Class Slides Set 15A
Bipedalism
Legs/Feet and Pelvis
Bipedalism
Legs/Feet and Pelvis
www.sciencedaily.com/releases/2008/05/080529140042.htm
www.guardian.co.uk/science/2008/jun/02/genetics.medicalresearch
http://www.sciam.com/article.cfm?chanID=sa003&articleID=0008EB7D-BC26-1138-BC2683414B7F0000
Arm swingingand
erect (bipedal)or
semi-erect walkingresulted in a number of
postcranial changes
Postcranial =
below the head(with bipeds)
behind the head(with quadrupeds)
Modern human
Postcrania
New World monkey
Understanding Physical Anthropology and Archaeology, 9th ed ., pp. 200, 429, 121
Apes
The ability to assume a fairly erect posture produced important
changes
Chimpanzee
The Primates, Time-Life (1974) p. 71
Bipedal Locomotion
Why bipedalism?
Understanding Physical Anthropology and Archaeology, 8th ed., p. 217
Possible Factors Influencing the
Initial Evolution of Bipedal Locomotion in Hominids.
Bipedalism
Bipedalism is related to tool use
Understanding Physical Anthropology and Archaeology, 8th ed., p. 217
Possible Factors Influencing the
Initial Evolution of Bipedal Locomotion in Hominids.
Humankind Emerging, 7th ed., p. 275
Positive Feedback Systems.
Acheulian biface (“hand axe”)
Understanding Physical Anthropology and Archaeology, 9th ed ., p. 239
Bipedalism
more about bipedalismand to tool use later
Bipedalism
Bipedalism also makes hunting
more energy efficient
Understanding Physical Anthropology and Archaeology, 8th ed., p. 217
Possible Factors Influencing the
Initial Evolution of Bipedal Locomotion in Hominids.
The Primates, Time-Life (1974) p. 44
Bipedalism
Seed and nut gatheringand
Feeding from bushes
Understanding Physical Anthropology and Archaeology, 8th ed., p. 217
Possible Factors Influencing the
Initial Evolution of Bipedal Locomotion in Hominids.
Bipedalism
Bipedalism and vision(visual surveillance)
Understanding Physical Anthropology and Archaeology, 8th ed., p. 217
Possible Factors Influencing the
Initial Evolution of Bipedal Locomotion in Hominids.
Humankind Emerging, 7th ed., p. 114
Eye Level and Sight.
Bipedalism
Bipedalism andLong-distance walking
Understanding Physical Anthropology and Archaeology, 8th ed., p. 217
Possible Factors Influencing the
Initial Evolution of Bipedal Locomotion in Hominids.
Bipedalism
Male help in
“provisioning”Owen Lovejoy “provisioning hypothesis”
Understanding Physical Anthropology and Archaeology, 8th ed., p. 217
Possible Factors Influencing the
Initial Evolution of Bipedal Locomotion in Hominids.
Humankind Emerging, 7th ed., p. 270
Pliocene Adaptations. (Lovejoy)
Bipedalism
Bipedalismand
other hominid traits
Understanding Physical Anthropology and Archaeology, 8th ed., p. 217
Possible Factors Influencing the
Initial Evolution of Bipedal Locomotion in Hominids.
Not on the chart
Bipedalism
body temperature
http://news.bbc.co.uk/sport1/hi/other_sports/1468591.stm
http://www.sunspot.net/sports/baseball/bal-te.sp.orioles18feb18,0,360173.story?coll=bal-utility-baseball
Bipedalism
R. Falk (1989) suggested that bipedalism resulted in the development of a cooling mechanism for the brain.
CA 31:2:187
Humankind Emerging, 7th ed., p. 268
Body Surface and Solar Radiation.
Understanding Physical Anthropology and Archaeology, 8th ed., p. 217
Possible Factors Influencing the
Initial Evolution of Bipedal Locomotion in Hominids.
Not on the chart
Bipedalism
may have beenan arboreal forest
adaptation
Video: Search for the First Human --
A Secrets of the Dead SpecialWeek 07
Understanding Physical Anthropology and Archaeology, 8th ed., p. 217
Possible Factors Influencing the
Initial Evolution of Bipedal Locomotion in Hominids.
Not on the chart
Bipedal walkingresulted in a number of
postcranial changes in the legs and feet . . .
The legs and feet . . .
feet become more foot-like
gibbons
bonobos chimps
gorillashumans
Campbell and Loy, Humankind Emerging, 8th ed, p. 138f
orangutans
orangutansgibbons bonobos chimps gorillas humans
Foot (pedal) anatomy.
Understanding Physical Anthropology and Archaeology, 9th ed ., p. 435
Humankind Emerging, 7th ed., p. 383
Grover Krantz.
Foot (pedal) anatomy.
Understanding Physical Anthropology and Archaeology, 9th ed., p. 436
Leg bones are much stouterand
have more pronounceddorsal ridges
(on the back)
Leg muscle structures change
Understanding Physical Anthropology and Archaeology, 8th ed., p. 224
Comparison of muscles that act to extend the hip.
Humans have developed a “closed-knee stance”
Humankind Emerging, 7th ed., p. 193
Closed-Knee Stance.
WT 15000 from Nariokotome, Kenya:
the most complete Homo erectus specimen yet found
Understanding Physical Anthropology and Archaeology, 9th ed ., p. 235
Humankind Emerging, 7th ed., p. 242
There is a lossof some mobility
and “prehensility”
in feet
Prehensility = the ability to grasp
White-handed gibbon
Understanding Physical Anthropology and Archaeology, 9th ed ., p. 131
A number of changes take place in the pelvis
. . .
• becomes shorter and wider . . .
• has a “distinct pelvic bowl” . . .
• and the muscle attachment ridges become heavier . . .
The Pelvis
• becomes shorter and wider . . .
• has a “distinct pelvic bowl” . . .
• and the muscle attachment ridges become heavier . . .
The Pelvis
Ossa coxae. (a) Homo sapiens.
(b) Australopithecus. (c) Chimpanzee
xx
Understanding Physical Anthropology and Archaeology, 9th ed ., p. 199
Pelvic girdles.
Understanding Physical Anthropology and Archaeology, 9th ed ., p. 435
• becomes shorter and wider . . .
• has a “distinct pelvic bowl” . . .
• and the muscle attachment ridges become heavier . . .
The Pelvis
Pelvic girdles.
Understanding Physical Anthropology and Archaeology, 9th ed ., p. 435
And the muscle attachment ridges one
the pelvis become heavier . . .
Ossa coxae. (a) Homo sapiens.
(b) Australopithecus. (c) Chimpanzee
xx
Understanding Physical Anthropology and Archaeology, 9th ed ., p. 199
The human os coxae, composed of three bones. (R)
Understanding Physical Anthropology and Archaeology, 9th ed ., p. 199
More on pelvic changes later, with the discussion of
Australopithecus(“southern ape”)
External tails are lost
Skeleton of a brachiator (gibbon)
Understanding Physical Anthropology and Archaeology, 9th ed ., p. 121
Continue on to Set #15B
The Upper Body
Modern human skeleton
Understanding Physical Anthropology and Archaeology, 8th ed., p. 223