Field workThis site is dedicated to field work by ACAD members.
Reconstructing human colonization routes in the pacific using chicken DNA
Vanuatu Field Report 2012
Peggy MacQueen, ARC Research Associate
Humans have been present across much of the Pacific for only a few thousand years, and the colonization of the remote islands in this region represents a remarkable achievement in early navigation and survival. Seafaring people are thought to have migrated into the Pacific from Southeast Asia, reaching islands as far east as Tonga approximately three thousand years ago. By around seven hundred years ago, this vast migration had resulted in the colonization of all habitable islands in the Pacific, including the more remote eastern Pacific islands of Hawaii and Rapa Nui, and the southern islands of New Zealand.
Human settlement resulted in major changes in the fauna and flora of these previously uninhabited islands. Early colonisers brought with them a range of new species, including domesticates such as pigs, dogs and chickens. Archaeological and historical evidence indicate that these and other, non-domesticated species grew in abundance as the native fauna on the islands declined, presumably due to high hunting pressure, predation and competition, and as people became more reliant on domesticated species for food.
Chickens were an important part of the colonization process and their bones have been found in relatively large numbers in archaeological sites across the Pacific. For this reason, they provide us with a novel way of tracing ancient human movements in the region. It appears that wherever humans went, chickens went too. In an Australian Research Council funded project at ACAD, we have been using DNA obtained from archaeological chicken bones to trace the movement of this species from its origins in Asia and across the Pacific. We are also analyzing modern DNA extracted from chicken feathers collected in Island Southeast Asia and on Pacific islands. This is because genetic analyses of contemporary villiage, feral and native populations of chickens (or 'junglefowl', the wild ancestor of the domestic chicken) may still provide evidence of the diversity once present in historical populatons.
As part of this research, Peggy was lucky enough to travel to Vanuatu, an archipelago in the western Pacific, to collect feathers from village chickens on four islands: Efate, Malakula, Uri and Uripiv. Peggy travelled by boat and small plane between the islands and sampled a small number of chickens from as many villages as possible. Two excellent and long-suffering field workers on the islands proved essential in explaining her rather strange project to Village Chiefs and farmers. They became practiced at describing the aims of the study and the need for just a couple of feathers from different male and female birds. They were also much more adept at catching the chickens than Peggy, and when even they failed, at recruiting bands of small children to the job.
New Zealand coprolite fieldwork, February-July 2010
Jamie Wood, Research Associate
The research programme on the diets of New Zealand’s extinct avian megaherbivores and effects of their extinction on indigenous vegetation communities is a collaboration between Landcare Research, New Zealand, and the Australian Centre for Ancient DNA. A summary of the project can be seen at www.landcareresearch.co.nz/research. Fieldwork was carried out at 4 different localities:
- In February we recovered a large number of coprolites (probably kakapo) from a small cave (discovered by Alan Cooper and family in the 1980s.) near the Cobb Valley, in the Northwest Nelson region at the top of the South Island. Reconnaissance of marble outcrops on nearby Mount Mytton failed to find any sites suitable for coprolite preservation, but we did discover bones from two individual skeletons of crested moa (Pachyornis australis); the first bones of this species to be found on the mountain.
- The following week we spent three rainy days sampling kakapo coprolites from Honeycomb Caves Scientific Reserve on the West Coast of the South Island.
- A gap in the weather while working at the Honeycomb Caves allowed us to spend two days on the nearby Garibaldi Plateau. After a spectacular helicopter flight into this remote and largely inaccessible area, we visited Euphrates Cave where kakapo coprolites had previously been reported. Unfortunately we could not relocate these, but we did discover an important new deposit of moa coprolites near the main entrance to the cave.
- In July we revisited the Dart River Valley in the mountains of the southern South Island. We collected additional coprolite specimens from a site that is providing us with an incredibly detailed picture of moa feeding ecology, habitat use, and inter-specific niche segregation. Although the weather was clear and fine, it was cold. The overhang we were working in did not get above 1°C all day, and the night time temperatures were around -8°C.
Acknowledgements: Our thanks to the New Zealand Department of Conservation for permits and assistance facilitating this fieldwork, and to the Royal Society of New Zealand Marsden Fund
Sardinia Field Report, August 2009
Clio Der Sarkissian, PhD Candidate
The Australian Centre for Ancient DNA was invited to participate in the excavation of four caves in the Mediterranean island of Sardinia in August 2009. These caves are remarkably rich in mortuary artefacts some of which were dated around at 7,000 to 6,000 years ago, making them important relics of the Middle-late Neolithic period. Among these artefacts, human and animal remains, fragments of pottery, mollusk shells, obsidian arrowheads, a stone axe, as well as a very rare example of rock art were discovered. The richness and diversity of these mortuary deposits suggest that spirituality may have been fairly important and complex in Sardinian Neolithic communities.
