Tag Archives: Human Evolution

The Trials and Tribulations of Homo floresiensis: A Quick Introduction

1 Sep

I haven’t wrote about palaeoanthropology much recently, but I have been meaning to write about Homo floresiensis for a while now.  The diminutive hominin, most likely a new Homo species although this is still debated, was discovered by chance on the Indonesian island of Flores in 2003 during the excavation of the Liang Bua cave site, which was led by the now sadly deceased New Zealand archaeologist Mike Morwood (Brown et al. 2004).  The team that excavated at Liang Bua cave found the remains for a probable 12 separate H. floresiensis individuals dating from around 95,000 years ago to around 13,000 years ago (1), making H. floresiensis one of the last hominin species to live in conjunction with our species, H. sapiens (Brown et al. 2004: 1055).  One of the most complete individuals found at the site is LB1, an adult female aged around 30 who has almost both lower limbs, upper right arm, pelvis and cranium surviving (see image below).  It is this individual that has become the holotype, or type species, for H. floresiensis and on who most of the current research has, and continues, to focuses on (Brown et al. 2004, Brown 2012, Falk et al. 2005, Henneburg et al. 2014).

The majority of this research has been focused on the skeletal remains themselves and archaeological context as attempts to extract ancient DNA (aDNA) from the remains has not been successful, likely due to the cave environment that the skeletons were excavated from and the fragmentary nature of the surviving aDNA.  Morwood’s team formally announced the details of the skeletal remains in 2004 and stated that the remains included primitive and derived features resulting from long term isolation and endemic dwarfing (Brown et al. 2004: 1055-56).  It is important to note here that up until the excavation of H. floresiensis in 2003 it was thought that only H. erectus and H. sapiens were the only Homo hominins present in Late Pleistocene Asia (Brown et al. 2004: 1056).  Later hominin finds, such as at the Denisova Cave excavations in Siberia in 2010 and the announcement of the Denisovan species, have highlighted that other unknown hominins were present in Late Pleistocene Asian contexts helping to fundamental change, and challenge, the way that we think of the evolution of our species H. sapiens (Reich et al. 2010: 1053).

LB1

The species holotype is LB1, found in 2003 in the Liang Bua cave site on Flores, Indonesia. The adult female individual dates to 18,000 years old, stood 3.5 ft tall and represents one of the most complete H. floresiensis individuals found. Notice the large dentition relative to the overall cranium size. Image is not to scale. Image credit: Jennifer Clark (Human Origins Program) and Chip Clark (Smithsonian Institution).

There are many issues surrounding the remains of the H. floresiensis hominins that serve to obstruct and help obfuscate the research that has taken place into understanding the origin and anatomy of the floresiensis hominin.  Inevitability this is ongoing as McVie (2014) highlights in a recent Guardian newspaper article.  Thus it is pertinent to highlight them here to help understand where we are at with understanding the remains of the Flores hominin.  Indeed the H. floresiensis case has all the unfortunate tropes of a spectacular palaeoanthropological find (2) (the unexpectedness of the finds, the bickering academics, mishandling of remains etc.) and continues to show no sign of abating.

As is indicative above, H. floresiensis is a unique and interesting recent hominin ancestor, even more so as the only physical remains of the species are the 12 individuals found and excavated at the Liang Bua cave site in Indonesia.  It is the opposite to our modern notion of the (much maligned) Neandertal, being gracile, petite and small in statue and body.  Perhaps inevitably it was labelled a ‘hobbit’ species (although this word has led to problems with the Tolkein estate).  The type specimen LB1 was quickly repudiated as a H. sapiens individual with a pathology by several researchers and others who have, at various times, stated that all the H. floresiensis individuals, and in particular LB1 and partial skeleton LB6, display attributes varying from myxoedematous endemic cretinism (Oxnard et al. 2010, Brown 2012), Laron Syndrome (Falk et al. 2009, see Hawks 2007), or Down Syndrome (Benton 2014, Henneburg et al. 2014).  There have also comparisons even being made of the singularity of the Late Pleistocene epoch species being compared to the K/T impact boundary event 65 million years ago (Eckhardt et al. 2014), which frankly is a little mystifying.

McVie (2014) has highlighted a potential conflict of interest with regards to both the Eckhardt et al. (2014) and Henneburg et al. (2014) publications, as there is a suggestion that Henneburg (who helped author both articles) picked his reviewers to help favour his research team’s hypothesis and investigation.  The journal that both of the articles were recently published in, Proceedings of the National Academy of Sciences of the United States of America (or PNAS), does not operate a peer review policy in the recognised sense, as most of the other respected journals use, but uses its own specific and trusted system (see here).  Perhaps most surprising is the fact that this team have now published 3 separate papers each focusing on different pathological conditions each time in their continued belief that the H. floresiensis remains are probable members of H. sapiens and represent pathological processes (Henneburg et al. 2014).

