title: Ancestry of the Iban is predominantly Southeast Asian: genetic evidence from autosomal, mitochondrial, and Y chromosomes.
abstract: Humans reached present-day Island Southeast Asia (ISEA) in one of the first major human migrations out of Africa. Population movements in the millennia following this initial settlement are thought to have greatly influenced the genetic makeup of current inhabitants, yet the extent attributed to different events is not clear. Recent studies suggest that south-to-north gene flow largely influenced present-day patterns of genetic variation in Southeast Asian populations and that late Pleistocene and early Holocene migrations from Southeast Asia are responsible for a substantial proportion of ISEA ancestry. Archaeological and linguistic evidence suggests that the ancestors of present-day inhabitants came mainly from north-to-south migrations from Taiwan and throughout ISEA approximately 4,000 years ago. We report a large-scale genetic analysis of human variation in the Iban population from the Malaysian state of Sarawak in northwestern Borneo, located in the center of ISEA. Genome-wide single-nucleotide polymorphism (SNP) markers analyzed here suggest that the Iban exhibit greatest genetic similarity to Indonesian and mainland Southeast Asian populations. The most common non-recombining Y (NRY) and mitochondrial (mt) DNA haplogroups present in the Iban are associated with populations of Southeast Asia. We conclude that migrations from Southeast Asia made a large contribution to Iban ancestry, although evidence of potential gene flow from Taiwan is also seen in uniparentally inherited marker data.
authors.affiliation: Department of Human Genetics, University of Utah, Salt Lake City, Utah, United States of America.
authors.forename: Tatum S
authors.initials: TS
authors.lastname: Simonson
authors.forename: Jinchuan
authors.initials: J
authors.lastname: Xing
authors.forename: Robert
authors.initials: R
authors.lastname: Barrett
authors.forename: Edward
authors.initials: E
authors.lastname: Jerah
authors.forename: Peter
authors.initials: P
authors.lastname: Loa
authors.forename: Yuhua
authors.initials: Y
authors.lastname: Zhang
authors.forename: W Scott
authors.initials: WS
authors.lastname: Watkins
authors.forename: David J
authors.initials: DJ
authors.lastname: Witherspoon
authors.forename: Chad D
authors.initials: CD
authors.lastname: Huff
authors.forename: Scott
authors.initials: S
authors.lastname: Woodward
authors.forename: Bryan
authors.initials: B
authors.lastname: Mowry
authors.forename: Lynn B
authors.initials: LB
authors.lastname: Jorde
mesh_terms: D001210:Asia, Southeastern; D044466:Asian People / Q000235:genetics; D002877:Chromosomes, Human; D041322:Chromosomes, Human, Y; D004272:DNA, Mitochondrial; D004641:Emigration and Immigration; D005828:Genetics, Population; D006801:Humans
chemical_list: D004272:DNA, Mitochondrial