Domestication and Genetics: What a Comparison Between Land and Aquatic Species Can Bring?

Abstract

Domestication , which is by definition a long and endless process, was one of the most significant cultural and evolutionary transitions of human history. In land, the domestication of animals started about 12,000 years ago and resulted in an apparent dichotomy between domesticated and wild animals. Nevertheless, new findings suggest that long-term gene flow between wild and captive land animal populations was much more common than previously assumed challenging assumptions about genetic bottlenecks during domestication, expectations about monophyletic origins, and interpretations of multiple independent domestication events. Besides, it raises new questions regarding ways in which behavioral and phenotypic domestication traits were maintained, and just what a domestic population was. In contrast to land animals, the onset of the domestication of aquatic species is a recent phenomenon, which started in the 1980s for most species. Hence, today there are still lots of exchanges between wild and captive individuals, and thus, captive fish have only slightly changed from their wild congeners. To better describe the diverse strategies for fish production, a new classification was recently developed comprising five levels of domestication with 1 being the least domesticated to 5 being the most domesticated. The recent domestication of fish species, and the diversity of domestication levels, provides a unique opportunity to better understand how genetic variability evolves during the early phases of fish domestication that could also be useful to discuss both the domestication history of land animals and concepts, such as domestication itself and the differences between wild and domesticated animals.