The house sparrow is the most widely distributed land bird species in the World. Its large natural distribution in Europe, Asia, and North Africa was probably facilitated by commensalism with human agriculture that expanded from the Middle East from about 10,000 years ago. It has been suggested that before the advent of agriculture an early glacial advance resulted in two disjunct ranges of house sparrows; in the Middle East and on the Indian subcontinent. According to this hypothesis, differentiation during this period of isolation resulted in the two major subspecific groups (the domesticus group and the indicus group). We sequenced 720 bp of the D-loop from the mitochondrial DNA control region from 103 house sparrows collected from 23 regions (14 countries) across the Palearctic distribution. No differentiation between the traditional indicus and domesticus groups was found in our analyses, indicating that the morphological differentiation between the domesticus and indicus groups may represent recent ecological adaptive divergence rather than ancient glacial isolation. Low levels of population differentiation as well as low genetic variation within populations is in accordance with a recent event of population expansion, possibly from one main source area in the Middle East where agricultural societies first arose.

Keywords