apparatus.
 Likely had a diet that included more meat
than that of the robust australopithecines.
human.”
 The first fossil members of the genus
Homo appearing 2.5 million years ago,
with larger brains and smaller faces than
australopithecines.
 May have been a tertiary scavenger.
 “Handy
 The
first stone tool industry.
 Marked the start of the Lower Paleolithic (or
Old Stone Age) beginning about 2.6 million
years ago.
human.”
 A species within the genus Homo first
appearing just after 2 million years ago in
Africa and spreading through the Old
World.
 Had a brain close in size to that of
modern humans.
 Had sophisticated behaviors including
use of fire for warmth, cooking, and
protection.
 Made smaller and lighter tools.
 “Upright
 Between
400,000 and 200,000 years ago,
evolving humans achieved the brain
capacity of contemporary Homo sapiens.
 Several variations of the genus Homo
existed around this time, and they are
ancestral to both Neandertals in Europe
and the Middle East, and Modern
Humans.
A
distinct group within the genus Homo
inhabiting Europe and Southwest Asia
from approximately 125,000 to 30,000
years ago.
 Represented as the classic cavemen.
 They had modern-sized brains with faces
and skulls that were very different from
later fossilized remains.
 Associated with the Mousterian tool
industry.
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The use of fire was essential to their survival in cold
climates.
They lived in small bands or single family units, in the
open and in caves.
They likely used language to communicate.
They buried their dead, reflecting ritual behavior.
Fossil remains of an amputee discovered in Iraq and an
arthritic man excavated in France imply they cared for
the disabled.
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The tool industry of the Neandertals and their
contemporaries of Europe, Southwest Asia, and
northern Africa from 125,000 to 40,000 years ago.
Mousterian tools are lighter and smaller than those of
earlier traditions.
Previous industries obtained only two or three flakes
from an entire stone core, Mousterian toolmakers
obtained many smaller flakes, which they retouched
and sharpened.
 The
last part (40,000 to 10,000 years ago)
of the Old Stone Age, featuring tool
industries characterized by long slim
blades and an explosion of creative
symbolic forms.
 Evidence
indicates that at least one
population of archaic H. sapiens evolved
into modern humans.
 Whether this was due to the biological
evolution of a new species or a
simultaneous worldwide process
involving all archaic forms is debated.
 The
hypothesis that modern humans
originated through a process of
simultaneous local transition from Homo
erectus to Homo sapiens throughout the
inhabited world.
 The
hypothesis that all modern people
are derived from a single population of
archaic H. sapiens from Africa.
 These H. sapiens replaced other archaic
forms due to superior cultural
capabilities.
 Also called the “Eve” or “Out of Africa”
hypothesis.