Although domestic ducks have been important poultry species throughout human history, their origin remains enigmatic, with mallards and/or Chinese spot-billed ducks being proposed as the direct wild ancestor(s) of domestic ducks. Here, we analyzed 118 whole genomes from mallard, Chinese spot-billed, and domestic ducks to reconstruct their evolutionary history. We found pervasive introgression patterns among these duck populations. Furthermore, we showed that domestic ducks separated from mallard and Chinese spot-billed ducks nearly 38 thousand years ago (kya) and 54 kya, respectively, which is considerably outside the time period of presumed duck domestication. Thus, our results suggest that domestic ducks may have originated from another wild duck population that is currently undefined or unsampled, rather than from present-day mallard and/or Chinese spot-billed ducks, as previously thought. Overall, this study provides new insight into the complex evolution of ducks.
尽管家鸭是一个重要的家禽品种，但是它们的起源问题仍然存在争议。先前研究表明绿头野鸭与斑嘴鸭都可能是家鸭的祖先。为解析家鸭起源，我们对包含家鸭、绿头野鸭以及斑嘴鸭的118个基因组进行分析。结果表明家鸭与野鸭以及两个野鸭群体之间存在广泛的基因交流。进一步分析揭示家鸭与绿头野鸭以及斑嘴鸭分歧时间在3.8与5.4万年前，这一分歧时间远超家鸭假定的训化时间。此外，群体历史模拟结果表明家鸭可能起源于一个“幽灵”野鸭群体。因此，我们认为目前的家鸭可能并不是由绿头野鸭或斑嘴鸭驯化而来，而是起源于一种目前未被发现或者本研究中没有取样的野鸭群体。该研究结果为复杂的家鸭进化史提供了一个新见解。.
Keywords: Demographic histories; Domestication; Duck; Population structure.