Early Homo PDF

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Summary

Dr. Emily Dew. Lecture notes on Early Homo
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Description

Australopithecus & Paranthropus Review -

Slow, gradual increase in cranial capacity Trend towards a harder diet Possible stone tool use from 2.6 mya

Early Homo characteristics - Larger brains than early hominins - More sophisticated subsistence economy - The way they make a living is more sophisticated - Smaller teeth with thinner enamel

Homo Habilis - Found in east and south africa - 2.4 to 1.4 mya - Height: 3’4 to 4’5 - Weight: about 32 kg or 70 lbs - May be on the branch of evolutionary tree where Homo sapiens is located CHARACTERISTICS - Slightly larger brain - Smaller face - Slightly forward teeth Hominin brain & stone tools - First bone tools used by Au. africanus - Au. africanus has more developed frontal lobe than earlier Australopiths - Hominins after Au. africanus have an even more developed frontal lobe Frontal lobe - Development important for tool making and plasticity

Kanzi the Bonobo - Kanzi is a really intelligent ape and has a high aptitude for linguistics featured in a film Ape Genius - Cranial capacity is similar to early Australopiths - Scientists use kanzi in experiments to test stone tool making capacity

Toolmaking experiment

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First experiment - Demonstrate with sharp plate that one can cut through a rope - Place favorite food in a box and tie it shut with rope - Then gave kanzi stone flakes to choose from - He learned to use it as a tool Next level was using thicker ropes - For sharper flakes - Kanzi succeeded about 90% of time Third level - Kanzi learned to make flakes by knocking rocks together - Used a hammerstone Innovated other methods - Smashed stone on concrete to make flakes - Threw one stone at another when outside - He came up with these methods independently Wasn’t able to - Strike at optimum angle to create best flakes - Make tools as refined as even the simplest Oldowan tools

Kanzi experiment is an example of experimental archaeology Toolmaking and Intelligence - Australopiths such as Au. africanus have more developed frontal lobe - They also have larger brain size than apes after 2.6 mya except for P. aethiopicus - Homo? Could they have made tools - Earliest homo: H. habilis was found in same area with stone tools 2.3 mya - Larger brain 600 cc - Brain also more human-like - Endocasts show evidence of hemispherization - Endocast is a model of an interior - Hemispheres involved wit - Evidence of Broca’s area in frontal lobe - Involved with language production - Wernicke’s area in parietal lobe - Involved with comprehension - Probably was capable - Parietal lobe accounts for most of brain size difference between Homo and modern humans - Major brain organization differences between Australopithicus/Paranthropus and early Homo - Spatial processing is involved in this region - Important, for instance, for angling to make better shaped flakes From Au. afarensis, africanus, P. boisei/robustus, H. habilis, and modern humans brain to body ratio increases from 280 cc/meter to 850 cc/meter

Early Homo anatomy - More efficient bidepedalism - Larger brain - Smaller teeth - Gracile face - Molar 1>M2>M3 Compared to Australopithicus/Paranthropus - Bipedal - Smaller brain - Large teeth - More robust face - Molar 3>M2>M1 Early Homo tool use - Processing meat - Cutting natural materials - hunting(?) - Recent evidence suggest Oldowan toolmakers got some of their meat through scavanging Scavenging - Many animals in savanna - Many killed by large predators and others die naturally during dry seasons - Tools can be used to cut and run - Takes intelligence - Listening to ‘kill calls’ from predators - Watching skies for vultures - Learning locations of leopard feeding trees - Requires planning and understanding behavior patterns in other animals - Evidence - Cutmarks often on bones from less meaty parts - Indicates early Homo got to it after other predators - Tool cutmarks found superimposed over animal tooth marks - Animal leg bones smashed to extract marrow Scavenging vs Hunting Debate Pro-hunting - Taphonomic evidence suggest hominins had primary access to carcasses - Chimps hunt small game Pro-scavanging - Oldowan tools too small and heavy to be carried around - Toolmakers didn’t have cognitive capacity to be large game hunters

- Taphonomic evidence for scavenging Probably a combination of both Ancestral search - Early Homo found first in east africa - Uncertainty about relationships with Au. africanus and afarensis and garhi - Au. garhi probably early ancestor to Homo - Nicknamed first engineer About 2.5 mya there were about two evolving species of hominids Humans and chimps evolving independently for about 7 million years Lucy was a biped Bipedalism doesnt require a savanna setting...