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Palaeo Updates: Call for Palaeoanthropologists to Study Rising Star Hominin Remains and Start of John Hawks Human Evolution MOOC

22 Jan

Another quick post here but one that highlights a project that is pretty impressive in its implications for palaeoanthropology.  Also noted here is the start of a MOOC (Massively open online course) on human evolution that may interest the readers of this blog.

The Rising Star Expedition in South Africa has uncovered around 1200 skeletal elements from around 12 individual hominins in the first season of excavation, an unparalleled find in the excavation of palaeoanthropological sites.  Now the project is advertising openly for early career scientists to examine and describe the skeletal remains found in the cave (my favourite quote: “Palaeoheaven has arrived, it’s just solid fossils”).  This is a unique opportunity in the field of paelaeoanthropology.  Typically fossil hominin sites are kept secret with only a lucky few allowed access to prepare, study and describe the fossils once they have been carefully excavated on site and taken to a palaeo laboratory to be looked at in more detail.  This is usually a process that can take years of careful work by a small team.

But the Rising Star Expedition has been different from the very beginning, with key members of the team tweeting and blogging every incredible scene of the South African cave site and openly advertising for participants.  Now the team have advertised for early career scientists to apply for the chance to study the hominin fossils.  As stated on John Hawks blog entry on the advertisement, the Rising Star team want to recruit a large group of scientists to come together for a five-week long workshop in May/June of this year to study the remains and produce the first high quality and high impact research papers on this batch of fossil hominins.

Here is Rising Star director Lee Berger’s open invitation to study the hominin remains gathered from the Rising Star Expedition project in South Africa:

risingstarr2014

The announcement by Lee Berger, professor at the university of the Witwatersrand in South Africa and describer of Australopithecus sediba, found at the Malapa site.

Graduate students who have finished their data collection, and have the support of their supervisors, will also be considered for the opportunity.  As John Hawks states in his blog post the applicant for the workshop should be very clear in stating their experience and the datasets that they can bring to the project, be clear about your own skills, knowledge and value and do not be afraid to apply.  This is a fantastic opportunity to be involved in the study of human evolution, at the very cutting edge of the research.  I wish all the applicants the best of luck and I look forward to the dissemination of the research itself.

In other news today marks the beginning of the 8 week free MOOC course on Human Evolution: Past and Future produced by the aforementioned palaeoanthropologist John Hawks.  The MOOC, provided by Coursera, takes a in-depth look at human evolution detailing not just the complexity of the fossil record but also of the genetic record.  The course includes all the exciting news from the Rising Star Expedition and exciting footage and interviews with palaeoanthropologists at sites from around the world (including the Dmanisi site in Georgia, Malapa in South Africa and others).

I am particularly looking forward to the discussion of human evolution within the past 10,000 years and the stunning advancements made with extracting ancient DNA from fossil hominins.  I joined this course a few months ago when I first mentioned the course on this blog but you can still join up now.  Just remember that the course is split up into weekly topics so you may not want to miss one.  I have so far watched the majority of the interesting and well presented videos for the first week, the focus of which is our place among the primates.  I cannot wait to join in and participate in the course fully, hope to see you there!

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Lee Berger Talks About Rising Star Project

11 Dec

Palaoeanthropologist Lee Berger, describer of Australopithecus sediba and professor at the University of the Witwatersrand in Johannesburg, can be heard here describing the recent Rising Star Expedition and the projects rescue of hominin bones from deep inside a cave in South Africa after a chance discovery by some cavers.

The project, with support from the National Geographic and the Speleological Exploration Club of South Africa, have recently recovered around 1200 individual fossil hominin elements during a three week recovery dig at the site.  As Berger discusses in the phenomenally exciting radio interview with National Geographic it his belief that there are articulated hominin remains yet to be uncovered and rescued from the cave site.  It truly promises to be an amazing site due to the massive haul of fossil material found within a concentration no bigger then many dining room tables.  Once the fossils have been analysed scientifically further information will be released, although the project is fairly unique in the fact that it is running as an open science project.  The National Geographic (and others including John Hawks and Lee Berger) has so far done an excellent job in documenting the project (see here).

