"...the behaviour of most present day humans remains moderated by magical thinking-type mental processes (lack of integration between the left prefrontal cortical areas and memory), underwritten by sub-optimal cause and effect perception."
Robert G. Bednarik, An aetiology of hominin behaviour, Homo, 2012
Thursday, 10 December 2015
Monday, 7 December 2015
Tuesday, 3 November 2015
Wednesday, 1 July 2015
Tuesday, 23 June 2015
Thursday, 11 June 2015
Sunday, 10 May 2015
Wednesday, 15 April 2015
In fact, the prominence of the chin in present day humans is well documented and understood.
"Compared to chimpanzees and macaques, human skulls exhibit a derived spatial distribution of growth fields, especially in the face (Enlow, 1990). While the internal (basicranial) surface of the maxilla grows via interosseous bone deposition (sutural bone growth), the external (facial) surface of the maxilla as well as the external symphyseal area of the mandible exhibit resporptive fields. As an effect, the human face grows inferiorly and anteriorly through maxillobasiocranial bone apposition, but forward growth is counteracted by maxillofacial resportive growth fields. The combination of these processes results in a retracted, vertically oriented face in which the chin represents the most prominent (i.e., least resorbed) part."
Zollikofer C., 2012, Evolution of hominin cranial ontogeny, Progress in Brain Research, 195: 273-289.
Clearly the chin is a neotenous feature but Robert Franciscus from the University of Iowa proposes that it is evidence of so-called "modern humans" replacing "Neanderthals" around 60,000 years ago. Past horizons (http://www.pasthorizonspr.com/index.php/archives/04/2015/our-chins-developed-when-we-started-to-build-social-networks) quote him saying:
"What we’re arguing is that modern humans had an advantage at some point to have a well-connected social network, they can exchange information, and mates, more readily, there’s innovation and for that to happen, males have to tolerate each other. There had to be more curiosity and inquisitiveness than aggression, and the evidence of that lies in facial architecture.”
So in a desperate bid to support the contention that "modern humans" outcompeted or absorbed Neanderthals Franciscus turns incredibly to face architecture. Whilst it is probably correct to imply that the transition from the robust hominins of the past to the gracile hominins of the present day may be in part explained by changing hormone levels (as a result of increasingly culturally mediated mating behaviour for neotenous features) there is no evidence to support the contention that the chin is a feature found only in populations exiting Africa, or indeed that there were well connected social networks exclusive to these groups.
"...this research, demonstrating overlap in overall anterior symphyseal shape between H. sapiens and Neandertals, raises questions about the distinctiveness of the human chin."
As noted on numerous occasions on this blog there is no evidence of a "replacement" of Neanderthals in Europe by "modern humans" let alone evidence for the "well connected social networks" that Franciscus refers to. Past Horizons have confused matters further by referring to work that does not support an evidence base for morphological distinction between so called species but rather underlines the key learning: extant autapomorphies are a result of pedomorphosis through neoteny, a heterochronic process.
Friday, 27 March 2015
Friday, 6 March 2015
Friday, 27 February 2015
Monday, 23 February 2015
Consider this for a moment. The mostly Oxford based researchers contend that analysis of stone tools can yield information relating to biological or cultural dispersion.
Even if the authors of the paper were able to reliably identify the culture or "species" of human responsible from a given assemblage of stone tools, any analysis concerning the distribution or "pattern of dispersal" would relate only to preservation conditions and chance detection. The idea that a species could be tracked by simply referring to a set of etically described stones is critically flawed and therefore the results are untestable and unscientific.
Any (subjectively) perceived similarities between so called East African lithic assemblages and those from elsewhere is moot in the face of the continuity of in-situ technological development evident from the Middle Palaeolithic into the Upper Palaeolithic at sites throughout Europe.
The assertion that "Most researchers accept that Homo Sapiens evolved in Africa during the late Middle Pleistocene" is argumentum ad populum and ignores the mounting genetic, fossil, stone tool and cultural evidence which refutes it.
Friday, 20 February 2015
Saturday, 7 February 2015
Published recently by the authors (Holliday, Gautney and Friedl) and Jean-Jaques Hublin (one of the commentators) on Academia.edu is Right for the Wrong Reasons: Reflections on Modern Human Origins in the Post-Neanderthal, 2014, Current Anthropology: 55(6), pp. 696-724.
"We argue this because we reject one of the major tenets of MRE: global gene flow that prevents cladogenesis from occurring. First, using reconstructions of Pleistocene hominin census size, we maintain that populations were neither large nor dense enough to result in such high levels of gene flow across the Old World."All scenarios suggested for population sizes are at best untestable and at worse entirely fictitious (Bednarik 2013). The failure of many Pleistocene archaeologists to comprehend the implications of taphonomic logic are readily illustrated by the tendency to base these population estimates on the archaeological record. Of course this record is not a record of human population sizes and/or distribution but rather is representative of where the best preservation conditions occur and where researchers have looked. For instance, some estimates assume that there were large unpopulated regions. However, as Bednarik (2013) suggests, a sensible null hypothesis would be to assume that by 45,000 years ago all environments of four continents were as densely occupied as their carrying capacities allowed for. In other words, that there was a contiguous population from Africa to Asia. In such a scenario, following thousands of years of regionalisation reticulate introgression, genetic drift and episodic genetic isolation may all have occurred as suggested by Franz Weidenreich's in 1946. Note that the multiregional model of polycentric human evolution has diagonal lines (Figure 1) which accommodate these conditions.
The Assimilation theory (AM) concedes the occurrence of genetic exchange between so-called "Neanderthals" and "Modern Humans", i.e. it accepts that they are conspecific - able to produce fertile offspring (Bednarik 2011). AM merely claims an in-flow of African genes. All models of reticular gene flow are in fundamental agreement with the original "trellis" diagram of Weidenreich and AM is no exception however positioned. Wrong isn't right.