Transcript Human Evolution - Monroe Township School District


2 Divisions of
Primates



1. Anthropoid primates
2. Prosimean primates
Characteristics:



Nails (no claws)
Prehensile hands and
feet (grasping)
Color vision and depth
perception

Include:

marmosets
Monkeys
Apes
Humans

Brain size



 Large relative
to their body
size
Opposable
thumbs
 Similar dental
formula

 number and
arrangement
of teeth






Bipedalism – Ability to walk on 2
feet
Aligned toes = Bipedalism
Enlarged brain =Vertical face
Areas for speech in the brain
S- shaped spine
Bowl-shaped pelvis

Include:



Lemurs
Lorises
Tarsiers


Draw a Prosimean skeleton, Anthropoid
skeleton and a human skeleton
Draw the basic bones




Pay special attention to the skulls
Use the same colors for homologous parts in
the three skeletons
Highlight the key features of each primate that
makes them successful and unique
How does this make them successful?

Scientists who study fossil
evidence of human evolution
 Construct
models of how and
when different stages of human
evolution occurred



Hominids include humans and extinct
humanlike primates
The oldest known hominid fossils are between
6 and 7 million years old
First fossils found in Africa

Two hypotheses have been proposed
for the evolution of Homo sapiens

“African replacement” hypothesis
 Also called Out of Africa, Recent-AfricanOrigin

“Multiregional origin” hypothesis



Members of the genus Homo made repeated
long-distance migrations out of Africa
beginning 1.8 million years ago
H. sapiens emerged from Africa about 150,000
years ago and spread across the Near East,
Europe, and Asia
The dispersing H. sapiens populations replaced
all other hominids



H. erectus emerged from Africa 1.8 million
years ago and spread across the Near East,
Europe, and Asia
Continued migrations and interbreeding
occurred among widespread H. erectus
populations
Regional populations of H. erectus evolved into
H. sapiens





Oldest known genus of hominids
Lived more than 4 million years ago
Knee joints- Allow bipedalism!
Australopithecus anamensis
Australopithecus afarensis – believed to have given
rise to:
A. africanus
 A. robustus
 A. boisei
 Modern Homo sapiens


more than 1 million years ago

!

!


Fossils of nearly half
complete early hominid
Australopithecus afarensis
suggests hominids became
bipedal before their brains
began to dramatically
enlarge



Recent discovery
Not clear whether it was bipedal
4.4 million years old
Hominid phylogenetic tree is
very branchy in appearance
 Representing species died out,
leaving no descendants.






Ancestors to modern humans
Larger brains than australopithecines
May have had speech
Started to develop tools
Homo erectus- potential first hominid to leave Africa
Homo habilis
Homo erectus



Now extinct
Hypothesis- Homo sapiens, being superior to
Neanderthal man, ran him off the planet.
New hypothesis- more complicated






Neanderthals may have mixed with the ancestor of modern
man
We could be carrying Neanderthal genes.
Heavy bones
Thick brow ridges
Protruding teeth
Used shelters, tools, and clothing



Cro-Magnons coexisted with
Neanderthals in Europe and
the Middle East for as many
as 50,000 years
Cro-Magnons had domed
heads, smooth brows, and
prominent chins
30,000-year-old Cro-Magnon
artifacts include:
Bone flutes
 Ivory sculptures
 Evidence of elaborate burial
ceremonies


Evolved about 800,000 years ago

A) Neanderthals
 Were early Homo sapiens
 They may be ancestral to modern humans OR
 They may have died out and been replaced by modern
humans


1. some anthropologist think H. sapiens
evolved in PARALLEL from populations of H.
erectus all over the world. (interbreeding)
2. some anthropologists propose that H. sapiens
DESCENDED from H. erectus in Africa and
then dispersed across Earth.