Geoff Clark

Dr. Geoff Clark

Department of Pharmacology and Toxicology, University of Louisville, Louisville, United States

Research Focus & Metrics

Academic Career Length

31Years (1996-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

View All Publications
3 October 2016 in Nature
Verified
Journal Article
Open access
PDF file
PSPontus Skoglund
Pontus Skoglund
CPCosimo Posth
Cosimo Posth
KSKendra Sirak
Kendra Sirak
MSMatthew Spriggs
Matthew Spriggs
FVFrederique Valentin
Frederique Valentin
DRDavid Reich
David Reich
Analysis of ancient DNA from four individuals who lived in Vanuatu and Tonga between 2,300 and 3,100 years ago suggests that the Papuan ancestry seen in present-day occupants of this region was introduced at a later date. Pacific islanders today have been found to have ancestry from a mixture of lineages including Papuan, Australian and East Asian. David Reich and colleagues now report analysis of ancient genomic data from four individuals from Vanuatu and Tonga, South Pacific islands, representing the first ancient genomic data from Oceanian populations. Their analysis finds no evidence of Papuan ancestry in the early Remote Oceanians, suggesting that Papuan ancestry seen in contemporary Pacific islanders may reflect later migration. The appearance of people associated with the Lapita culture in the South Pacific around 3,000 years ago1 marked the beginning of the last major human dispersal to unpopulated lands. However, the relationship of these pioneers to the long-established Papuan people of the New Guinea region is unclear. Here we present genome-wide ancient DNA data from three individuals from Vanuatu (about 3,100–2,700 years before present) and one from Tonga (about 2,700–2,300 years before present), and analyse them with data from 778 present-day East Asians and Oceanians. Today, indigenous people of the South Pacific harbour a mixture of ancestry from Papuans and a population of East Asian origin that no longer exists in unmixed form, but is a match to the ancient individuals. Most analyses have interpreted the minimum of twenty-five per cent Papuan ancestry in the region today as evidence that the first humans to reach Remote Oceania, including Polynesia, were derived from population mixtures near New Guinea, before their further expansion into Remote Oceania2,3,4,5. However, our finding that the ancient individuals had little to no Papuan ancestry implies that later human population movements spread Papuan ancestry through the South Pacific after the first peopling of the islands.

27 February 2018 in Nature Ecology & Evolution
Verified
Journal Article
Closed access
PDF file
CPCosimo Posth
Cosimo Posth
KNKathrin Nägele
Kathrin Nägele
HCHeidi Colleran
Heidi Colleran
FVFrédérique Valentin
Frédérique Valentin
SBStuart Bedford
Stuart Bedford
APAdam Powell
Adam Powell

2 April 2007 in Oncogene
Verified
Journal Article
Closed access
NAN P C Allen
N P C Allen
HDH Donninger
H Donninger
MVM D Vos
M D Vos
KEK Eckfeld
K Eckfeld
LHL Hesson
L Hesson
GCGeoff Clark
Geoff Clark

1 May 2016 in Journal of Archaeological Science
Verified
Journal Article
Closed access
TFTravis Freeland
Travis Freeland
BHBrandon Heung
Brandon Heung
DBDavid V. Burley
David V. Burley
GCGeoff Clark
Geoff Clark
Anders KnudbyAnders Knudby
Anders Knudby

1 October 2016 in Seminars in Cell & Developmental Biology
Verified
Journal Article
Closed access
HDHoward Donninger
Howard Donninger
MSM. Lee Schmidt
M. Lee Schmidt
JMJessica Mezzanotte
Jessica Mezzanotte
TBThibaut Barnoud
Thibaut Barnoud
GCGeoff Clark
Geoff Clark

10 October 2018 in PLOS ONE
Verified
Journal Article
Open access
PDF file
AAAtholl Anderson
Atholl Anderson
GCGeoff Clark
Geoff Clark
SHSimon Haberle
Simon Haberle
THTom Higham
Tom Higham
MNMalgosia Nowak-Kemp
Malgosia Nowak-Kemp
ACAaron Camens
Aaron Camens
The estimated period in which human colonization of Madagascar began has expanded recently to 5000–1000 y B.P., six times its range in 1990, prompting revised thinking about early migration sources, routes, maritime capability and environmental changes. Cited evidence of colonization age includes anthropogenic palaeoecological data 2500–2000 y B.P., megafaunal butchery marks 4200–1900 y B.P. and OSL dating to 4400 y B.P. of the Lakaton’i Anja occupation site. Using large samples of newly-excavated bone from sites in which megafaunal butchery was earlier dated >2000 y B.P. we find no butchery marks until ~1200 y B.P., with associated sedimentary and palynological data of initial human impact about the same time. Close analysis of the Lakaton’i Anja chronology suggests the site dates <1500 y B.P. Diverse evidence from bone damage, palaeoecology, genomic and linguistic history, archaeology, introduced biota and seafaring capability indicate initial human colonization of Madagascar 1350–1100 y B.P.