Résumé
Chromosomal divergence in wild populations of the house mouse has been considered a stasipatric speciation process. Numerous Robertsonian (Rb) centric fusions are fixed in the populations of Europe and Tunisia and involve almost all the acrocentric chromosomes of the standard 2n = 40 karyotype. The tempo and mode of fixation of these chromosomal mutations in nature as well as the evolutionary consequences of this differentiation remain for the most part misunderstood. Palaeontological data indicate that the house mouse has colonized (or recolonized) Europe during the Holocene. The dispersion of this commensal species is obviously related to human activity. The colonization of the Mediterranean area can be approximately dated region by region. This shows that chromosomal divergence occurs in very recent populations, i.e. for which the period of colonization is after the Bronze Age. No Rb populations have been observed in regions colonized by the house mouse before this period. This pattern suggests that chromosomal divergence in the house mouse may be related to the colonization wave. Several interpretations are presented to explain the relationship between the distribution and age of Robertsonian populations.