Wednesday, July 19, 2017

The Cerutti Mastodon Site: Archaeological or Paleontological?

Eric Boëda, Christophe Griggo & Christelle Lahaye
Paleoamerica
Published online: 22 Jun 2017
(Link) pdf available at research gate

from the paper:

Once we have examined the appropriateness of the anthropogenic nature of the artifacts and the fact that we are confronted with a place of fracturing activity, it is obviously necessary to examine the chronological data which are crucial because they suggest that Cerutti is the oldest known site in the Americas. For this purpose, the lead author sought the advice of a specialist in the methods used (optically stimulated luminescence (OSL) and uranium-thorium (U-Th) dating), coauthor Lahaye. Indeed, without collagen the radiocarbon dates were immediately excluded from the methodological pool of dating. Instead, both dating methods used in this work converged on Pleistocene ages of the site. Quartz grains studied with OSL were too close to or beyond the limit of the method, so that only minimum ages could be deduced. They show the sediment surrounding the fossils of the Cerutti Mastodon site were not exposed to natural light for at least 60–70 ka. It can be deduced, if all the depositional and post-depositional phenomena are well understood, that the fossils enclosed in the site’s sediments are older than 60–70 ka. U-Th measurements on bones also can only be considered as minimum ages of bones’ burial. The results of analyses of different bones are consistent, giving an age of ca. 130.7 ± 9.4 ka. Combining OSL and U-Th results, in a well understood stratigraphic context, leads to the conclusion that the Cerutti mastodon dates to around 130 ka.

The resolution of the methods used does not allow a very precise chronological result (130.7 ± 9.4 ka), thus situating the site at the interface between the end of  the latest glacial (MIS 6), which is interpreted to have been a cold phase like the last glacial maximum and the beginning of the rapid warming which marked the beginning of the latest interglacial (MIS 5e). This chronological position makes it difficult to discuss the origins of this group of individuals and the process of their dispersal. For, assuming that they were newcomers, depending on the date taken into account, on the one hand they could have existed at the maximum extent of the glaciers blocking the land passage between Alaska and the Great Plains of North America, with the lowering of sea level more than 100 meters and the creation of a land bridge between Asia and North America. On the other hand, the alternative situation would have been characterized by a rise in sea level, which may have led to the closing of the land bridge but at the same time the opening of a corridor after the disappearance of glaciers, with the formation of large lakes as consequences. So, when in time are we situated, exactly? The fauna is not sufficiently informative to make us lean to one alternative or the other. Nonetheless, the coastal seaway remained a permanent solution whatever the climates.

Perhaps, however, these were not newcomers but instead descendants of generations already present in the Americas. But let us guard ourselves during this time of scientific upheaval to give priority to just those facts which alone have heuristic value. All the scenarios that we envisage must remain heuristic scenarios and not a paradigm, as we had with “Clovis first”.  Keep in mind that the facts once verified remain paramount.  We experienced this ourselves in Piauí in South America, where our successive and repeated discoveries in the same geographical area testified not to the presence of a “Robinson Crusoe” but to a large perennial population that existed for at least 5000 years between 35 and 40 ka (Boëda et al. 2016). This means that scientific research, finally rid of traditional ideological locks, can focus on the expansion of prospecting, taking into account the geomorphological changes of the Pleistocene. We have to look for the sites, in the places where they are likely to be, under water or under many meters of sediment.

We are left finally with one last problem: the creators of the Cerutti feature. Holen et al. (2017) provide a realistic picture of the situation in Asia. We have a fairly broad choice of candidates – late Homo erectus, Neanderthal, archaic Homo sapiens, or even Denisovan. In the absence of hominin remains, some researchers will consider these candidates’ respective cognitive aspects when making a taxonomic attribution. For our part, having experience across Asia from north to south, we would be suspicious of any specific biological/cultural fit. We are dealing with technical worlds quite different from our Western and African references. From experience, let us guard against prejudice and remain open to all possibilities.

To conclude, I endorse the last sentence of Holen et al.’s (2017) article by extending it to all of America:  this discovery calls for further archaeological investigation of the North and South American strata of early-late Pleistocene age.

