Worth a Thousand Words
This week our featured image comes from a recently published manuscript entitled, Ancestry of the Iban Is Predominantly Southeast Asian: Genetic Evidence from Autosomal, Mitochondrial, and Y Chromosomes.
The picture below is Figure 1*of the manuscript and is a map of generalized migration patterns of populations into Island Southeast Asia (ISEA). The arrows in the image point to three migration events: the migration route along the Sundaland land bridge, the south-to-north migrations from Indonesia, and the Neolithic gene flow from Taiwan to modern ISEA.
From the paper’s 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.
The manuscript is by Tatum Simonson, Jinchuan Xing, Robert Barrett, Edward Jerah, Peter Loa, Yuhua Zhang, W. Scott Watkins, David Witherspoon, Chad Huff, Scott Woodward, Bryan Mowry and Lynn Jorde. It is freely available for you to comment on, read, rate and share.
* PLEASE NOTE: With regard to the figure legend in the image: The following location numbers should be switched: 18 and 20; 61 and 63.