Earliest archaeological evidence of persistent hominin carnivory

The emergence of lithic technology by ~2.6 million years ago (Ma) is often interpreted as a correlate of increasingly recurrent hominin acquisition and consumption of animal remains. Associated faunal evidence, however, is poorly preserved prior to ~1.8 Ma, limiting our understanding of early archaeological (Oldowan) hominin carnivory. Here, we detail three large well-preserved zooarchaeological assemblages from Kanjera South, Kenya. The assemblages date to ~2.0 Ma, pre-dating all previously published archaeofaunas of appreciable size. At Kanjera, there is clear evidence that Oldowan hominins acquired and processed numerous, relatively complete, small ungulate carcasses. Moreover, they had at least occasional access to the fleshed remains of larger, wildebeest-sized animals. The overall record of hominin activities is consistent through the stratified sequence ??? spanning hundreds to thousands of years ??? and provides the earliest archaeological evidence of sustained hominin involvement with fleshed animal remains (i.e., persistent carnivory), a foraging adaptation central to many models of hominin evolution.This research was supported by funding from the National Science Foundation, Leakey Foundation, Wenner-Gren Foundation, National Geographic Society, The Leverhulme Trust, University of California, Baylor University, and the City University of New York. Additional logistical support was provided by the Smithsonian Institution???s Human Origins Program and the Peter Buck Fund for Human Origins Research, the British Institute in Eastern Africa, and the National Museums of Kenya. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Local Alignment Refinement Using Structural Assessment

Homology modeling is the most commonly used technique to build a three-dimensional model for a protein sequence. It heavily relies on the quality of the sequence alignment between the protein to model and related proteins with a known three dimensional structure. Alignment quality can be assessed according to the physico-chemical properties of the three dimensional models it produces

Tooth-mark frequencies and long bone portion representation: results from modern experiments and excavations at KJS.

<p>Portions defined in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone-0062174-t002" target="_blank">Table 2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174.s001" target="_blank">Table S1</a>. ‘Shafts’ include both near-epiphyseal and mid-shaft specimens. Complete bones are not included in epiphysis-to-shaft calculations (number of complete bones = 2, 7, and 1; beds KS-1 through KS-3, respectively). Ellipses outline the range of results in experimental feeding scenarios involving: carnivores-only, hominins-only, or a sequence of hominins-then-carnivores (i.e., ‘hominin-first’). The dashed line is a published least-squares regression for hominin-first scenarios <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Blumenschine1" target="_blank">[22]</a>. Hominin-only scenarios have no tooth marks, hence the placement of the ellipse beneath the x-axis. KJS data from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone-0062174-t002" target="_blank">Table 2</a> are for summed body sizes. KJS epiphysis-to-shaft ratios: 0.26, 0.22, and 0.19 for beds KS-1 though KS-3 respectively. KJS tooth-mark data displayed as solid vertical bars, with bars representing the range of analysts’ results. Results from Kanjera are consistent with hominin-first contexts.</p

Skeletal element representation for (A) small and (B) medium-sized bovids, Bed KS-1.

<p>Abundance data presented as percent minimum animal units (%MAU), calculated following the literature <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Lyman1" target="_blank">[43]</a>. KJS data derived from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174.s003" target="_blank">Table S3</a>. 100% MAU = 6 for small bovids, 9 for medium-sized bovids. Similar patterns of skeletal element representation are present in Beds KS-2 and KS-3.</p

Faunal and lithic inventory.

<p>NISP (number of identified specimens) and MNI (minimum number of individuals) are defined and quantified following the literature <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Lyman1" target="_blank">[43]</a>. ‘Total NISP’ reflects the sum of specimens recovered with coordinate data and included in this study. Tens of thousands of non-identifiable bone and tooth fragments <2 cm are omitted from this study. Fossils from conglomeratic facies (CP levels) are poorly preserved <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Plummer2" target="_blank">[49]</a>, and are likewise excluded from this study: KS-2CP (n = 259), KS-3CP (n = 102). Macro-mammals are defined here as weighing >5 kg. Macro-mammal NISP values are total sums and, in parentheses, the sum of specimens identified beyond Linnean class. %NISP and %MNI include macro-mammals only. Faunal and lithic counts are from the literature <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Ferraro1" target="_blank">[17]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Braun4" target="_blank">[55]</a>.</p

Location of Kanjera along the modern shoreline of Lake Victoria, East Africa.