Saturday, July 15, 2017

An updated age for the Xujiayao hominin from the Nihewan Basin, North China: Implications for Middle Pleistocene human evolution in East Asia

Hong Ao, Chun-Ru Lui, Andrew P. Roberts, Peng Zhang, Xinwen Xu
Journal of Human Evolution
Volume 106, May 2017, Pages 54-65
(Link) open access

from the paper:

Implications for hominin evolution

The Xujiayao Homo fossils have mixed characteristics associated with European Neanderthals, Asian H. erectus, and modern H. sapiens (Jia and Wei, 1976; Jia et al., 1979; Wu, 1980; Bae, 2010; Wu et al., 2013, 2014; Wu and Trinkaus, 2014; Xing et al., 2015), which makes it difficult to affiliate the Xujiayao hominins to “classic” H. erectus, modern humans, or Neanderthals. Thus, the Xujiayao hominins were assigned to archaic H. sapiens (Jia and Wei, 1976; Jia et al., 1979; Wu, 1980; Wu and Poirier, 1995), although this unique term in China is controversial as noted by later studies (e.g., Rightmire, 1998; Dennell and Petraglia, 2012). Our updated chronology makes the Xujiayao Homo fossils among the oldest archaic H. sapiens in China. They are contemporaneous with the earliest archaic H. sapiens remains in eastern China from Chaoxian (310–360 ka; Shen et al., 2010). Combining the archaic H. sapiens remains from New Cave (248–269 ka; Shen et al., 2004a) at Zhoukoudian, Dali (∼270 ka; Xiao et al., 2002) and Jinniushan (∼260 ka; Rosenberg et al., 2006), it appears that archaic H. sapiens occupied a vast area across China during the mid-Pleistocene. Unlike some African mid-Pleistocene Homo individuals that were associated with Acheulian stone tools (Rightmire, 2008), the archaic H. sapiens from Xujiayao and other East Asian sites (e.g., Jinjiushan and New Cave) were associated with a relatively simple Oldowan-like technology (Bae, 2010; cf. Fig. 4). Despite having a simple technology, the Xujiayao hominins were able to successfully obtain regular sources of animal fat and protein that probably helped them to survive harsh mid-latitude northeast Asian winters. Surface modifications on long bone midshafts indicate that the Xujiayao hominins were skilled large mammal (e.g., horse) hunters and had access to high utility (meat-bearing, marrow-rich) long bones (Norton and Gao, 2008), which was important for overwintering in the >40°N temperate zone.

Homo erectus occupation of East Asia started at 1.7–1.6 Ma and persisted to ∼400 ka as suggested by fossils from Yuanmou Basin (∼1.7 Ma; Zhu et al., 2008), Nanjing (580–620 ka; Zhao et al., 2001), Hexian (400–420 ka; Grün et al., 1998), and Yunxian (0.936 Ma; Dennell, 2015) in South China and Gongwangling (1.62–1.63 Ma; Zhu et al., 2015), Chenjiawo (0.65 Ma; An and Ho, 1989), and Zhoukoudian (0.4–0.77 Ma; Shen et al., 2001, 2009) in North China (Fig. 10). In Africa, H. erectus was giving way to Homo heidelbergensis during the terminal Early Pleistocene to the earliest mid-Pleistocene (ca 600–800 ka; Rightmire, 1998, 2008, 2009, 2013). Until now, Homo fossils with unambiguous affinities to H. heidelbergensis have not been reported from East Asia (Bae, 2010), although some divergences of Yunxian crania from the standard H. erectus pattern imply links to H. heidelbergensis (Rightmire, 1998; Stringer, 2002). Whether H. heidelbergensis dispersed to East Asia remains enigmatic. Further in-depth study of Homo fossils and more material are needed to assess the history of H. heidelbergensis in Asia. However, persistence of H. erectus in East Asia to at least 400 ka, when H. heidelbergensis was giving way to Homo neanderthalensis in Europe (Rightmire, 1998), does not support the replacement of H. erectus by H. heidelbergensis in East Asia (Groves and Lahr, 1994; Etler, 2004). Coexistence of H. heidelbergensis and H. erectus is possible if the presence of early mid-Pleistocene H. heidelbergensis is documented in East Asia. Based on more precise recent ages for various Homo fossils established in recent years and without regard to previous imprecise ages that were underestimated by U-series dating of bones, it is possible that archaic H. sapiens (370–250 ka) may have not interacted with the older H. erectus (1700–400 ka) or younger modern H. sapiens (<150 ka) in East Asia, as indicated by our updated Chinese Homo chronostratigraphy in Figure 10.

