10 - evolution of subsistence behaviours Flashcards
three major patterns of human subsistence
foraging/gathering - plant foods, insects, eggs
hunting - meat and marrow - opportunistic or systematic
scavenging - meat and marrow
not mutually exclusive
subsistence, biology and behaviour interrelationships
changes in morphology
- e.g. bipedalism will influece food procurement
- food acquisition must have also influenced biology and behaviour e.g. tooth size, co operation
Interrelationship (subsistence, biology and behaviour) example
Homo erectus/ergaster and meat eating
- from irregular exploitation to regular part of diet
- these species represent a large shift in anatomy from previous hominins (larger body and brain - needs more nutrients)
subsistence behaviour can be interpreted from:
- archeological evidence
- ethnographic parallels
- ethnoarchaeology
- primate and animal models
- fossil morphology
- trace element analysis
Archeological evidence - plant remains
plants do not survive well in the fossil record
-pollen gives general profile of available plants - but not what was eaten
- seeds survive well
Parts of plants survive in restricted circumstances
- when desiccated e.g. in dry desert conditions
- in acidic, anaerobic deposits (bogs)
- when burnt as part of cooking and preparation process
archeological evidence of hunting
wooden spears from schoningen Germany c300,000 ya
- simple sharpened poles
- bitched horses found at same site
archeological evidence bones and teeth
bones and teeth most likely to survive due to high mineral content - but don’t necessarily show hominin diet
other problems with bones
- collections of bones may be due to natural collecting e.g, water action (seen at Olduvai) or due to activities of other animals
- it is difficult to differentiate hunting vs scavenging as butchery marks may be identical
- if previously food for animals then scavenged by hominin - tool marks may overlay tooth marks (difficult to tell)
archeological evidence for meat eating (not tools)
cut marks on bovid tibia mid shaft = traction of marrow from bone
-asutalopithecus gahri? c 2.5 mya
Stone tools new findings
Dikika, Ethiopia
- cut marks found on bones
- 3.4. ya
- concurrent with Australopithecus afarensis
- earliest stone tools
- evidence of butchery?
- evidence of taphonomy? e.g. crocodile bites
Canibalism?
cut marks on neanderthal bones suggest possibility of cannibalism.
- Goyet (Belgium)
- distinct evidence for butchery acticitues
- 4 bones used for retouching stone tools
- diversity in mortuary behaviour
alternatively - ritual of defleshing bones?
tool use
have assumed t be related to meet eating (scavenging, hunting, butchery) - evidence in upper paleolithic artwork of organised hunting?
Microscopic analysis of wear patterns can indicate use - experimental studies suggest wear patterns differ based on worked material
coprolites - fossil feces
mainly for later stages of human evolution.
- dietary components and DNA can be analysed
- also a good source of pollen
ethnographic parallels
studies of behaviour in modern hunter-gatherers
e.g. inuit
- adaptability
- social organisation
- subsistence strategies
ethnoarchaeology
ethnoarchaeology - study and then return to excavate modern hunters-gatherer sites to examine transfer of refuse into the archaeological record
e.g. look at how food is obtained, transported and how rubbish is discarded
primate models
primates mainly social carnivores e.g. tai forest chimps hunt co-operatively and systematically for colobus monkeys
studies indicate the importance of the role of hunting in primate and hominin social evolution
fossil morphology (1)
animals relative gut size indicated by the size and shape of its ribcage can indicate diet
e.g. Australopith guts large, like most apes, indicating a mostly herbivorous diet
e.g. Homo ergaster had a reduction in gut size (consumption of meat?)
also: massive increase in brain size
- more protein to fuel brain
BUT brains began increasing ealier
Fossil morphology (2)
patterns of tooth wear and abrasion can indicate diet.
changes in tooth size and proportions also related to diet and cooking food?
difference in facial skeleton - difference in diet?
e.g. muscle attachment sites between robust and gracile species
trace element analysis: bones and teeth
certain trace elements and isotopes reflect diet
e.g. strontium levels decline through the food chain - strontium higher in herbivores
carbon and nitrogen levels can help differentiate between protein sources
e.g. terrestrial vs marine
subsistence strategies early hominins
Australopiths:
- probably mainly vegetal diet (funnel shapes thorax ‘Lucy’)
- dental and morphological adaptations of paranthropines to eating hard objects
Some evidence of meet eating
e.g. Australopithecus gahri associated with tools and bones w cut marks
e.g. Australopithecus robustus have isotope evidence that eating some animal protein (termites?)
subsistence strategies homo habiliis (early hominin)
1st finitely associated with stone tools?
oldowan culture - crude pebble tools
no clear evidence of hunting - probably scavenging
possibly breaking bones open with tools to get at bone marrow
subsistence strategies later hominins (1)
Homo ergaster/erectus
-evidence of meat eating
e.g. KNM-ER 1808 - vitamin A poisoning
- scavenged, hunted (may have been opportunistic)
- meat eating important further north of equator, contributed to expansion out of Africa?
subsistence strategies later hominins (2)
Later Homo ergaster and Homo heidelbergensis
-may have used fire and traps
- injuries of neanderthals suggest they hunted large game
- probably less planning than modern humans
subsistence strategies Homo sapiens
- more complex strategies
- competent, efficient, purposeful hunters
- possibly related to planning and development of more complex communication/language?
- more varied diet - exploitation of marine resources etc
