What is special about human tool use?

What is special about human tool use?

What is special about human tool use?

• Over the last 4my humans have evolved from small-brained, fruit-eating, bipeds, to large-brained bipeds who dominate the planet

What is special about human tool use?

….we can’t live without them

What is special about human tool use?

Who were the earliest tool makers?

• Who were the earliest tool makers?

• What types of implements did they have?

• How were they made and used?

• What was life like for our early tool-making ancestors?

• How do early hominin tools compare with technologies among non-human animals?

• How did tools give hominins such an advantage in terms of survivability and increased reproductive success that was selected by evolution?

The tool must be:

• The tool must be:

• free of any fixed connection to the substrate
• outside the user's body at time of use
• not attached part of the users body,
• may or may not be animate

• The user must:

• hold or carry tool prior to use
• establish the proper and effective orientation between the tool and the incentive, (includes alteration of the form/ position/ condition of another object, organism, or the user)

• Tool manufacture:

• "any modification of an object by the user or a
• conspecific so that the object serves more effectively
• as a tool“ (Beck, 1980)

We are not alone!

Tool use in wild apes

Tool use hierarchy

Australopithecines

• Indirect evidence:  hand bones of A. afarensis (Lucy, 3mya) = apelike: curved phalanges, thin tips to the fingers and a short, non-opposable thumb

(left to right): end chopper, heavy-duty scraper, spheroid hammer stone, flake chopper; bone point, horn core tool or digger

Paranthropus boisei and H. habilis were contemporary at Olduvai for 1.4m years

• Paranthropus boisei and H. habilis were contemporary at Olduvai for 1.4m years

• Difficult to separate out remains –

• Who made tools? Hh/ Pb/ both?
• H. habilis = > brain size than Paranthropus boisei (Zinjanthropus) that Mary Leakey decided had to be the tool maker
• Paranthropus may have used them????

• Did one species scavenge prey off the other?

• Were hominins preying on hominins?

Experimental analysis

• Nick Toth:

• small flake:

• Slice through hide
• Dismembering, and defleshing (human teeth and fingers inadequate)

• large flake or chopper:

• Chopping residual dried meat from a scavenged carcass

• heavy core / unmodified cobble

• breaking bone to gain access to marrow or brain

• unmodified stone hammer and anvil: crack nuts

• antelope horns and large broken bones = digging implements

• manufacture of digging sticks achieved:

• sharp edges chopper - cutting a suitable limb from a tree
• flake for fashioning point
• rough stone surface for honing point

Microwear analysis

• Lawrence Keeley - 54 flakes from Koobi Fora (E. side of Lake Turkana, 1.5mya).  Evidence of use-wear on 9 tools: 4 - butchering, 3 – wood, 2 - soft vegetation

Significance of stone tools

• Small, sharp flake = technological and economic revolution  significant quantities of meat

• Digging sticks permitted efficient access to underground food resources, e.g. tubers

• Enriched diet & less seasonal = important in further expansion of the brain

1.9mya – c.300,kya

• 1.9mya – c.300,kya

• glaciations from 2.4mya

• intense climatic swings

• drop in global temperatures
• ocean levels dropped ca.100m – expose continental shelves & create land bridges

• out of Africa (by 1.8mya – SE Asia)

• …what allowed such phenomenal geographic spread and species longevity?

Oldowan: hit the stone = sharp flake you could cut with it

• Oldowan: hit the stone = sharp flake you could cut with it

• Acheulean: shaped implements for specific tasks, flaking all edges, worked to get longer, straighter and sharper implements

• Need expertise & knowledge of lithic technology
• Wear patterns – “habitual and systematic butchery, and especially the dismembering of large animal carcasses” (Schick and Toth)
• Strong dietary shift towards more
• meat consumption

Movius Line

• Acheulean tools were found throughout Africa, Middle East, Europe and W Asia, but, absent in Far East and SE Asia –

• Striking overlap with natural occurrence of bamboo

Role of shelter in geographic spread & species longevity

• 400,000 – 300,000mybp Terra Amata (under Nice)

• Homo erectus or H heidelburgensis?

• 1960’s by Henry de Lumley – ancient postholes & concentrated artefacts of several huts (6-15m long x 4-6m wide)

• De Lumley: roofs supported by 2 or more large posts, walls made of saplings and branches. Hold c.15 people

Role of fire in geographic spread & species longevity

• Terra Amata: in the centre of each reconstructed hut was a hearth (compact area of baked & discoloured sand), some hearths ringed by windscreen of stones

• No evidence of cooking, fires burnt for warmth

• Around one hearth impressions

• on the floor that were apparently

• made by animal skins, - did

• inhabitants sleep by the fire

• at night ?

Conclusion

• From 4mya to 400kya technology increasingly allowed hominin populations to adapt by manipulating, transforming their environment, rather than their biology, to survive and reproduce

• Technological developments, and particularly tool use transformed human ancestors from small brained, fruit eating, bipedal apes at the mercy of environmental change, to large-brained, cultured bipeds who dominate the planet