close

Вход

Забыли?

вход по аккаунту

?

Human Evolution

код для вставкиСкачать
Apes to Man
Human Evolution
Human evolution is characterized by
several types of changes in phenotype:
Note: obviously, these aren't the only
phenotypic changes characteristic of
the human species, but are more
noteworthy in regards to human
evolution.
Changes in brain size & skull
shape
•
•
Smaller to larger brain capacity
Spinal insertion moves from rear to base of skull
Comparative Brain Sizes
Hand Shape
• Development of more
flexible opposable
thumb
• Allowed advanced
tool use
Pelvis shape
•
•
Allowed early
hominids to
stand & walk
upright
Gave advantage
of being able to
see around
them on the
savannah
Spine Shape
п‚·Changed
from "C"
shape to "S"
shape
Jaw Size
•Jaw has reduced in size, reflecting changes in species diet
•Size of teeth have generally decreased, especially canines
Hominid changes over time
Timeline of human ancestry
~ 14-16 Million Years to
(?) - Ramapithecus
& Proconsul
• Earliest Ape-like
ancestor.
• Did not walk upright
• Similar in size to the
chimpanzee, but
stockier
Genus Australopithecus
• ~ 3.5 - 1 million years - Genus
Australopithecus
• Several Species of this genus including
– A. afarensis, A.africanus, & A. boeisi
• Earliest is Australopithecus afarensis
• Very much apelike with an important feature.
Was able to walk upright
Australopithicenes
Australopithicenes
Homo Habilis
• ~ 2 - 1.5 million years - Homo
habilis "handy man".
–Larger than Australopithecus
–Larger brain
–Was first to use stone tools.
Homo habilis
Homo habilis contd.
Homo erectus
• ~ 1.5 Million years - ~ 80,000* years .
Homo erectus.
–Larger than H. habilis
–Larger brain
–Smaller face
–Was the first to use fire
–Allowed man to "break out" of Africa into
Europe & Asia
Homo erectus
Homo neanderthalis
~130,000 - 30,000 years. Homo
neanderthalis "Neanderthal man"
– Probably not a direct ancestor - but another
offshoot from H. erectus
– Shorter, stockier, stronger than modern man.
Adapted to ice age.
– Larger brain size than modern man.
– Buried dead with flowers - first evidence of
religeous/symbolic thinking.
H. neanderthalis
“Modern” man
• ~ 100,000 years to present - Homo
sapiens (modern man).
• Appears to have originated from H.
erectus in Africa, then migrated outwards
to Europe & Asia.
• Replaced existing species H. erectus & H.
neanderthalis
“Radiation” theory of H. sapien
evolution
“Parallel” theory of H. sapien
evolution
Current phylogeny of H. sapiens
How to make a human:
• Millions of years
ago, a majority of
northern Africa
was rainforest.
Ancestors to
man
Rapapithecus
and Proconsul,
were full arboreal
apes living in
these forests.
Changes
• However,
approx. 5
mya the great
rift valley
formed in
east central
Africa.
Problems…..
• The effect of this rift was to…
– Isolate the ape population from their peers in the west.
– The rift also created a “rainshadow desert” to its leeward
side.
Change of environment.
This change in precipitation
changed the landscape of
the region from rainforest
to savannah. The apes
needed to develop a new
form of transportation
since they could no
longer brachiate through
the trees. Thus, they
evolved the ability to walk
upright.
Документ
Категория
Презентации
Просмотров
18
Размер файла
6 517 Кб
Теги
1/--страниц
Пожаловаться на содержимое документа