In perhaps one of the most interesting periods ever for palaeoanthropological news the interview competes with the recent investigation of the five Homo erectus individuals at the Dmanisi site in Georgia and last week’s announcement of the sequencing of mtDNA from a 300,000 year old hominin from the Sima de los Huesos site in Spain (Meyer et al. 2013).  I hope to further explore the 300,000 year old mtDNA article in detail in an upcoming entry.

As ever, I heavily recommend heading over to John Hawks weblog as his posts on the Rising Star Expedition and human evolution continue to enthrall and shed light on the fossils and genetic investigations that he is so often a part of.  We are living in some truly fascinating times where we are really starting to learn about human evolution through the glorious combination of genetic analysis and the smart approaches to extracting ancient DNA, combined with the truly amazing fossil finds of the past decade and a bit.

Bibliography

Meyer, M., Fu, Q, Aximu-Petri, A., Glocke, I., Nickel, B., Arsuaga, J-L., Martínez, I., Gracia, A., Bermúdez de Castro, J .M., Carbonell, E & Pääbo, S. 2013. A Mitochondrial Genome Sequence of a Hominin from Sima de los Huesos. Nature. 505: 403-406.

Anatomically Modern Humans: A Brief Introduction

22 Apr

The imperative of  the human species to ‘Know Thyself‘ has developed into a rapidly expanding field in palaeoanthropology.  The exploration of our species, Homo sapiens, is a particularly active field which utilizes multi-disciplinary approaches to untangle the evolutionary threads of our beginning.  The following essay introduces concepts and approaches used in this field, whilst raising current research issues.

——~…~——

“For a species that is both narcissistic and inquisitive, Homo sapiens has so far done a remarkably poor job of defining itself as a morphological entity”, Tattersall and Schwartz (2008: 49).

Thus starts the opening sentence to Tattersall and Schwartz’s 2008 article on the problems of clarifying the morphological distinctiveness of anatomically modern humans (AMH or the species Homo sapiens).  It is perhaps applicable not just to the morphological characteristics but also the fossil record and origins of AMH themselves (Pearson 2008: 38).  This paper, then, will discuss the principles behind the definitions and evolution of AMH in context with reference to its behaviour and morphological traits.  In turn, the dominant models of the origin and subsequent dispersion of AMH will be discussed, with reference to where Homo sapiens ‘fit’ in the palaeoanthropological record.  A wealth of new genetic research data and fossil finds has considerably opened up the treasure chest of hominin information, which is having a considerable impact on our understanding of the H. sapiens place in the evolutionary records (Bowden et al. 2012, Curnoe et al. 2012, Krause et al. 2010, Prat et al. 2011, Wood 2005: 42).  It is directly as a result of how the reporting of evolutionary science has changed in the past few decades (McEwan 2012), and how technological approaches have uncovered so much genetic data in reconstructing fossil record relationships (Jurmain et al. 2011: 270), that the definition of AMH is not so easy.  This paper will conclude with a talk on how the biocultural evolution of H. sapiens is now impacting both our environment and localised populations in certain contexts (Le Fanu 2009, Hawks et al. 2007, Jurmain et al. 2011).

It is important to note that H. sapiens are the last species of the genus Homo, with the first species tentatively dated in Africa to nearly 2.5 million YA (years ago), which led to the first dispersal of hominins (largely H. erectus) from Africa around 1.8 YA (Jurmain et a.l 2011: 240); AMH dispersal occurred much later.  It was once thought that AMH were defined by modern anatomy and behaviour at the junction of the Upper Palaeolithic around 40,000 YA (Nowell 2010: 438), however, recent palaeoanthropological finds and research have discovered a distinct ‘decoupling’ between early AMH anatomy and later symbolic/modern behaviour, with anatomically similar traits of AMH in fossils pinpointed to east and south Africa to around 200,000 YA (Rightmire 2008: 8, Wood 2005).  However there are problems concurrent with the dating of the hominin fossil record, as Millard (2008: 870) concludes that ‘the dating evidence for many key fossils is poor’.  Typically there are a number of assigned morphological features that mark out Homo sapiens compared to other species in the Homo genus (Table 1).  As Tattersall and Schwartz (2008: 51) note, however impressive the suite of features ‘not all of them are expressed with equal emphasis in all living humans’.  When this is combined with the fossil record of AMH, with individuals often taken as examples for their own long lost skeletal population and the problems inherent in the preservation of skeletal elements (geological pressure, scavenging etc), we should rightly be wary of definitively assigning a species name before comparison with relative contextual remains, stratigraphic layers and other similar period sites (Millard 2008, Pettitt 2005).