Thursday, July 6, 2017

Paleoart of the Lower Paleolithic

Robert Bednarik
(Link) open access pdf

from the paper:

Introduction

The subject of this paper, the very earliest forms of art-like products created by hominins, is of fundamental importance to both the Arts and the Humanities. In the sciences it is essential to cast propositions in cause and effect formats: while a disease is defined by its symptoms, it should rightly be expressed as a function of its etiology. What we define as Arts and Humanities are entirely self-referential and anthropocentric pursuits and it is useful to occasionally place them into the greater epistemological context of reality: how things might really be in the world. Protagoras’ dictum that man is the measure of everything explains the Humanities and leaves the Sciences with a quandary. But pursuing cause and effect issues has proved fairly successful over the centuries, and it might be useful in examining where the Arts and the Humanities originate. As a species we have, despite our ingenuity, so far failed to explain how the contents of our crania form concepts of the world from the sensory input reaching them, and an explanation of how we manage to develop constructs of reality has largely eluded us thus far. In part this may be attributable to our inability to recognize the role of exograms, the externalized memory traces constituting the thing we call culture (Bednarik 2014), in the way we connect with external reality. It might then be useful to investigate how the human ability of creating exograms, which is one of the few human faculties not shared with other animals (others being metarepresentation, recursion, and autonoetic consciousness), came into existence.

This is not an easy task and has never been attempted by the gatekeepers of the human past, Pleistocene archaeologists and paleoanthropologists, who are more concerned with the tools and skeletal architecture of our ancestors. Indeed, very few authors have even concerned themselves with the phenomenon of exograms so far (Bednarik 1987; Donald 1991), and the exograms of the human past have either been ignored or explained away as "art" or "symbols" by archaeologists. There is no evidence that they were either. Just as the humanistic definitions of culture and civilization lack scientific significance and relevance, humanistic comprehension of art and symbols is impaired by simplistic understanding of what these concepts embody. Paleoart (a generic term defining art-like productions preceding written records) was not necessarily "art," in the sense of that term today (Davies 1991; Stecker 1997; Carroll 2000); nor can we know if it was symbolic (involving referent and referrer). The term "art" always derives from an ethnocentric concept: "the status of an artifact as a work of art results from the ideas a culture applies to it, rather than its inherent physical or perceptible qualities. Cultural interpretation (an art theory of some kind) is therefore constitutive of an object’s arthood" (Danto 1988). It would be preposterous to contend that modern (Westernized) humans could fathom the ideas past cultures applied to paleoart tens or hundreds of millennia ago. They cannot even establish the status of recent ethnographic works (Dutton 1993) with any objective understanding: interpretation is inseparable from the art work (Danto 1986: 45; Convey 2014). To regard paleoart as art is therefore an application of an etic and ethnocentric idea to products of societies about whose emic parameters nothing is known in most cases ("emic" refers to knowledge and interpretation within a culture, "etic" refers to interpretation by another culture).


Here it will be attempted to define what is currently known about the earliest surviving exograms, which are collectively defined as "paleoart". Palaeoart of the Lower Paleolithic period seems to have been found for well over 150 years but it has remained largely ignored, misinterpreted, or its existence was fundamentally denied. Most archaeologists and paleoanthropologists of recent decades attempt to refute anthropogenically modified objects located in Lower and Middle Paleolithic contexts as being taphonomic accidents or "natural" in origin. Their presumption is that all Lower and Middle Paleolithic humans (including Homo habilis, H. rudolfensis, H. ergaster, H. georgicus, H. erectus, H. heidelbergensis, and H. sapiens neanderthalensis ) were cognitively incapable of expressing themselves through "art" or exograms. They "know" these hominins were cognitively incapable of expression because they were not modern humans; they have been convicted of mental deficiency by negative evidence (Speth 2004). This is despite the clear evidence that these hominins have engaged in maritime colonization since approximately a million years ago, and have crossed sea barriers of up to 180 km to reach over twenty islands and one continent prior to having "Upper Paleolithic" technology (Bednarik 1999).

How did such biased perceptions develop historically? They begin with the (still present among many archaeologists) assumption that de Mortillet’s divisions of European Paleolithic stone tools into the Lower, Middle, and Upper "stages" correspond to biological grades of Lower, Middle, and Upper Paleolithic European humans (Monnier 2006). Next came Marcelin Boule’s classification of all Neanderthals as deficient degenerates on the basis of his analysis of the geriatric male from La Chappelle-aux-Saints. It is still common in the media and pop-culture for Boule’s caricature to be regarded as valid. Then came the "New Archaeology" of Lewis Binford, who with his students wanted to practice a new, explicitly "scientific", archaeology, mainly through a process of accusing other archaeologists of subjectivity and imprecision. Such accusations were accompanied by criticisms of earlier interpretations of the archaeological record, especially regarding European Neanderthal sites. Then we experienced the famous Wolpoff-Stringer debate, which was followed by the Krings et al. (1997) paper on the Neanderthal DNA, after which many people discounted any similarities between Neanderthals and anatomically modern humans. The success of the marketing campaign promoting the replacement ("African Eve") hypothesis (Thompson 2014) began to wane only with the erosion of its credibility (Bednarik 2008a) in recent years. Denying archaic humans cognitive abilities of any consequence has become a fossilized "unstable orthodoxy" in archaeological reasoning (Thompson 2014), but one that is squarely refuted by the data reviewed here.

