Tracing Human History Through Feathers: Mapping Ancient Migrations Through DNA

 By: Andrei Enrico N. San Diego | Harbinger

We know chickens as something we consume, but who knew that analyzing the DNA of the Gallus gallus can reveal hints and clues about the migrations and activities of people living in that region. Within the island chains of southwestern Philippines lies the Sulu Archipelago, where a groundbreaking study revealed the migration patterns and activities of people who lived alongside them through the mitochondrial DNA of chickens. The chickens in the archipelago revealed the genetic history, culture, and migration patterns of human communities in that region, highlighting how animal genetics can serve as a biological record of human movement, trade, and interaction across generations.

The experts studied a sample of 254 village chickens across the islands of the Sulu archipelago. With this, they have found five (5) major haplogroups in the chickens: A, B, C, D, and E. The most frequent haplogroup being haplogroup D (56.9%), representing the initial and most diverse chicken lineage in island southeast Asia. The DNA was extracted from the body feathers of the village chickens as it is the safest way to extract DNA without harming the chickens. Additionally, mitochondrial DNA was used because unlike other DNA, the mitochondrial DNA came from the maternal side only, which means it can be used as an ideal genetic marker for tracing maternal ancestry across generations. The DNA was then sequenced and compared to reference data to show relationships among the chickens. With this study, it provides a clear maternal lineage tracking and additional insights into genetic diversity although since it focuses on maternal lineage only, the paternal lineage and recombination were not addressed.

Based on the results of the study, it was identified that Sulu chickens are closely related to the chickens from neighboring islands such as Borneo, Sulawesi, and Sumatra. This indicated that there was a strong regional connection between these neighboring islands. Additionally, genetic relationships were visualized through media-joining networks that showed chickens were genetically mixed across islands suggesting that active trades, cultural exchange, and migrations were present within the human population.

Interestingly, Sulu chickens lack the polynesian D motif, which is a unique genetic marker found in chickens from Polynesia, Luzon, and Visayas. This hinted that the Sulu chickens followed a southern/western maritime pathway connecting them to Indonesia. The absence of this genetic marker suggests that Sulu chickens derived from a maternal lineage apart from the ones in the Pacific, this calls for further archaeological and DNA research to better understand chicken and human routes and movements.

With this research study, it showed that by just studying village chickens’ DNA it can reveal a grand tapestry of human movement, trade, and cultural entanglement and connections that shaped the ancient Philippines. This study highlighted how animals as simple as a chicken can serve as a living record that reveals our past. This demonstrated that by studying the mitochondrial DNA of the Gallus gallus, it provided amazing insights and delved deeper into the ancestral human migrations and cultural exchanges in island southeast Asia, specifically the Sulu archipelago.