General Characteristic Morphological features of AMH:

Cranial:

  • Cranial capacity in excess 1350cc (variable).
  • Distinct chin (inverted T).
  • Relatively veretical frontal bone
  • Relatvely flat non-projecting face.
  • Brow ridge expressed more clearly in males.
  • Round occipital region.
  • Small incisor teeth.

Post Cranial:

  • Narrow thorax.
  • Small and narrow pelvis.
  • Straight limb bones.
  • Typically less ‘robust’, more gracile, then recent ancestors.

Table 1. General morphology for Homo sapiens (Pettitt 2005: 132, Tattersall and Schwartz 2008: 51, Wood 2005: 110). NB see also Pearson’s Table 2 (2008: 39).

Using a cladistics framework, Pearson (2008: 38) highlighted the fact that there are specific difficulties in using statistical measurements of metrical and discrete measurements as having been conceptualised as derived features in AMH crania, with comparison to Neandertal and H. erectus crania.  However there are further problems when trying to establish if the earliest H. sapiens African fossils of Omo Kibish, the Herto crania, or Near Eastern Skhul and Qafzeh fossils fit within the 95% rate of modern features, with results not even reaching the 75% fit of the modern features for AMH (Pearson 2008: 39).  In part this is due to fossils, such as the Herto crania, which are used as the mean of that particular population, which ultimately ‘conflates individual, within-population variation and between-population variation’ (Jurmain et al. 2011, Pearson 2008: 39).  Other problems of quantifying such long chronological morphological differences include the lack of various populations of modern (Australian aboriginals, for example) and certain prehistoric peoples being outside of the 95% confidence to fit the given morphological concept of AMH.  Clearly there needs to be a control on the temporal/geographic population of the AMH under consideration in such studies, when carrying out both the statistical analysis with other fossil hominins and when taking the defining measurements.

Pettitt (2005: 132-137) argues that H. sapiens should be classed into three arbitrary chronological groups of morphological continuity: 1) those of the earliest H. Sapiens, including material from Bodo (Ethopia), Broken Hill (Zambia) and Elandfontein (South Africa) amongst others; 2) Transitional (or archaic) H. sapiens including Herto, Omo Kibish 1 and 2 (Ethiopia), Florisbad (South Africa) and Jebel Irhoud (Morocco); 3) finally AMH including Makapansgat, Border Cave and Equus Cave (South Africa), Taramsa (Egypt), and Dar-es-Soltan (Morocco) examples (see Table 2 below for dates).  This ordering of morphological continuity defines AMH through the evolution of H. sapien traits with retention of H. ergaster traits (earliest), whilst the AMH group compromise clear AMH dating to less than 125,000 YA (Pettitt 2005: 132).  As Pearson (2008: 44) suggests, ‘the process of becoming modern likely occurred as a series of steps, regardless of whether one considers these different steps to be different taxa in a bushy phylogeny or merely different grades in a single evolving lineage’. Pearson (2008: 44) goes on to say that the ‘evolution of modern man should be viewed as a process rather than an event involving rapid morphological change due to drift during population bottlenecks and selection for new advantageous traits or genes, or a combination of the two’, rather than a singular smooth process.  Therefore we should be wary of relying purely on the often sparse fossil record.  Regardless, it is widely recognised that H. Sapiens are a probably daughter species of H. erectus (i.e. as a result of a speciation occurrence) which spread across Africa and into Western Eurasia at the beginning of,  or just before, the Middle Pleistocene (Jurmain et al. 2011, Rightmire 2008: 8).

