Using ancient DNA to study the origins and dispersal of ancestral Polynesian chickens across the Pacific

The human colonization of Remote Oceania remains one of the great feats of exploration in history, proceeding east from Asia across the vast expanse of the Pacific Ocean. Human commensal and domesticated species were widely transported as part of this diaspora, possibly as far as South America. We sequenced mitochondrial control region DNA from 122 modern and 22 ancient chicken specimens from Polynesia and Island Southeast Asia and used these together with Bayesian modeling methods to examine the human dispersal of chickens across this area. We show that specific techniques are essential to remove contaminating modern DNA from experiments, which appear to have impacted previous studies of Pacific chickens. In contrast to previous reports, we find that all ancient specimens and a high proportion of the modern chickens possess a group of unique, closely-related, haplotypes found only in the Pacific. This group of haplotypes appears to represent the authentic founding mitochondrial DNA chicken lineages transported across the Pacific, and allows the early dispersal of chickens across Micronesia and Polynesia to be modeled. Importantly, chickens carrying this genetic signature persist on several Pacific islands at high frequencies, suggesting that the original Polynesian chicken lineages may still survive. No early South American chicken samples have been detected with the diagnostic Polynesian mtDNA haplotypes, arguing against reports that chickens provide evidence of Polynesian contact with pre-European South America. Two modern specimens from the Philippines carry haplotypes similar to the ancient Pacific samples, providing clues about a potential homeland for the Polynesian chicken.Vicki A. Thomson, Ophélie Lebrasseur, Jeremy J. Austin, Terry Hunt, David Burney, Tim Denham, Nicolas J. Rawlence, Jamie R. Wood, Jaime Gongora, Linus Girdland Flink, Anna Linderholm, Keith Dobney, Greger Larson, Alan Cooper

Ancient DNA reveals elephant birds and kiwi are sister taxa and clarifies ratite bird evolution

Author version made available in accordance with Publisher copyright policy.The evolution of the ratite birds has been widely attributed to vicariant speciation, driven by the Cretaceous breakup of the supercontinent Gondwana. The early isolation of Africa and Madagascar implies that the ostrich and extinct Madagascan elephant birds (Aepyornithidae) should be the oldest ratite lineages. We sequenced the mitochondrial genomes of two elephant birds and performed phylogenetic analyses, which revealed that these birds are the closest relatives of the New Zealand kiwi and are distant from the basal ratite lineage of ostriches. This unexpected result strongly contradicts continental vicariance and instead supports flighted dispersal in all major ratite lineages. We suggest that convergence toward gigantism and flightlessness was facilitated by early Tertiary expansion into the diurnal herbivory niche after the extinction of the dinosaurs

Disabling XAuthors, Disordering TextsX: Deconstructing Disability and Identity in ChangingX Times

Drawing on Badiou’s writing, we develop new insights on some central notions of the discourse on “disability.” We offer eight agonistic, intersecting trajectories addressing these concepts. Drawing on authorial voices, we criticize the grammatical and rhetorical maneuvers we have previously undertaken as we represent ourselves aiming for forms of participatory engagement, thus offering both critique and self-critique. Previous poststructuralist accounts in this area have drawn on “philosophers of difference,” but mainly Deleuze and Guattari. This piece offers innovation in harnessing aspects of Badiou’s thinking to issues surrounding “discourses of disability” and notions of the research “self” in its various “impersonations.

More than one way of being a moa: differences in leg bone robustness map divergent evolutionary trajectories in Dinornithidae and Emeidae (Dinornithiformes).

The extinct moa of New Zealand included three families (Megalapterygidae; Dinornithidae; Emeidae) of flightless palaeognath bird, ranging in mass from 200 kg. They are perceived to have evolved extremely robust leg bones, yet current estimates of body mass have very wide confidence intervals. Without reliable estimators of mass, the extent to which dinornithid and emeid hindlimbs were more robust than modern species remains unclear. Using the convex hull volumetric-based method on CT-scanned skeletons, we estimate the mass of a female Dinornis robustus (Dinornithidae) at 196 kg (range 155-245 kg) and of a female Pachyornis australis (Emeidae) as 50 kg (range 33-68 kg). Finite element analysis of CT-scanned femora and tibiotarsi of two moa and six species of modern palaeognath showed that P. australis experienced the lowest values for stress under all loading conditions, confirming it to be highly robust. In contrast, stress values in the femur of D. robustus were similar to those of modern flightless birds, whereas the tibiotarsus experienced the highest level of stress of any palaeognath. We consider that these two families of Dinornithiformes diverged in their biomechanical responses to selection for robustness and mobility, and exaggerated hindlimb strength was not the only successful evolutionary pathway

Limitations and recommendations for successful DNA extraction from forensic soil samples: a review

