Красный индейка: главный дикий предок современной домашней курины

The red junglefowl: The principal wild ancestor of the modern chicken | Mangsatabam Dinachandra Meetei Before There Was the Chicken Long before domestication, junglefowl lived across the forests, woodland edges and human-modified landscapes of South and Southeast Asia. Among them, the red junglefowl (Gallus gallus) provided the principal wild ancestral contribution to the domestic chicken, commonly designated Gallus gallusdomesticus. Genome-wide research points parti- cularly to mainland Southeast Asian red junglefowl populations, including those related to Gallus gallus spadiceus, as important sources of ancestry in domestic chickens. However, later movement, selective breeding, admixture and interbreeding created a much more complicated genetic history. The chicken did not emerge through a simple, straight evolutionary path. Its history is better understood as a branching story involving domestication, human movement and later genetic exchange. Meet the Wild Ancestor The male red junglefowl is a striking bird, with a bright red comb and wattles, golden-orange neck and saddle feathers, dark wings and a long tail. Females are smaller and predominantly brown, with cryptic plumage that helps them remain concealed. Red junglefowl can occupy a variety of habitats, including areas influenced by agriculture and human settlement. This adaptability brought some populations into repeated contact with people—an encounter that eventually changed the history of both birds and humans. The Junglefowl Family The genus Gallus contains four living species: the red junglefowl, grey jungle-fowl (Gallus sonneratii), green or Javan junglefowl (Gallus varius), and Sri Lankan junglefowl (Gallus lafayettii). These are distinct species and should not be viewed as four equal ancestral lines of the domestic chicken. Genome-wide evidence indicates that the red junglefowl made the dominant ancestral contribution. The grey junglefowl lineage contributed genetic material to some domestic chicken populations, while evidence for contributions from the green and Sri Lankan junglefowls remains more limited or uncertain. From Wild Bird to Domestic Chicken The precise timing and location of chicken domestication remain debated. Some genetic studies have suggested a history beginning roughly 8,000 years ago, while other research has proposed different dates and scenarios. Genetic estimates of population diver- gence do not necessarily represent the beginning of domestication; archaeological evidence for securely identified domestic chickens becomes clearer during the second millennium BCE, particularly in mainland Southeast Asia. South and Southeast Asia—including areas around southwestern China and mainland Southeast Asia—appear to have been important in the early history of chicken domes- tication, but no single domestication centre has been universally established. Human interaction with junglefowl may initially have involved hunting, capture, keeping birds or using their eggs. Over generations, people began retai- ning and breeding birds with desirable characteristics. Artificial selection gradually changed traits such as body size, plumage, behaviour, reproduction and productivity. As people migrated and traded, chickens travelled with them, spreading across Asia and eventually to other parts of the world. A Complicated Family Tree Mitochondrial DNA has revealed multiple maternal lineages among domestic chickens, consistent with a complex history involving more than one maternal lineage. However, mitochon- drial DNA represents only the maternal lineage and cannot reconstruct the complete ancestry of the chicken genome. Genome-wide studies provide a broader picture. They confirm the dominant contribution of red jungle-fowl ancestry while also detecting genetic exchange with other Gallus species, particularly the grey junglefowl. Introgression is the movement of genetic material from one population or species into another through hybridisation and subsequent backcrossing. It does not mean that the donor species independently evolved into the chicken. (To be contd)