Recent research has also led to five majority agreements in regards to the tenets of AMH behaviour (Table 2; Nowell 2010: 447). Wood (2005: 109) makes the salient point that early eurocentrism in the search for AMH behavioural origins clouded certain judgements, such as focusing on Western Europe to the detriment of African archaeological sites.

Points of Consensus on Modern Behaviour:

  • The relationship between modern anatomy and modern behaviour is more complex than once thought.
  • Modern behaviour has symbolic thoughts at its core.
  •  Archaeological record of the African Middle Stone Age has rendered invalid the idea of a ‘human revolution’ occurring for the first time in the Upper Palaeolithic of Western Europe.
  • Later Neandertal sites have demonstrated modern behaviour to either some form or some degree, such as personal adornment or symbolic behaviour.
  • The triad of social, cultural and demographic factors are key in understanding variability and patterning in the archaeology record.

Table 2. Agreed points in visioning the concept of modern behaviour (Balter 2011: 21, Nowell 2010: 447, Pettitt 2005, Zilhao 2006; 2010: 1025).

Research (Jurmain et al 2011, Prat et al 2012) has also highlighted symbolic  behaviour in a number of early H. Sapiens sites throughout Africa and the Near East; Balter (2011: 21) highlights Aterian sites in North Africa where various personal and possible symbolic artefacts have been found, whilst Blombos Cave in South Africa (77,000 YA), and Katanda in the DR of Congo (80,000 YA), have some of the earliest symbolic artefacts recovered including incised ochre, worked bone and beads; almost a full 45,000 years before any such artefacts appear in the European record (Jurmain et al. 2011: 298-299).   Mellars (2006: 9383) proposes a model that indicates climatic, environmental and cultural changes around 80,000 to 60,000 YA as major causative agents of cognitive change alongside population pressures in the dispersal of African H. Sapiens.  However Nowell (2010: 441) states that the gradual emergence of behaviours as a mosaic of features, and not as a single revolutionary package, should be considered within the archaeological record, whilst defining that for the majority of researcher’s symbolic language and codified social relationships define modern behaviour.  Mosaic features in fossil hominids have been noted in recent discoveries of the Australopithecus sediba specimen, highlighting a mix of Australopithecus and Homo anatomical features (Wong 2012: 25).

The origins of AMH living outside of Africa have led to the formation of two major competing models in palaeoanthropolog: the multi-regional continuity hypothesis that proposes already living populations of hominins and local populations in Asia, Europe and Africa continued their ‘indigenous evolutionary development from pre-modern Middle Pleistocene forms to anatomically modern human’ (Jurmain et al. 2011: 281), whilst the complete replacement (or out of Africa) hypothesis  proposes that AMH arose in Africa 200,000 YA to completely replace those in Europe and Asia (Table 3; Jurmain et al. 2011: 279).  Critical to the multi-regional hypothesis are the tenets that i) a level of gene flow between geographically separated populations prevented speciation, ii) all living humans derive largely from the species H. erectus, iii) natural selection in regional populations is responsible for the regional variants found in extant populations, and finally, iv) that the emergence of H. sapiens was not restricted to one area per se but was a phenomenon that occurred throughout the geographic range where ‘humans lived’ (Johanson 2001: 1).

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Table 3. Timeline of major H. sapiens discoveries, question marks denote tentative dates (Jurmain et al. 2011: 413) (Click to enlarge).

Critical to the complete replacement theory are that i) H. sapiens arose in one place, highly likely to be East/South Africa, ii) H. sapiens ultimately migrated out of Africa, and replaced all human populations without interbreeding, and that iii) modern human variation is a relatively recent phenomenon (Johanson 2001: 1).