<p>(A) Kanjera lies to the immediate northeast of Homa Mountain, a volcanic complex active from the middle Miocene to the Pleistocene. The Winam Gulf fills the western end of the Nyanza Rift, an E-W graben with origins in the early Miocene. (B) Beds KS-1 through KS-3 of the Kanjera Formation (Southern Member) sample floodplain and low-aspect channel contexts originally deposited between the mountain and the nearby shores of a shallow lake <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Plummer2" target="_blank">[49]</a>. Satellite imagery from USGS and NASA.</p

Tooth-marked mid-shaft fragments: results from experimental assemblages and excavations at KJS.

<p>Figure follows a published model <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Lupo1" target="_blank">[26]</a>. Hominin-first assemblages refer to remains initially defleshed and demarrowed by hominins, then subsequently exposed to large-bodied carnivores (primarily hyenas). Carnivore-first assemblages refer to remains initially defleshed and/or demarrowed by large-bodied carnivores (primarily hyenas and/or lions). Data for body sizes 1–4 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Bunn1" target="_blank">[21]</a>. Modern data (with single standard deviations where available) derived from the literature <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Blumenschine2" target="_blank">[23]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Lupo1" target="_blank">[26]</a>, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Selvaggio1" target="_blank">[56]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Marean2" target="_blank">[58]</a>. KJS frequencies are from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone-0062174-t002" target="_blank">Table 2</a> and <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174.s001" target="_blank">Table S1</a>. Multiple symbols for KJS indicate the results of multiple analysts. X’s indicate minimum and maximum estimates of damage (see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174.s001" target="_blank">Table S1</a>).</p

Bone surface modifications.

<p>(A) KJS 7472, a small bovid metatarsal from KS-2 bearing cut marks; (B) KJS 7379, a medium-sized bovid humerus from KS3 bearing pair of hammerstone notches, the specimen is also cut-marked (not figured); (C) KJS 5447, a mammal limb bone shaft fragment from KS-2 with percussion pit and striae, the specimen is also cut-marked (not figured); (D) KJS 2565, a small bovid femur from KS-2 with numerous cut marks. Scale is 1 cm in panels (A-D); 1 mm in the panel (D) close-up. Specimen numbers are field designations, not KNM accession numbers.</p

Bone surface modification frequencies.

<p>Modifications detailed by long bone portion <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Blumenschine1" target="_blank">[22]</a>–<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Capaldo1" target="_blank">[24]</a>, bed, and analyst. Epiphyseal fragments (EPI) bear at least some of the proximal or distal articular surface. Mid-shaft fragments (MSH) are diaphyseal specimens that lack cancellous bone on medullary surfaces. Bone modifications follow the literature [17 and references therein], and include tooth marks (TM: pits, scores, furrows), cut marks (CM), and percussion marks (PM: pits, striae). Bone modification frequencies are listed by analyst: Ferraro, Pobiner, and Oliver (in order from left to right). Samples are bovid and taxonomically-indeterminate long bone specimens (i.e., humerus, radius, metacarpal, femur, tibia, metatarsal, or ‘long bone shaft fragment’), ≥2 cm in length, from body sizes 1–3 (i.e., small and medium-sized) <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Bunn1" target="_blank">[21]</a>, with ‘very good’ to ‘excellent’ bone surface preservation (i.e., surface conditions 4–5 <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0062174#pone.0062174-Ferraro1" target="_blank">[17]</a>) and without recent or geological fractures. Data for summed body sizes, including ‘size indet’.</p