early-Pleistocene aquatic resources overlooked

[littor...@gmail.com]

Investigating the Signature of Aquatic Resource Use within Pleistocene Hominin Dietary Adaptations
Will Archer & David R Braun 2013 PLoS doi org/10.1371/journal.pone.0069899

There is general agreement:
the diet of early hominins underwent dramatic changes shortly after the appearance of stone tools in the archaeological record.
It is often assumed that this change is ass.x dietary expansion to incorporate large mammal resources.
Other aspects of the hominin diet, such as aquatic or vegetal resources, are assumed to be a part of hominin subsistence,
but identifying evidence of these adaptations has proved difficult.
Here we present a series of analyses that provide methodological support for the inclusion of aquatic resources in hominin dietary reconstructions.
We suggest:
bone surface modifications in aquatic spp are morphologically distinguishable from bone surface modifications on terrestrial taxa.
We relate these findings to differences that we document in the surface mechanical properties of the 2 types of bone (reflected by significant differences in bone surface micro-hardness values) between aquatic & terrestrial spp.
We hypothesize:
the characteristics of bone surface modifications on aquatic taxa inhibit the ability of zoo-archaeologists to consistently diagnose them correctly,
this influences correspondence levels between zooarchaeologists,
it may therefore result in mis-interpretation of the taphonomic history of early-Pleistocene aquatic faunal assemblages.
A blind test - using aquatic spms & a select group of 9 experienced zoo-archaeologists as participants - was designed to test this.
Investigation of 4 different possible explanations for blind test results suggest the dominant factors explaining patterning relate to
1) the specific methodologies employed to diagnose modifications on aquatic spms,
2) the relative experience of participants with modifications on aquatic bone surfaces.
We argue:
an important component of early hominin diets may have hitherto been overlooked as a result of
a) the paucity of referential frame-works within which to identify such a component,
b) the inability of applied identification methodologies to consistently do so.

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Origins of aquatic resource use in East Africa and the implications for breadth of hominin dietary versatility at 2 mya
Will Archer & David Braun

There is general agreement: hominin diet underwent dramatic changes shortly after stone-artifacts appear in the record.
It is generally assumed these changes are ass.x dietary expansion through the exploitation of large terrestrial mammal resources.
Here we present a series of analyses that suggest the absenceofaquaticresources in discussions hitherto of early-Pleistocene hominin diet may be partially attributable to prevailing zoo-archaeological methodology.
We employ a series of archaeological, ethnographic & experimental data-sets to argue: aquatic resource-use was an important component of hominin subsistence by 1.95 Ma.
We present experimental & archaeological data on (1) bone fragmentation, (2) taxonomic diversity, (3) bone surface modification, (4) skeletal element proportion, (5) size profile distributions & (6)crocodilian scavenging, to develop our argument.
We suggest: the emergence of aquatic resource-exploitation was ass.x a specific set of relative advantages vs reliance on an exclusively terrestrial resource-base:
a) a reduction in energetic investment vs economic return,
b) a decrease in the technological costs of resource acquisition,
c) a reduced level of inter-specific competition ass.x aquatic foraging opportunities + elevated probability of capitalization.
The incorporation of aquatic soft-tissues into the hominin diet at a time of the year (when other resources are depleted of fat) may have been a more important component of hominin dietary strategy than previously assumed.
This strategy would have allowed a maintained seasonally consistent source of calorie-dense foods.
The seasonal contexts within which specific aquatic spp are accessible, suggest: exploiting them may have offset fluctuations in hominin energetic intake ass.x variability in the seasonal availability of terrestrial foods.

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Early Pleistocene aquatic resource use in the Turkana Basin
Will Archer cs 2014 JHE

Evidence for the acquisition of nutritionally dense food resources by early-Pleistocene hominins has implications for hominin biology & behavior.
Aquatic fauna may have comprised a source of highly nutritious resources to hominins in the Turkana Basin at c 1.95 Ma.
Here we employ multiple data-sets to examine early-Pleistocene aquatic resource use.
We focus on 4 components of aquatic faunal assemblages (1) taxonomic diversity, (2) skeletal element proportion, (3) bone fragmentation, (4) bone surface modification.
These are used to identify associations between early-Pleistocene aquatic remains & hominin behavior at the site of FwJj20 (KoobiFora Fm, Kenya).
We focus on 2 dominant aquatic species: catfish & turtles.
We suggest:
data on aquatic resource availability & ethnographic examples of aquatic resource use complement our observations on the archaeological remains from FwJj20.
Aquatic food items provided hominins with avaluable nutritional alternative to an exclusively terrestrial resource base. We argue:
specific advantages afforded by an aquatic alternative to terrestrial resources include
1) a probable reduction in required investment of energy (vs economic return in the form of nutritionally dense food items),
2) a decrease in the technological costs of resource acquisition,
3) a reduced level of inter-specific competition ass.x carcass access & an associated reduction of predation risk vs terrestrial sources of food.
The combined evidence from FwJj20 suggests:
- aquatic re-sources may have played a substantial role in early-Pleistocene diets,
- these resources may have been overlooked in previous interpretations of hominin behavior.