Although not all factors of the multiregional hypothesis cannot be falsified, it seems prevalent that H. sapiens originated in Eastern Africa (with Ethiopia so far providing the most stable dated site), and dispersed to Europe and Asia from 65,000 YA onwards in various waves (Table 2; Jurmain et al. 2011: 282, Mellars 2006: 9381).    The two most securely dated sites in Europe for AMH are Pecstera Cu Oase in Romania at 42,000 YA and Buran Kaya III in the Crimea, Ukraine at 31,900 YA (Hoffecker 2009: 16040, Prat et al. 2011).  Unsurprisingly, Hoffecker (2009: 16040) notes that the issue of the mechanism of transition is a ‘controversial topic in palaeoanthropology’.  Arguments have been made that AMH crossed into Eurasia via a Levantine corridor, with the earliest AMH dates from Skhul and Qafzeh in Israel at around 120,000 to 100,000 YA (Wood 2005: 98), whilst recent work in North African Aterian populations from around the same period are pointed out as being possible ancestors to at least some of the H. sapiens who left Africa during this period (Balter 2011: 23).  The palaeoanthropological evidence suggests that they, the Aterians, possessed the right symbolic behaviour, anatomy and favourable climatic conditions to be at least a contender for contributing to one of the waves of H. sapiens leaving (Balter 2011: 22-23).  There are a variety of sites across Europe after 40,000 YA that show a variety of evidence for AMH presence, including the triad of modern human behaviour with symbolic artefacts and modern skeletal morphology.  However, we should not forget that Europe was already populated with the H. Neandertalensis species prior, and co-existed with H. sapiens for approximately 10,000 years or so (Hoffecker 2009: 16040, Wood 2005: 110).  This subject will be tackled shortly.

The most secured dates found in Asia are from areas such as the Sahul region (conjoined landmass of Australia, Papua New Guinea and Tasmania), where it is possible AMH occupied various areas (Wood 2005: 111-112).  It must be remembered that while the ‘dwarf’ species H. floresiensis survived up until 18,000 YA on the island of Flores with temporal overlap between themselves and H. sapiens, it seems unlikely there was regional overlap from the archaeological evidence (Wood 2005: 111).  Curnoe et a.l (2012: 1) note that the AMH fossil record for East Asia is, at this time, poorly recorded owing to a lack of detailed description, rigorous taxonomy classification and a distinct lack of accurately dated fossils.  However there are a few key sites: Liujiang in Southern China has produced a skeleton which, although it lacks exact stratigraphic position, has been dated to an estimated broad range from 153-30,000 YA, whilst the Niah Cave child in East Malaysia has been dated to 45-39,000 YA for the cranium from a recent field and lab program (Curnoe et al. 2012: 2).  Tianyuan cave, just south of the Zhoukoudian cave, has fragmentary evidence of an AMH crania and teeth which are dated to 40,000 YA, with a possible mix of archaic and modern features; the American and Chinese team who excavated it have suggested it is evidence of interbreeding in China with resident archaic populations, but suggest an African origin for the AMH itself (Jurmain et al. 2011: 287).

The above examples highlight problems in understanding the definition of AMH, both anatomically and behaviourally.  With the advent of dispersals from Africa AMH interacted with other hominids, prominent of which are the Neandertals in Eurasia and the elusive Denisovans in Siberia (Krause et al. 2010, Hubin 2009, Noonan 2010, Zilhao 2006).  Genetic evidence is unravelling what it is to be an AMH (Hawks et al. 2007), and there is evidence to suggest that Neandertals contributed up to 4% of non-African modern human DNA via gene flow (Green et al. 2010: 711, Reich et al. 2010: 1057).

Roughly one third of Neandertal mtDNA genetic diversity, dating from 70,000 to 38,000 YA, is comparable to contemporary human populations (Briggs et al. 2009:  319), although Noonan (2010: 550) and Herrera et al. (2009: 253) raise the flag of caution as the majority of Neandertal remains were not collected with their regard to DNA investigation, whilst modern DNA contamination, despite the safeguards, is still prevalent.  Briggs et al. (2009: 321) postulate that low mtDNA diversity throughout much of the Neandertal lineage may indicate a low effective population size, although it could be reflective of AMH direct/indirect  influences as they spread from Africa (interbreeding or out competing for example).  Herrera et al. (2009: 253) note that there are difficulties such as identifying haplotypes indicative of interbreeding.  Nonetheless, as Zilhao et al. (2010: 1027) points out that a Mid-Palaeolithic Iberian Neandertal sites shows distinct features associated with AMH including symbolic behaviour, with ochre and shells displaying evidence of body paint, and organisation skills, which that studies believes is the outcome of demographic pressure, technology and ‘social complexification’ within the Neandertal species itself (Roebroeks et al. 2012: 2).

