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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.

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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!

Find Out More

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.