This paper summarizes the currently available credible evidence of "symbolic" or non-utilitarian behavior from the Lower Paleolithic, the earliest period of human tool making (beginning at least 3 million years ago and ending very roughly 200,000 years ago). Material evidence of this kind is defined as "palaeoart;" whether or not this constitutes art in the modern accepted usage of that term is irrelevant. The primary issue is that this material is crucial in considering the cognitive and intellectual status of the period’s hominins. For purely descriptive purposes the relevant evidence can readily be divided into a few groups: small perforated objects that may have been used as beads or pendants, petroglyphs, indications of pigment use, proto-figurines, engravings on portable objects, and unmodified objects that are thought to have been carried around because of some outstanding property (manuports).

Palaeoart finds of this earliest time of exogram use are still exceedingly rare, and among those reported some are of doubtful status or have fairly been rejected. The evidence presented here has been culled from a much greater corpus of reported finds. It consists of specimens that constitute either convincing evidence of symbolism, or that provide such compelling aspects that they deserve to be seriously considered in this context. I have examined most of the crucial specimens myself and their listing here indicates that I accept their authenticity after careful analysis. In the cases where reasonable reservations are appropriate I will try to present these fairly.

(read more)

Monday, July 3, 2017

Evidence of Hominin Use and Maintenance of Fire at Zhoukoudian

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Tuesday, June 27, 2017

Use of red ochre by early Neandertals

Wil Roebroeks, Mark J. Siera, Trine Kellberg Nielsena, Dimitri De Loecker, Josep Maria Parés, Charles E. S. Arps, and Herman J. Müchere
PNAS
July 27th, 2011
(Link) open access

Abstract

The use of manganese and iron oxides by late Neandertals is well documented in Europe, especially for the period 60–40 kya. Such finds often have been interpreted as pigments even though their exact function is largely unknown. Here we report significantly older iron oxide finds that constitute the earliest documented use of red ochre by Neandertals. These finds were small concentrates of red material retrieved during excavations at Maastricht-Belvédère, The Netherlands. The excavations exposed a series of well-preserved flint artifact (and occasionally bone) scatters, formed in a river valley setting during a late Middle Pleistocene full interglacial period. Samples of the reddish material were submitted to various forms of analyses to study their physical properties.  All analyses identified the red material as hematite. This is a nonlocal material that was imported to the site, possibly over dozens of kilometers. Identification of the Maastricht-Belvédère finds as hematite pushes the use of red ochre by (early) Neandertals back in time significantly, to minimally 200–250 kya (i.e., to the same time range as the early ochre use in the African record).

Friday, June 23, 2017

Early evidence of stone tool use in bone working activities at Qesem Cave, Israel

Andrea Zupancich, Stella Nunziante-Cesaro, Ruth Blasco, Jordi Rosell, Emanuela Cristiani, Flavia Venditti, Cristina Lemorini, Ran Barkai & Avi Gopher
Scientific Reports 6,
Article number: 37686
25 November 2016
(Link) open access

Abstract

For a long while, the controversy surrounding several bone tools coming from pre-Upper Palaeolithic contexts favoured the view of Homo sapiens as the only species of the genus Homo capable of modifying animal bones into specialised tools. However, evidence such as South African Early Stone Age modified bones, European Lower Palaeolithic flaked bone tools, along with Middle and Late Pleistocene bone retouchers, led to a re-evaluation of the conception of Homo sapiens as the exclusive manufacturer of specialised bone tools. The evidence presented herein include use wear and bone residues identified on two flint scrapers as well as a sawing mark on a fallow deer tibia, not associated with butchering activities. Dated to more than 300 kya, the evidence here presented is among the earliest related to tool-assisted bone working intended for non-dietary purposes, and contributes to the debate over the recognition of bone working as a much older behaviour than previously thought. The results of this study come from the application of a combined methodological approach, comprising use wear analysis, residue analysis, and taphonomy. This approach allowed for the retrieval of both direct and indirect evidence of tool-assisted bone working, at the Lower Palaeolithic site of Qesem Cave (Israel).