Figure 1. Phylogenetic tree of complete mtDNA rooted with chimpanzee and bonobo mtDNA, showing geographic origin of mtDNA samples (Krause et al. 2010: 896) (Click to enlarge).

Figure 1. Phylogenetic tree of complete mtDNA rooted with chimpanzee and bonobo mtDNA, showing geographic origin of mtDNA samples (Krause et al. 2010: 896) (Click to enlarge).

Meanwhile Krause et al. (2010: 896) provide evidence that the Denisovans split before Neandertal and AMH at around 1 million YA, whilst Neandertals and H. sapiens ancestors split around 690,000 to 550,000 YA (Jurmain et al. 2011: 270).  Pairwise nucleotide differences indicate that Neandertals differ from modern humans at around 202 nucleotide positions whilst the Denisovan individual differs at 385 positions (Krause et al. 2010: 895), which alongside the phylogenetic evidence (Figure 1), supports a deeper divergence of the Denisovan hominin than between the closer related H. sapiens and Neandertal species.

There is the distinct possibility of admixture; this is reinforced by the apparent coexistence of the surrounding area by Neandertals, AMH and Denisovans in the Altai region at roughly the same time periods, and by the fact that Denisova populations contributed roughly 4-6% present day DNA in AMH Melanesian populations; this suggests they interacted with Melanesian ancestors, but probably not in the Siberia region (Krause et al. 2010: 895, Reich et al. 2010: 1053).  The lack of complete remains and its physically limited location from this suspected new species at Denisova Cave limit our knowledge but tests are continuing.  If this hominin, as hypothesised, had a wide geographical range (Reich et al. 2010: 1059), the question must be asked why we haven’t noticed it before?  Interestingly Abi-Rached et al. (2011: 94) highlight that the fact that as the AMH Eurasian populations mixed with archaic hominids, adaptive introgression of vital immune system components (Human Leukocytes Antigen class 1) helped to provide a mechanism for rapid evolution.  The adapted introgression of the genes now represent more than half of the HLA alleles in modern Eurasians, and were later introduced into African populations (Abi-Rached et al. 2011: 89).  Therefore the definition of AMH must include evidence of interbreeding to some degree.  Future genomic studies in other archaic hominins should provide more information relating to the relationships between species; however it seems clear that gene flow was relatively common in the Upper Pleistocene (Reich et al. 2010: 1059).

Increased AMH demographic growth and geographic spread dated from 80,000 YA to the present, has led to rapid genetic evolutionary selective pressures on features including ‘skin pigmentation, adaptation to cold and diet’ amongst others (Hawks et al. 2007: 20756).  Some of the most dramatic have been associated with the uptake of agriculture during the Neolithic period, both in terms of our ability in coping with disease and changes from interaction via population density (Barnes et al. 2011: 848).  This is partly the result of cultural and ecological reasons (i.e. a biocultural pathway), and Hawks et al. (2007: 20756-20757) remark that in their study it was noted ‘new adaptive alleles continued to reflect demographic growth, (that) the Neolithic and later periods would have experienced a rate of adaptive evolution >100 times higher than characterised most of human evolution’.  Two examples help highlight the effects of biocultural change in modern population; coevolution of humans and cattle since the Neolithic has resulted in distinct populations of modern humans becoming lactose persistence, such as Europeans, whilst other populations, such as African and Asian adults, are largely lactose intolerant (Jurmain et al. 2011: 313).  This is through active selection of breeding cattle which ‘inadvertently selected for the gene that produces lactose persistence in themselves’ (Jurmain et al. 2011: 313); this example shows the geographical distribution of lactose persistence is often related to a history of cultural dependency on fresh milk products.  On the other hand, modern population pressures include the admixture of populations who have had the pressures of urbanisation, agriculture and gene selection for disease loading (such as Tuberculosis) who then interact with indigenous populations, such as Torres Strait Islanders and Papua New Guinea populations, who are not predisposed to deal with TB because of their lack of long term cattle coevolution (Barnes et al. 2011).  The importance is recognising that there is great variation at an environmental genetic level in modern AMH, and this is highly likely to be the case during the long and concurrent evolution of AMH (Jurmain et al. 2011).