Regardless of the ongoing new-species-or-not debate there must be further investigation of the context of the remains.  As Hawks (2007) highlights it is the exact nature of where H. floresiensis fits in both the evolutionary tree and the archaeological context of Asia that remains to be thoroughly demonstrated.  This can only be determined by further finds with consolidated archaeological contexts over an extensive period of time and, with luck, further specimens of this hopeful new species.  The specimens of this population found on Flores, Indonesia, are both tantalising for the human evolution implications and frustrating for their apparent uniqueness in location and time.  As such the Flores H. floresiensis remains are surely one of the most interesting and divisive points of interest in the palaeoanthropological world today.

Notes

(1). A new analysis of the chosen radiocarbon samples and the stratigraphy of the cave site by Sutikna et al. (2016) has led to a serious revision in the chronology of the Homo floresiensis fossils.  It seems that all fossil evidence of H. floresiensis is older than 60,000 years, which is a major revision and leaves a lot of questions regarding the contextual material culture and faunal remains and their association with the fossil hominins.  John Hawks has covered the implications that this new article by Sutikna et al. has in a detailed and interesting read, check it out here.

(2). An excellent counter example of this is the University of the Witwatersrand and National Geographic funded Rising Star project currently underway in South Africa, where the remains of a spectacular palaeoanthropological site (with the evidence of numerous hominin individuals of some importance) has been well and truly open to researchers and members of the public to take part in and to learn about.  This has included an extensive and on-going social media presence and an open call for researchers to join collaborative workshops to study the remains.

Lean More

  • The Smithsonian Institute has a handy guide in introducing the hominins of human evolution at the Human Origins website and, as a part of this, there is a nice guide to H. floresiensis.
  •  For a full round of the issues involved in the research of H. floresiensis and the LB1 type fossil, I highly recommend reading the Wikipedia entry on the species which covers all pertinent academic articles published.

Bibliography

Benton, A. 2014. Was the “Hobbit” a Human with Downs Syndrome? Probably Not. EvoAnth. Accessed 19/08/14. (Open Access).

Brown, P. 2012. LB1 and LB6 Homo floresiensis are Not Modern Human (Homo sapiens) Cretins. Journal of Human Evolution. 62 (2): 201-224.

Brown, P., Sutikna, T., Morwood, M. J., Soejono, R. P., Jatmiko, Wayhu Saptomo, E. & Rokus Awe Due. 2004. A New Small-Bodied Hominin from the Late Pleistocene of Flores, IndonesiaNature. 431 (7012): 1055–1061.

Eckhardt, R. B., Henneburg, M., Weller, A. S. & Hsu, K. J. 2014. Rare Events in Earth History Include the LB1 Human Skeleton from Flores, Indonesia, as a Developmental Singularity, not a Unique Taxon. PNAS. 111 (33): 11961-11966. (Open Access).

Falk, D., Hildebot, C., Smith, K., Morwood, M. J., Sutikna, T., Brown, P., Jatmiko, E. W. S., Brunsden, B. & Prior, F. 2005. The Brain of LB1, Homo floresiensis. Science. 308 (5719): 242-245.

Falk, D., Hildebolt, C., Smith, K., Jungers, W., Larson, S., Morwood, M., Sutikna, T., Jatmiko, E. W. S. & Prior, S. 2009. The Type Specimen (LB1) of Homo floresiensis Did Hot Have Laron Syndrome. American Journal of Physical Anthropology. 140 (1): 52-63.

Hawks, J. 2007. Another Diagnosis for a Hobbit. John Hawk’s Weblog. Accessed 24/08/14. (Open Access).

Henneberg, M., Eckhardt, R. B., Chavanaves, S. & Hsu, K. J. 2014. Evolved Developmental Homeostasis Disturbed in LB1 from Flores, Indonesia, Denotes Down Syndrome and Not Diagnostic Traits of the Invalid Species Homo floresiensis. PNAS. Early View: 1-6. (Open Access).

McKie, R. 2014. Homo floresiensis: Scientists Clash Over Claims ‘Hobbit Man’ was Modern Human with Downs Syndrome. The Guardian. Accessed 19/08/14.

Oxnard, C., Obendorf, P. J. & Kefford, B. J. 2010. Post-Cranial Skeletons of Hypothyroid Cretins Show a Similar Anatomical Mosaic as Homo floresiensis. PLoS ONE. 5 (9): 1-11. (Open Access).

