Polynesian chickens in the New World: a detailed application of a commensal approach

Abstract

In 2007, based on direct radiocarbon dates, we presented evidence that chickens were introduced to Chile before Europeans first made contact with the New World. The pre‐Columbian age of the chicken bones and their mtDNA affinities with one of two prehistoric Pacific chicken haplogroups (E) led us to conclude that Polynesia was the most likely origin for these pre‐Columbian chickens. Subsequently, the mtDNA and radiocarbon evidence provided has been applied to a range of studies and occasionally reinterpreted. This has revealed issues related to the brevity of the initial report in 2007. Here, we provide a full discussion of the evidence, including the relevant archaeological, historical and biological information necessary to provide the context for interpreting genetic analyses and understanding their implications for addressing archaeological questions. We include a comprehensive analysis of the isotope data within a geographical and temporally relevant dataset to verify the pre‐Columbian age of the El Arenal chickens. In addition, we provide longer DNA sequences obtained from some of the ancient Chilean chicken remains to address objections raised by critics and to demonstrate that longer sequences do not change the observed affinities of the mtDNA sequences, nor their interpretation. In this analysis, historical information is used to critically evaluate the results of phylogenetic analyses. This comprehensive approach demonstrates that the examination of modern chicken DNA sequences does not contribute to our understanding of the origins of Chile's earliest chickens. Interpretations based on poorly sourced and documented modern chicken populations, divorced from the archaeological and historical evidence, do not withstand scrutiny. Instead, this expanded account will confirm the pre‐Columbian age of the El Arenal remains and lend support to our original hypothesis that their appearance in South America is most likely due to Polynesian contact with the Americas in prehistory.

The Western Route Migration: A Second Probable Neolithic Diffusion to Indonesia

“…The dispersal continues through Peninsula Malaysia and western Indonesia, Nusa Tenggara and into the Pacific (Larson et al 2007). Modern chicken genetic studies have indicated multiple domestication events between South Asia and Thailand (Fumihito et al 1996;Liu et al 2002;Storey et al 2013), with Haplogroup D chickens potentially being introduced to ISEA via Peninsula Malaysia and western Indonesia. The presence of different and distinctive lineages of pigs and chickens in the Philippine archipelago argues against an Austronesian introduction of these domestic animals into ISEA (Larson et al 2007;Blench 2010), and at present it appears that of all the potential domesticated animals (pig, dog and chicken) from Taiwan/Philippines, it is only the chicken that was dispersed more widely (Thomson et al 2014).…”

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

“…As a result, they provide an opportunity to study colonization events and subsequent movements for islands and regions where they were successfully introduced, especially through the use of biomolecular techniques, including ancient DNA. In the AsiaPacific region, the complex histories of Pacific island colonizations have been investigated using the biological elements associated with these cultures, such as bottle gourds (7,8), sweet potatoes (9), pigs (10,11), dogs (12), Pacific rats (13), and chickens (14)(15)(16)(17). However, studies of commensals and domesticates in the Pacific to date have provided limited resolution of dispersal routes, due to low amounts of genetic diversity in many groups and overwriting of genetic signals by subsequent introductions, especially for cotransported species like rats (10,13,18).…”

“…Previous studies of modern and ancient chickens have identified both haplogroup D and E in the Pacific (14)(15)(16)(17)26), making interpretation of colonization history difficult due to potentially contrasting origins and dispersal histories (24). Indeed, the presence of haplogroup E in the Pacific has been used to infer a link between Polynesia and pre-Columbian South America, although both the phylogenetic signal and radiocarbon dating of the samples have been questioned (27)(28)(29).…”

“…Indeed, the presence of haplogroup E in the Pacific has been used to infer a link between Polynesia and pre-Columbian South America, although both the phylogenetic signal and radiocarbon dating of the samples have been questioned (27)(28)(29). This issue has recently taken on more significance as other studies of ancient genetic diversity in South America emphasize the importance of evidence for pre-European Polynesian contact (17,30).…”

Biological Anthropology in the Indo-Pacific Region: New Approaches to Age-Old Questions

“…Established in part due to the lack of access to human remains in the Pacific (see introduction), this approach uses aDNA and modern DNA of commensal animals and plants as a model to establish the human origins and settlement of the region (Larson et al, 2007;Matisoo-Smith et al, 2009;Oskarsson et al, 2011;Storey et al, 2013). Results of these studies indicate significant complexity and a range of origins of the different commensal animals in the region; with the origin and movement of pigs, dogs, chickens and rats all suggesting different ancestral sources, paths through island Southeast Asia into the Pacific, and differing timings and numbers of introductions (Matisoo-Smith, 2015).…”