In conclusion the definition of AMH comes to thus; either a strict definition of AMH present at around 40-35,000 YA onwards, with the full suite of the triad of anatomically modern skeletal elements, modern behavioural & cognitive functions, and similar genetics to today’s worldwide population (Tattersall & Schwartz 2008), or we can take the view that H. sapiens evolved with a mosaic of features that they themselves appeared at different times during the evolution of AMH (Jurmain et al. 2011, Pettitt 2005).  It is this author’s belief that the origin of H. sapiens species lies at the Omo Kibish site in Eastern Africa as the earliest evidence so far, and the definition of AMH must be taken with accord of the fossil record (Jurmain et al. 2011).  Throughout this paper, a long chronology has been presented and discussed of H. sapiens in the context of human evolution, and consideration has been given to the relatively modern genetic changes in modern human populations (Hawks et al. 2007).  This view belies the complexity of defining AMH, especially as new hominins are found (Krause et al. 2010, Reich et al. 2010, Wong 2012), as the consideration of the context is paramount.  There is inherent variation in the record, as evidenced between the distinct morphological variation between Omo 1 and Omo 2 fossils, leading up to the palaeogenetic and modern genetic variation and morphological in populations from inside and outside Africa (Briggs et al. 2009, Hawks et al. 2007, Harvati et al. 2012).  In comparison, the origin of the Homo genus is still in dispute (Wong 2012: 24) and the chimpanzee fossil record is distinctly lacking (Wood 2005: 69-70).  Only recently has SNP genotyping revealed the extent of Pan troglodytes ellioti as a genetically distinct species (Bowden et al. 2012: 1).  The importance of this is that we should seek to place the well discussed H. sapiens within a larger framework of where hominins (both extant and extinct) diverged, interacted and evolved (see discussion- Patterson et al. 2006: 1106, Wakeley 2008).  The definition of AMH is therefore but one fragment of our long evolutionary history.

Further Sources:

Bibliography:

Abi-Rached, L.,  Jobin, M. J., Kulkarni, S., McWhinnie, A., Dalva, K., Gragert, L. Babrzadeh, F., Gharizadeh, B., Luo, M., Plummer, F. A., Kimani, J., Carrington, F., Middleton, D., Rajalingam, R., Beksac, M., Marsh, S. G. E., Maiers, M., Guethlein, L. A., Tavoularis, S., Little, A., Green, R. E., Norman, P. J., & Parham, P. 2011. The Shaping of Modern Human Immune Systems by Multiregional Admixture with Archaic Humans. Science. 334 (6052): 89-94.

Adler, D.S. et al., 2008. Dating the Demise: Neanderthal Extinction and the Establishment of Modern Humans in the Southern Caucasus. Journal of Human Evolution. 55: 817–833.

Balter, M. 2011. Was North Africa the Launch Pad for Modern Human Migrations?. Science. 331: 20-23.

Barnes, I., Duda, A., Pybus, O. G. & Thomas, M. G. 2011. Ancient Urbanization Predicts Genetic Resistence to Tuberculosis. Evolution. 65 (3): 842-848.