Reich, D., Green, R. E., Kircher, M., Krause, J. Patterson, N., Durand, E. Y., Viola, B., Briggs, A. W. & Stenzel, U. et al. 2010. Genetic History of an Archaic Hominin Group from Denisova Cave in Siberia. Nature. 468 (7327): 1053–1060. (Open Access).

Sutikna, T., Tocheri, M. W., Morwood, M. J., Saptomo, E. W., Awe, R. D., Wasisto, S. … & Storey, M. 2016. Revised Stratigraphy and Chronology for Homo floresiensis at Liang Bua in Indonesia. Nature. In Press. doi:10.1038/nature17179.

Brief Updates: Archaeological Desks & Palaeoanthropology

17 May

The archaeologist Robert M Chapple has recently done something a bit special to celebrate his 100th post over at his blog.  In a thoughtful and entertaining entry Robert discusses the writing and thinking space of the humble desk, that much maligned friend of the archaeologist.  Indeed when a person thinks of an archaeologist the first thing that pops into a person’s head is the excitement of fieldwork in far-flung countries, a trowel perhaps, maybe some bones or Indiana Jones cracking his whip.  It is rarely the vital tool that is the desk, a space in which to hunker down, study site reports, books and process the archaeological record properly over a hot cup of tea, that pops into the minds of people asked to think about archaeology.

Yet the desk is where the action happens!  This is where the hard work of the amalgamation of knowledge happens, where the fieldwork is fleshed with the existing archive and the site is put within a larger context.  Interpretations are made and broken on the humble desk.  So Robert, recognising this vital space of thought and action, also saw it as a deeply personal space for the individual.  As such he asked a wide variety of his archaeological friends to send their own photographs of their desks for his 100th blog entry.  And it is a lovely entry, displaying both academic desks and personal spaces.  I was also asked to join in and you can see my little bedside table from which I am writing this now!  Although my work area is pretty bare compared to the desks (and fantastic 2 or 3 screen adapted computers) on show here, I got a serious longing for the university library where I carried out the majority of my dissertation research.

In other news I have produced a small article for the Teesside Archaeology Society TEESCAPES magazine.  I was kindly asked to write for them by my good friend Spencer Carter, who is the edited of the magazine and a specialist in studying and understanding the context of prehistoric microlithics.  Spencer is currently researching the Mesolithic period of northern England and his fantastic Microburin site, which documents his research and outreach work, can be found here.  My article, which was published in the 2014 Spring Edition of TEESSCAPES, focuses on the amazing palaeoanthropological highlights of 2013 and specifically mentions the Georgian site of the Homo erectus finds at Dmanisi (1), the Spanish site of Sima de la Huesos, and the Rising Star South African project.  It is an informal look back on year of research and excavations that bought much to the table in terms of our of knowledge of understanding human evolution.  (I may also have sneaked in an Alan Partridge joke).

teesscapes_2014-01_cvr

A great Spring 2014 edition of TEESSCAPES by the Teesside Archaeological Society with articles on a variety of topics including, but not limited to, history and archaeology in the national curriculum, the Mesolithic forests of the coast of NE England, museum reviews, Streethouse before the Saxons and human evolution. There are also field notes and books reviews. Read more about the editor’s views, Spencer Carter, in his enlightening blog on post on publishing and editing archaeology journals and open access in archaeology over at Microburin here.

I’ve tried to frame the article within a basic introduction to palaeoanthropology, some of the major new techniques being used in the study of past populations and some of the problems in trying to understand the fossil record and of human evolution in general.  It is a short article but I have to say I am very impressed by the presentation of the article, so a big thank you Spence!  I hope to start producing articles for TAS as and when I can, but this aside I would urge any reader to check it out and to check out any local archaeology societies or companies near to you.  They really are a wealth of original research and really help you get to grips with what is going on in your region and further abroad.  My own article also includes a cheeky photography of me in a lab coat which is sadly, at the moment, a rare occasion.  If you are an archaeologist, a student archaeologist or someone who just manages to engage in their passion between sleep and work then I heartily recommend jumping in and writing for your local society!

Notes

(1).   The article is a review of the amazing palaeoanthropological finds and research of 2013 and as such is likely to become out of touch with the passing of years, as new research highlights new evidence or different perspectives are investigated, hypothesized and studied in-depth.  A good example of this is the fairly recent claim that the Dmanisi individuals, discussed in my article, could possibly (but unlikely) represent different lineages of hominin species (check out Jamie Kendrick’s site The Human Story for more information on this issue and for in-depth entries on human evolution in general).

