Looking%20at%20Human%20Evolution

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Looking at Human Evolution
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Recall the classification system Kingdom
Animalia Phylum Chordata Class
Mammalia Order Primates
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Order Primates
Anthropoids (suborder Anthropoidea)
Suborder Tarsiiformes
Suborder Prosimii
Hominoids
Hylobatidae
Pongidae
Hominidae
New World monkeys
Old World monkeys
Lemurs
Tarsiers
Gibbons
Orangutans
Gorillas
Chimpanzees
Humans
Common Ancestor of hominids
Common Ancestor of hominoids (hominids and apes)
Common Ancestor of anthropoids
Common Ancestor of All Primates
Fig. 21.02
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tarsier
lemur
tarsier
http//nicoleeke.tripod.com/mainpagelemurweb.htm
lemur
Prosimians
http//www.tasikria.com/images/tarsier.jpg
gorilla
loris
http//www.kostich.com/pygmy_loris.htm
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Key Primate Traits

• Most key primate traits are directly involved or
  indirectly involved in brachiation (the swinging
  of limb to limb in trees)
• free movement of upper arm in any direction
• able to rotate arm bones and turn hand in a
  semi-circle (also for brachiation)
• 5 digits with opposable thumb for grasping
  branches and manipulating food
• Eyes in front of face (for 3-D vision)

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• Characteristics of organisms classified in Order
  Primates
• Strong and sensitive fingers
• Opposable thumb
• Brains larger proportionally
• Binocular (3-D) and color vision
• Omnivorous
• Usually give birth to 1 offspring at a time
  (allows for extended care)

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But at the Family level, humans branch off from
other primates
Kingdom Animalia Phylum Chordata Class
Mammalia Order Primates Family Pongidae
Kingdom Animalia Phylum Chordata Class
Mammalia Order Primates Family Hominidae
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Our branch

• We are on the ANTHROPOID branch (monkeys and
  apes, as opposed to prosimians lemurs and
  tarsiers)
• Prosimians probably resemble early arboreal
  primates.

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The Naked Ape

• Within the anthropoids, our group is the apes.
• Apes include gibbons, orangutans, gorillas, and
  chimpanzees (two species).
• Traits--large brain, long arms and short legs.
  Capable of brachiation, but only gibbons and
  orangutans are primarily arboreal.

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The Hominid-Ape Split

• Humans split from the ape line between 5 8 mya
• Molecular evidence puts the split between humans
  and apes at about 5-8 million years ago.

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Bipedality

• Why did bipedality emerge?
• Original Explanation
• This split between hominids and apes is thought
  to have resulted from the continuing drying
  trend, changing woodland into open plains. Any
  ape with a pre-adaptation for surviving in the
  plains would have an enormous survival advantage,
  and would be able to pass these traits to its
  offspring. Problem many fossil humans have been
  found in dense woodland or wooded lakeside
  habitats.

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Other Explanations

• Intrinsic Walking upright increased the range
  of vision, freed the hands for gathering, allowed
  for holding of children while standing.
• Heat regulation Standing upright vastly
  decreased body heating from the sun, decreasing
  heat stress. In this model, upright posture would
  have accompanied loss of body hair and the
  development of sweating as a means of evaporative
  cooling.
• Problem there is at least one highly successful
  group of monkeys baboons who made the
  transition toward savannah lifestyle, without
  becoming bipedal. Also, the earliest hominids
  appeared to live in wooded environments much like
  the ones where chimps live.

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Some anatomical ways we differ from Pongids
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Hand
Foot
Hand
Foot
(a) Lemur (Eulemur mongoz)
(b) Tarsier (Tarsius spectrum)
Hand
Foot
Hand
Foot
(c)
(b) Gorilla (Gorilla gorilla)
Woolly spider monkey (Brachyteles arachnoides)
Fig. 21.01
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So now a brief glimpse into human evolution
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Australopithecus afarensis

• Age 3.9 - 3.0 mya
• Bipedal
• Small brain
• Large, wide teeth
• Most complete early hominid
• Possible ancestor of all later australopithecines
  (A. africanus, A. robustus, A. boisei, A.
  aethiopicus, A. garhi)

http//www.rtg.wa.edu.au/loanpool/lucy.jpg
art
bones
prints
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A. afarensis artists renderings
http//www.gurche.com/webgraphics/ap_afar_106a_fs.
jpg
http//www.archaeologyinfo.com/images/afarensis.JP
G
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A. afarensis skeleton
http//www.wsu.edu8001/vwsu/gened/learn-modules/t
op_longfor/timeline/afar ensis/images/afarensis-th
ree-skeletons.jpeg
http//www.scienceinafrica.co.za/pics/origin2a.gif
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A. afarensis footprints
http//www.mnh.si.edu/anthro/humanorigins/ha/image
s/laetoli1.jpg
http//www.modernhumanorigins.com/hominids/laetoli
foot1.jpg
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Paranthropus robustus
Note the large (robust) cheeks, jaw, teeth, etc)
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Paranthropus robustus
http//anthro.palomar.edu/hominid/australo_1.htm
http//www.hunterian.gla.ac.uk/collections/museum/
hominid/australopithicus/ boisei_robustus/other_in
formation/other_information2.shtml
http//www.hunterian.gla.ac.uk/collections/museum/
hominid/ australopithicus/boisei_robustus/other_in
formation/other_information.shtml
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Homo habilis

