Animal Molecular Breeding, 2025, Vol.15, No.1, 19-28 http://animalscipublisher.com/index.php/amb 20 2 Origins and Historical Trajectories of Goose Domestication 2.1 Geographic centers and dual domestication events The domestication of geese mainly occurred in the two regions of East Asia and Europe. In East Asia, archaeological and genetic studies conducted by Eda et al. (2022) indicated that people in the lower reaches of the Yangtze River in China began domesticating swan goose (Anser cygnoides) approximately 7 000 years ago. This is one of the earliest known records of domestic poultry domestication. Kozák (2019) discovered that in Europe, the domestication of the greylag goose (Anser anser) began approximately around 4 000 BC. Genomic studies also support this view, indicating that domestic geese have a dual origin, that is, Chinese geese originated from swan goose, while European geese originated from greylag goose (Jing et al., 2022). Chinese geese show obvious geographical differentiation in terms of genes, while the origin of European geese is more complex, including genetic mixing with Chinese geese (Chen et al., 2023; Zhang et al., 2023). 2.2 Morphological and behavioral changes post-domestication During the domestication process of geese, many obvious morphological and behavioral changes occurred, such as weight gain, loss of migratory ability, change in feather color, early sexual maturity, and a significant increase in egg production (Kozák, 2019; Jing et al., 2022). Kozák (2019) reported that domestic geese such as Toulouse geese and African geese weighed more than 300% higher than their wild ancestors, and the egg production of some domestic geese increased by 600% to 1 200%. Some studies have also found that the unique forehead tumor structure of Chinese geese is related to certain specific genetic variations. The breeding process of domestic geese focuses on genes in aspects such as the nervous system, immunity, metabolism, vision, bone structure and blood oxygen transport, which reflects their continuous adaptation to the captive environment (Jing et al., 2022; Chen et al., 2023). 2.3 Historical hybridization and gene flow Heikkinen et al. (2020) found through genome-wide analysis that there has always been bidirectional gene flow between wild geese and domestic geese. Among the current European domestic geese, 3.2% to 58% of the genes come from wild greylag geese, and more than 10% of the ancestral origins are from Chinese domestic geese, indicating that multiple hybridization occurred at different stages (Figure 1). The research on mitochondrial and nuclear DNA by Heikkinen et al. (2015) and Honka et al. (2018) also found that although the overall genetic basis of domestic geese is relatively narrow, in some regions, there has been or is still gene exchange with wild species in the past. Ottenburghs et al. (2017) demonstrated that the evolutionary process of true geese was influenced by ancient interspecific gene infiltration, which led to a “patchwork genetic structure” in their genomes. 3 Phenotypic Traits Associated with Domestication 3.1 Plumage color and feather pattern variability Wild geese generally have grey feathers, but domestic geese have many different color types such as white, white and brown, and white and grey. White feathers have become the main type in many areas (Azalou et al., 2024). Wen et al. (2021) found through genetic research that the KIT gene is a key factor for the differences between white and gray feathers in Chinese domestic geese, especially a 18-base deletion mutation, which has a significant relationship with the characteristics of white feathers. Genes like TYRP1 are also believed to be related to feather color, especially in specific breeds such as Huoyan geese (Wen et al., 2023). Whether for aesthetic needs or practical uses, artificial selection has played a significant role in the appearance traits such as feather color during the domestication process. 3.2 Growth, body conformation, and reproduction The weight of domestic geese has significantly increased compared to their wild ancestors. Some breeds are even more than three times heavier than wild species (Kozák, 2019). The morphological studies of Abdel-Kafy et al. (2021) and Azalou et al. (2024) indicated that there were significant differences among different domestic geese in terms of body length, tarsal bone length, wingspan, chest circumference, etc., and male geese were generally larger than female geese. Domestic geese show earlier sexual maturity and higher egg production in terms of
RkJQdWJsaXNoZXIy MjQ4ODYzNA==