Tuesday, June 20, 2017

Pleistocene Palaeoart of Africa

Robert G. Bednarik
Arts 2013, 2, 6-34
8 February 2013
(Link)

 From the paper:


"The Tan-Tan proto-sculpture from the fluvial terrace deposit on the north bank of the River Draa in southern Morocco is from a rich assemblage of middle Acheulian lithics, which in this region are in the order of between 300 and 500 ka old. The quartzite object is of natural form, but has been modified. Five of symmetrically located eight grooves that emphasize its human form were made by careful impact, and traces of haematite suggest that it was once coated in red colour (Bednarik 2001, 2003b) [45, 50]."

Monday, June 19, 2017

Early Evidence for Brilliant Ritualized Display: Specularite Use in the Northern Cape (South Africa) between ∼500 and ∼300 Ka

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Saturday, June 17, 2017

A note on the meaning of "linear" in this blog's title

This blog is borne out of my desire to understand human origins from a technical, science based perspective.  I focus primarily on the last million years of hominin existence.  
 
Regarding the title of this blog linearpopulationmodel [linear population model], linear does not imply or connote that this blog favors a first order linear straight line progression for human evolution.  On the contrary, my impression is that human evolution is a geography distributed, dynamic, climate driven process and should be modeled as a weakly to strongly higher order linear complex system over time and geography.
 
In terms of dynamic higher order linear system modeling that has shown promise for the understanding of human evolution, I've been particular encouraged by the work of researchers such as Richard Durban and Stephen Schiffels [1], Joshua Paul, Matthias Steinrücken and Yun S. Song [2][3], and Jeff Wall [4].
 
Thanks for entertaining my clarification on this point!

Sunday, June 11, 2017

Recalibrating Archaic Admixture in Homo sapiens

I was looking at the data in the just published Hublin et al. paper, and the paper published by Rightmire back in January.  I realized that the reason that archaic admixture in H. sapiens is estimated as being low (less than 4%) is that the recent Neandertal and Denisovan samples used by Svante Pääbo's and David Reich's research groups are ill chosen in terms of the time periods they look at.  This only shows that H. sapiens, who had diverged genetically from Neanderthals and Denisovans 400,000 and 600,000 years before present, approximately, was sufficiently diverged that admixture was a low probability event.  The Neanderthal and Denisovan samples used to test admixture are less than 100,000 years old.   They are not 600,000-200,000 years old, and cannot tell us about the gradual divergence, or not, of hominins in Africa and Eurasia.

Here's an incomplete list of hominin crania:



The relationship is not well established, but it is increasingly apparent that an immediate ancestor of H. sapiens is H. heidelbergensis.  The range of H. heidelbergensis stretched from Germany to Ethiopia between 600,000 and 400,000 years ago.  This is based on the small number of H. heidelbergensis samples that exist for that period:  the Mauer Mandible, Petralona, Arago 21, and Bodo.  The range of H. heidelbergensis seems to shift further southward into Africa after 400,000 years ago, but that is difficult to assert when there are so few samples, and these are not securely dated.

What is clear is that archaic H. sapiens appears between 300,000 and 200,000 years ago in Africa, and probably derives mostly from H. heidelbergensis in Africa. What is very much not clear is the degree to which H. sapiens derives ancestry from Neanderthals, Denisovans, H. heidelbergensis, and H. erectus outside Africa in the period between 300,000 and 100,000 years ago.  We have no autosomal ancient DNA samples for Neanderthals, Denisovans, H. heidelbergensis and H. erectus from this period. 

Scientists who make these bold assertions about limited archaic admixture should qualify that their samples are very late in terms of the time that a high degree of admixture between H. sapiens and other humans would have been occurring.   I think this is especially true when talking about Asia, where it is somewhat apparent from the Dali, Jinnuishan, and Xuchang crania, that early archaic H. sapiens probably had a much broader range than Africa after 300,000 years ago.

It is frequently asserted, based on the distribution and characteristics of contemporary human DNA, that most humans left Africa no earlier than 80,000 years ago, and those that did went extinct.  There is no basis for these statements based on the admixture outside Africa argument.  The Denisovan and Neandertal samples used to make this assertion are too late and too sparse to test archaic admixture outside Africa.  These tests assume low mobility and little intermixing between African and Non-African groups between 400,000 and 80,000 years ago.  I doubt that is the case.

The process of the early formation of H. sapiens is probably much more complex than we've imagined.