• Age 2.3 - 1.6 mya
• Significantly larger brain size
• Clear evidence of tool use
• Brocas area (essential for speech) visible in
  brain cast

http//www.d.umn.edu/cla/faculty/troufs/anth1602/p
chomoha.html
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Homo habilis tools
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Homo erectus

• Age 1.8 - 0.3 mya
• First to leave Africa
• Traveled throughout Africa, Europe, and Asia
• Stone and bone tools
• May have used fire

art
bones
tools
travel
http//donsmaps.com/hominidimages/erectus.jpg
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H. erectus skeleton
http//www.anthro.univie.ac.at/virtanth/evo_links/
turkana20boy.jpg
http//donsmaps.com/erectus.html
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H. erectus artists renderings
http//www.amnh.org/exhibitions/atapuerca/africa/i
mages/19_erectus_mat_lg.jpg
http//www.baa.duke.edu/Classes/course_images/Homo
20erectus.jpg
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H. sapiens neanderthalensis

• Age 250,000-30,000
• Coexisted with H. sapiens sapiens
• Larger brain and body size
• Adapted to cold
• Used fire
• Buried dead
• Cared for wounded and elderly

http//www.astrosurf.org/lombry/Bio/crane-h-neande
rthal-laferrassie.jpg
art
bones
range
tools
culture
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H. sapiens neanderthalensis artists renderings
http//www.daviddarling.info/images/Neanderthal.jp
g
http//www.walespast.com/article_images/54-1l.jpg
http//www.prehistory.lu/images/neand.jpg
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H. sapiens neanderthalensis skeleton
http//www.amnh.org/exhibitions/atapuerca/meet.php
http//www.channel4.com/history/microsites/N/neand
erthal/facts/neanderthal_skeleton.html
http//www.biblestudy.org/basicart/skeletns.jpg
http//www.msu.edu/heslipst/contents/ANP440/image
s/Kebara_2.jpg
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H. sapiens neanderthalensis culture
50,000 year old bone flute (neanderthal or modern
human?)
Burial site with flowers
http//www.msnbc.com/news/547058.jpg
http//www.msu.edu/heslipst/contents/ANP440/image
s/Shanidar_4_and_6.JPG
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Humans are Young

• As a species, Homo sapiens is only 300,000-50,000
  years old.
• In relation to several billion year history of
  the earth, this is an extremely small amount of
  time.

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H. sapiens sapiens

• Age 100,000 - present
• Cave art, sculptures, etc.
• Small teeth jaws
• Very high forehead, prominent chin

paint
sculpt
http//news.nationalgeographic.com/news/2004/10/ph
otogalleries/ homo_floresiensis_1/images/primary/f
lores_sapiens.jpg
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H. sapiens sapiens painting(Cro Magnon, caves
in France)
http//www.sanford-artedventures.com/study/images/
cave_painting_l.jpg
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H. sapiens sapiens sculpture
22,000 B.C.E.--ivory
http//www.tronchin.com/Art1A/lecture2.htm
22,000 - 21,000 B.C.E.--stone
http//www.tronchin.com/Art1A/lecture2.htm
12,000 B.C.E.--reindeer antler
http//www.talariaenterprises.com/product_lists/go
ddess.html
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• Cultural Evolution is by far the major force at
  work in changing humanity.
• Agriculuture began only about 11,000 years ago.
• Modern science began only about 500 years ago.
• The industrial revolution was 200 years ago.

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One final notehumans have evolved through
variation, mutation, and natural selection like
all other species.And we continue to evolve
today. Yet, keep in mind that evolution occurs
in a branching fashion, With some paths diverging
and evolving differently depending on
environmental conditions, the variations
that arose etc. Some paths lead to dead ends
and those human species have gone extinct.
Remember the branching tree and not a linear
progression.
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Hominid Family Tree
H. sapiens sapiens
H. sapiens neanderthalensis
H. sapiens (archaic)
H. erectus
H. ergaster
A. boisei
A. robustus
Homo habilis
A. aethiopicus
A. garhi
A. africanus
A. afarensis
Kenyanthropus platyops
Ardipithecus ramidus
Australopithecus anamensis
http//site.voila.fr/levolution/originehomme.htm
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The End(but not really!)
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