The osteological microevolution of red junglefowl and domestic fowl under the domestication process

Abstract

Red junglefowl are regarded as the primary wild ancestor of domestic fowl and are thought to have been domesticated in multiple regions. The osteological microevolution of red junglefowl and domestic fowl during domestication, especially at the earliest stage, has still not been thoroughly investigated, despite the fact that a proper understanding of this process is required to chart the progress of domestication. In this paper, the major long bones of the modern wild red junglefowl, captive red junglefowl in cages, and domestic fowl from various breeds were measured and the data were compared using t-tests and analysis of covariance. The results showed that captive red junglefowl were generally smaller than wild red junglefowl but the distal part of tibiotarsus was relatively thicker in the former. In addition, parts of the wing bone were thinner in captive red junglefowl than in wild red junglefowl. Assuming the morphological difference between extant wild and captive red junglefowl is analogous to that between ancient wild and captive red junglefowl, these differences suggest that body size reduction and other morphological changes occurred in the earliest stage of the domestication process. These results will be useful for estimating the progress of domestication in red junglefowl archaeological remains and making comparisons with domestic fowl bones.