Bowden, R., Macfie, T. S., Myers, S., Hellenthal, G., Nerrienet, E. et al. 2012. Genomic Tools for Evolution and Conservation in the Chimpanzee: Pan Troglodytes Ellioti is a Genetically Distinct Population. PLoS Genet. 8 (3): 1-10. e1002504. doi:10.1371/journal.pgen.1002504

Briggs, A. W., Good, J. M., Green, R. E., Krause, J., Maricic, T., Stenzel, U., Lalueza-Fox, C., Rudan, P., Brajković D., Kućan, Z., Gusic, I., Schmitz, R., Doronichev, V. B., Golovanova L. V., Rasilla, M. D. E., Fortea, J., Rosas, A. & Pääbo, S. 2009. Targeted Retrieval and Analysis of Five Neandertal mtDNA Genomes. Science. 325 (5938): 318-321. doi:10.1126/science.1174462

Curnoe, D., Xeuping, J., Herries, A. I. R., Kanning, B., Tacon, P. S. C., Zhende, B., Fink, D., Yunsheng, Z., Hellstrom, J., Yun, L., Cassis, G., Bing, S., Wroe, S., Shi, H., Parr, W. C. H., Shengmin, H. & Rogers, N. 2012. Human Remains from the Pleistocene-Holocene Transition of Southwest China Suggest a Complex Evolutionary History for East Asians. PLoS ONE. 7 (3): 1-28. e31918. doi:10.1371/journal.pone.0031918

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Updates…

8 Sep

Apologies for the lack of updates; please bear with me.  I’ve had a busy past few weeks & the future doesn’t look any less busy! Preparation for moving down to start the Msc Human Osteology & Funerary Archaeology program at the University Sheffield have begun, but I’m still on the look out for a lab coat!  I move to the city shortly, but I’m still enjoying the time I have left in my hometown.  This year has flown by a bit too quickly!

The next Skeletal Series update will concern the human hip bones, and their form and function.  They are particularly key in both age and sex diagnosis of the individual.  I’ll also shortly start a brief write-up of the German Grampus placement & the activities we got up to, since I’ve finally just got round to finishing their report for the program online.

I did manage to read my way through Waldron’s (2009) ‘Palaeopathology’  manual whilst I was in Germany, and what a delight it was too! I’d highly recommend reading it, especially if you are going to be working with human bones from archaeological sites.  I have a feeling that this book, and the Human Bone Manual, will not be far from my side in the next few months.  ‘Palaeopathlogy’ offers ‘Operational Definitions’ which help to improve the diagnosis of disease in ancient human remains via clinical definitions and backgrounds. I would say this is a must have, especially since a lot of the palaeopathogical literature cannot be cross examined due to the differences in rational & criteria used.

A quick scan of BBC’s online news website reveals that a late stone age skull discovered from Iwo Eleru in Nigeria has some interesting ‘primative’ features associated with human evolution.  The online article can be found here at PLoS online.  The article deals with the chronology and morphology of the Iwo Eleru calvaria.  This is a very interesting article as it deals with a skull that shows similar morphological features present in archaic homo sapiens humans around 100,000 years ago but its found in a  context that is dated to around 15,000BP.  It is also rare that human remains are found during this date in West Africa.  The article states that this cranium fragment represents ‘evidence of deep population substructure in Africa and complex evolutionary processes for the origin of modern humans’, that the archaic homo sapiens didn’t just cut off after Anatomically Modern Humans (AMH) appeared.  Frankly, I think this also highlights what is often forgotten in the prehistoric & palaeolithic archaeological record.  It is not just migration out of Africa and the dispersal of AMH that is fascinating and interesting, but also to still keep looking and researching inside Africa to see the evolutionary and populational changes still concurrent with human expansion elsewhere.

I also noticed the other that over at John Hawks’s weblog he has announced the Malapa Soft Tissue project.  This project aims to discover if soft tissues from an ancient hominid has been preserved from the Malapa site cave site, just outside Johannesburg in South Africa.  Recently discussed in the National Geographic magazine, the hominids discovered at this site are believe do to be Australopithecus Sediba, a possible intermediate form between the Australopithecus & Homo genus.  Much information remains to be gleamed from these exciting and relatively complete finds.  Up to date information on the MST project can be found on the John Hawks link.  Perhaps one of the most interesting aspects of this project is that is it open access science; you are encouraged to take a part and offer your expertise!  Keep an eye on it and see where it leads…

I’ll be back shortly.

Further news on A. Sediba