Anthro 7: Week 6
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Anthro 7: Week 6
Complex foraging likely linked to
-reduced sexual dimorphism
-more dependence on learning
-longer juvenile period
-longer life span
-extensive male investment
-male-female pair bonds
: S. tchadensis; O. tugenensis; A. ramidus
The shift from bipedal apes to Homo begins
Homo rudolfensis and Homo habilis main traits compared to Australopithocenes
Slightly larger brain (but may be proportional to an increase inbody size – this is uncertain)
Teeth are smaller with thinner enamel
Dental arcade is more parabolic (less subnasal prognathism)
Skulls more rounded
• Creatures appear in Africa with
Large, robust bodies
Long legs and short arms
Slower growth rate
Reduced sexual dimorphism
Early Homo ancestral traits
-narrowing behind eyes
Early Homo derived traits
-horizontal ridge on back skull
-larger brow ridges
-smaller, less protruding face
Post-cranial skeletons tell us a lot about H. ergasterbodies
• The adults were quite tall (male 6’)
• Long legs, narrow hips, narrow shoulders
• Committed bipedality
• Robust & heavily muscled
• Shorter arms than earlier
• Sexual dimorphism reduced
H. ergaster teeth well suited for
biting and tearing food(like raw meat)
H. ergaster controlled fire
• At Swartkrans, burned animal bones found with H.ergaster fossils
-camp fires made
Hominids moved into Asia
-about 1.6 mya
-larger brow ridges
-sides of skull slope more steeply
-point at back of skull more pronounced
Evidence of Meat Eating
Stone tools and bones found in Olduvai. Study of formation of kill sites. Tool marks on bones
Evidence of Scavenging
Cut marks on a variety of bones. Cut marks on top of carnivore tooth marks.
Homo ergaster Morphology
-Narrowing of braincase,
-smaller jaws and molars,
-Larger brain than earlier humans.
-Fully adapted for terrestrial life (no trees). -Slower juvenile development.
-No evidence of spoken language.
Homo ergaster Tools
1.6-1.4 mya ergaster improved upon Oldowan tools.
-Added stone biface (Mode 2 innovation).
-Could likely control fire.
Homo erectus Tools
Lack of Mode 2 tools related to different cognitive abilities than H. ergaster or to differences in materials available for toolmaking
800-500 kya. Evidence comes from areas as diverse as Spain and Zambia. Possibly coexisted with H. erectus.
Homo heiderlbergensis Morphology
-Larger brains (1200-1300)
-more rounded skull
-sides of skull more vertical
-Large brow ridges
-thick cranial bones
-large, prognathic face
-Only 3 feet tall.
-Very small brains.
-Isolated on Indonesian island. dwarfism.
H. heidelbergensis hunted
-bones of mammoths and wooly rhino found at base
-bones have been sorted by body parts
H.heidelbergensis tool use
-striking large, symmetrical flakes from core
-Levallois technique (mode 3)
-Europe and western Asia.
-Mode 3 tools (mousterian).
-Purposeful burial of the dead.
-shelter in natural rock caves
-"cave men" of popular culture
-Double arched brow ridges.
-Large cranial capacity (1400).
-Robust, heavily muscled bodies.
• H. ergaster originates inAfrica
• H. ergaster ---->H. erectus inAsia
• H. ergaster ---> H.heidelbergensis in Africa
• H. heidelbergensis moves intoAsia & Eurasia
• H. heidelbergensis----> H.neanderthalensis in Eurasia
• H. heidelbergensis ----> H.sapiens in Africa
• H. sapiens moves out of Africaand replaces all
-dates to 6 mya
-hominin with a mix of chimpanzee and human traits.
-the tooth enamel is thick, like that of humans
-shape and size of their teeth are more chimpanzee-like
-the oldest hominin ever found, dating from about 7 to 6 million years ago
-relatively flat face,
-5- 6 milion years ago
-brain and body size similar to modern chimps
-large canines compared to humans
-large sagittal crest
-flaring zygomatic arches (cheekbones)
Main features of bipedality and functionality
-wide ilium of pelvis
-Femur - long femoral neck and slant
-placement of foramen magnum
Evidence of bipedality
Adaptive advantages of bipedalism
1. Reduce heat
-less surface area
2. Freeing hands to do things or carry things
-pronounced sexual dimorphism,
-postcranial features that are adaptations to arboreality,
-and small brain sizes (with the exception of A. rudolfensis)
-The paranthropines are similar to the australopithecines from the neck down, but they had
-massive cheek teeth and jaws for chewing tough plant materials
- a skull modified to carry the enormous muscles needed for this type of chewing.