Further Information

  • Learn about the Teesside Archaeology Society here.
  • Current and past editions of TEESSCAPES can be found here.
  • Robert M Chapple’s awesome blog can be found and read here.
  • Spencer Carter’s fantastic Microburin site can be read here.

Evolutionary Thoughts

7 Apr

I’m currently writing an essay on the origins and definitions of Anatomically Modern Humans (Homo sapiens species), and it is an endlessly fascinating (and confusing!) topic.  Recent finds and reports have complicated the picture but have also opened up the delightful hominin evolutionary line (Jurmain et al 2011).  It is also necessarily a wide ranging subject with researchers pinpointing various features of AMH throughout the palaeoanthropological record (Jurmain et al 2011, Pettitt 2005, Tattersall & Schwartz 2008).  By seperating out the modern skeletal anatomymodern behavioural characteristics and genetic information as they appear in the fossil and archaeological record, it is my view that this approach highlights the ever changing nature of what it means to be a modern human.  This triad approach allows the investigator to realise that different aspects of what is typically expressed as AMH traits (Tattersall & Schwartz 2008: 50), whilst taken as a whole, can also be expressed at differing times due to several factors.

From our earliest anatomically modern traits described in the crania of Omo Kibish 1 & 2 from 195,000 years ago (Pettitt 2005), to cultures and symbolic behaviour attributed to populations throughout Africa by 100,000 years ago, and the evidence of the first dispersals of AMH out of Africa around 80,000-60,000 years ago (Wood 2005), it is clear that AMH have spread far beyond their homeland.  However the continuing work of researchers in Africa and elsewhere in the world has also highlighted the rentention of archaic features in certain AMH populations; examples include the intriguing Iwo Eleru crania found in Nigeria (Harvatie 2011, and Dienekes’ Anthropology post here) and the recently described Chinese skeletal remains reporting a complex evolutionary history of East Asian AMH (Curnoe et al 2012).  This can be attributed to various reasons, such as the admixture of those AMH with archaic hominids or population isolation.

Recent email communication with my friend and fellow blogger Confusedious has also highlighted the varied genetic changes in recent populations of Homo sapiens.  His excellent post on gene culture coevolution is a detailed and elegant essay discussing rapid and modern genetic changes in H. sapiens regarding disease loading in populations, gene expression and selective gene adaptation; largely as a result of agricultural uptake and increased population density (Barnes et al 2011, Hawks et al 2007).  Recent molecular work on the origin of TB (Smith et al 2009 & previously wrote about here by me) has helped highlight the need for a nuanced approach in treating the disease in modern populations.  Examples include indigenous Papua New Guinea people and the Torres Strait Islanders, who do not have a genetic history of coevolution with the disease from the practise of intense animal husbandry, and who are now threatened by today’s demographic pressure and population expansion of those who do, and who have selectively adapted to it (Barnes et al 2011).

In conclusion, the gestalt of the Homo sapiens species may be instantly recognizable to some (Tattersall & Schwartz 2008), but there are a number of factors that intertwine, such as skeletal morphology, genetic change and behavioural adaptations, that produce a species that emerged roughly 200,000 years ago and are continuing in their adaptations to this world.

Bibliography:

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

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

Harvati, K., Stringer, C., Grun, R., Aubert, M., Allsworth-Jones, P., & Folorunso, C. A. 2011. The Later Stone Age Calvaria from Iwo Eleru, Nigeria: Morphology and Chronology. PLoS ONE. 6 (9): e24024. doi:10.1371/journal.pone.0024024

Hawks, J., Wang, E. T., Cochran, G. M., Harpending, H. C. & Moyzis, R. K. 2007. Recent Acceleration of Human Adaptive Evolution. Proceedings of the National Academy of Sciences. 104 (52): 20753-20758.

Jurmain, R., Kilgore, L. & Trevathan, W. 2011. The Essentials of Physical Anthropology, International Edition.Belmont:Wadsworth.

Pettitt, P. 2005. ‘The Rise of Modern Humans’. In Scarre, C. (ed) The Human Past: World Prehistory & the Development of Human Societies. London: Thames & Hudson. pp 124-175.

Smith, N. H. Hewinson, R. G. Kremer, K. Brosch, R. & Gordon, S. V. 2009. Myths and Misconceptions: The Origin and Evolution of Mycobacterium tuberculosisNature Reviews: Microbiology. Vol 7: 537-544.

Tattersall, I. & Schwartz, J. H. 2008. The Morphological Distinctiveness of Homo Sapiens and Its Recognition in the Fossil Record: Clarifying the Problem. Evolutionary Anthropology. 17: 49-54.

Wood, B. 2005. Human Evolution: A Very Short Introduction. Oxford: Oxford University Press.