Abstract not availableJennifer M. Young, Nicolas J. Rawlence, Laura S. Weyrich, Alan Coope

A deposition mechanism for Holocene miring bone deposits, South Island, New Zealand

Localised deposits of Late Pleistocene and Holocene bird bones occur in wetlands throughout New Zealand. These are characterised by dense accumulations of mostly disarticulated bones, with assemblages dominated by large, flightless bird taxa; in particular the extinct ratite moa (Aves: Dinornithiformes). A wide range of deposition mechanisms were historically proposed for these sites, including large floods and stampedes during wildfires. We outline a simple method for analysing the orientation and spatial distribution of bones within these deposits using GIS software, and apply this method to the interpretation of three such deposits from South Island, New Zealand. The results are consistent with non-catastrophic, periodic miring of individual moa. Long bones within these sites were preferentially orientated and subhorizontally inclined, indicating post-deposition disarticulation and movement of the bones within the sediment by sediment liquefaction and raking from the legs of mired birds, with a possible influence from water flow. Small, light skeletal elements were significantly under represented in the deposits. This may be due to post-mortem scavenging or weathering of vertebra and crania, 'pumping' to the surface of light, buoyant elements during liquefaction events, or crushing of these elements by subsequently mired birds.Jamie R. Wood, Trevor H. Worthy, Nicolas J. Rawlence, Susan M. Jones, and Stephen E. Readhttp://www.journaltaphonomy.com/JT-articles/2008/issue1-2008-abstacts.ht

The effect of climate and environmental change on the megafaunal moa of New Zealand in the absence of humans

New Zealand offers a unique opportunity to investigate the response of extinct megafaunal ecosystems to major changes in climate and habitat prior to human settlement. Prior to this point (late 13th Century AD) New Zealand contained a diverse avian megafauna dominated by nine species of large flightless ratite moa (Dinornithiformes). We used ancient DNA approaches to generate mitochondrial DNA sequence data from 39 crested moa (Pachyornis australis) and 145 heavy-footed moa (Pachyornis elephantopus) specimens. In combination with radiocarbon dating and dietary isotope analysis we examined the effects of Late Pleistocene and Holocene climate and environmental change on the phylogeography, palaeodemographics, and eventual extinction of Pachyornis. We show that Pachyornis changed altitudinal, longitudinal and latitudinal ranges through the Late Quaternary in response to alterations in the distribution of suitable habitat. However, we found no evidence for large-scale change in population sizes during the past 40,000 radiocarbon years BP (approximately 44,000 calendar years BP), or significant changes in δ13C and δ15N isotope signatures over this time period. The results suggest that crested moa tracked habitat through time with little consequence to population size. For the more broadly distributed heavy-footed moa, changes in climate and habitat distribution may have promoted phylogeographic structuring. Overall this study suggests that the likelihood of megafaunal extinction in New Zealand was greatly reduced in the absence of humans.Nicolas J. Rawlence, Jessica L. Metcalf, Jamie R. Wood, Trevor H. Worthy, Jeremy J. Austin and Alan Coope

Coprolite deposits reveal the diet and ecology of the extinct New Zealand megaherbivore moa (Aves, Dinornithiformes)

Copyright © 2008 Elsevier Ltd All rights reserved.The discovery in New Zealand of Late Holocene deposits of coprolites from extinct avian megaherbivores has provided a unique opportunity to gain a detailed insight into the ecology of these birds across ecologically diverse habitats. Macrofossil analysis of 116 coprolites of the giant ratite moa (Aves, Dinornithiformes) reveals a diverse diet of herbs and low shrubs in both semi-arid and high rainfall ecological zones, overturning previous models of moa as dominantly browsers of trees and shrubs. Ancient DNA analysis identified coprolites from four moa species (South Island giant moa, Dinornis robustus; upland moa, Megalapteryx didinus; heavy-footed moa, Pachyornis elephantopus and stout-legged moa, Euryapteryx gravis), revealing a larger dietary variation between habitat types than between species. The new data confirm that moa fed on a variety of endemic plant taxa with unusual growth forms previously suggested to have co-evolved with moa. Lastly, the feeding ecologies of moa are shown to be widely different to introduced mammalian herbivoresJamie R. Wood, Nicolas J. Rawlence, Geoffery M. Rogers, Jeremy J. Austin, Trevor H. Worthy and Alan Cooperhttp://www.elsevier.com/wps/find/journaldescription.cws_home/636/description#descriptio

Myth or relict: does ancient DNA detect the enigmatic Upland seal?

Abstract not availableAlexander T. Salis, Luke J. Easton, Bruce C. Robertson, Neil Gemmell, Ian W.G. Smith, Marshall I. Weisler, Jonathan M. Waters, Nicolas J. Rawlenc