Clio, from the Australian Centre for Ancient DNA collected human samples on site for further ancient DNA analysis back at the University of Adelaide as part of its participation in the Genographic Project. Sampling human remains directly from the archaeological site provides an exceptional opportunity to maximize the chance of retrieving authentic ancient DNA from valuable samples. DNA undergoes post-mortem degradation that is challenging in itself for palaeogeneticists but is also accompanied by the problem of contamination by modern DNA. Protective equipment such as gloves, facemasks and full-body suits was therefore worn to collect the samples in conditions reducing the risk of contamination.
Sardinians have been described as European genetic outliers and their origin is still veiled in mystery. Ancient DNA recovered from the individuals buried in these Sardinian caves holds the key to better comprehending who these Neolithic farmers were. It could also help investigate the previously hypothesised role of the obsidian trade in the peopling of Sardinia. Moreover, genetic information from Neolithic Sardinian individuals would be very valuable to understand the population dynamics and evolutionary processes that shaped the unique gene pool of Sardinians since the Neolithic. Finally, being the oldest DNA retrieved in Sardinia, ancient DNA from these Neolithic specimens would give a snapshot of the genetic diversity at a time point close to the first settlement of Sardinia and thus shed light on the origins of Sardinians.
The project, directed by Dr. Robin Skeates of the Department of Archaeology, Durham University, UK, is entitled ‘Journeys to the Underworld: Ritual Transformations of Persons, Objects and Caves in Neolithic Central Sardinia’.
Excavations are sponsored by the British Academy, and the Prehistoric Society.
The work is being undertaken (1) with the permission of the Direzione Generale per i Beni Archeologici (Roma), (2) in collaboration with the Soprintendenza per i Beni Archeologici per le Provincie di Sassari e Nuoro, Dott.ssa Giusi Gradoli (COMET – Valorizzazione Risorse Territoriali) Dr. Terrence Meaden (Department of Continuing Education, Oxford University, UK), and (3) with the assistance of the Comune di Seulo.
Mt. Cripps, Tasmania Field Trip, 2009
Jessica Metcalf, ARC Research Associate.
The limestone karst area of Mount Cripps, Tasmania houses over 200 caves hidden within a densely vegetated rainforest. Many of these caves are deep and vertical in nature and likely acted as pitfall traps to animals. Luckily for scientists, the cool environment of these caves has preserved a large number of animals over time. In fact, some of the youngest megafauna deposits in Australia have been discovered in the caves of Mount Cripps. As part of an ARC Discovery research project in which we are using ancient DNA to investigate the environmental impacts of climate change and humans on animal populations over time, our goal was to find well preserved animal bones, in particular native wallaby Macorpus rufogresius and extinct megafauna such as the short faced kangaroo, stenurineX.
Paleontology PhD candidate Aaron Camens, ancient coprolite specialist Jamie Wood, volunteer Bastien Llamas, and I teamed up with caving experts Lyndsey and Paul Darby of the Savage River Caving Club, and National Geographic photographers Amy and Matt.
A previous field trip in 2006, during which 18 caves were surveyed, revealed the location of three potential interesting deposits. We spent most of our time excavating these deposits and discovered quite a few animal skeletons to collect, including extinct megafauna! Currently, Jessica is extracting DNA from the collected samples and Aaron is preparing the remainder of skeletons for the Queen Victoria Museum.
Teouma Field Report, July 2008
Christina Adler, PhD Candidate
The Teouma archaeology site is a Lapita cemetery located on the south east coast of Efate, Vanuatu. The Lapita people colonised the pacific between 4 000 and 7000 years ago and are thought to be the ancestors of Polynesians. They are characterised by their notched pottery, domesticated animals and developed navigational skills in combination with their homogenous Austronesian language that was linguistically distinct from the pre-existing Australoid and Papuan populations of Melanesia. The Teouma Lapita site was discovered in 2004 consisting of an extensive cemetery of 50 burials and is still in the progress of uncovering further human remains. Associated with the remains are numerous fragmented, decorated and undecorated Lapita pots. The discovery of the pots and their link to the mortuary practices is a rare finding.
The genetic makeup of the Lapita people is unknown, with debate over a South East Asian origin or greater admixture with Melanesian coastal groups during their migration to Polynesia. A focus of my PhD to elucidate the ancestry of the Polynesian people from ancient DNA of Lapita remains.
This archaeology site provided the means to access freshly excavated skeletal material that improves the chances of extracting authentic ancient DNA, uncontaminated with modern human DNA. I attended the dig sit for two weeks in July to sample human skeletal remains. The sampling was performed in a sterile fashion, using gloves and face masks. Samples were recovered from four individuals located in a small burial pit off the main dig site. These consisted of near complete skeletons in various degrees of disarticulation caused by disturbances from coconut roots. This provides a unique opportunity to analyse DNA from previously uncovered Lapita remains, with the majority of studies to date using museum specimens. In addition it enables us to examine a past human population from which their most recent common ancestor is yet to be determined, aiding in the knowledge of past population migrations in the Pacific area.