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Free keywords:
familiarity; imprinting; inbreeding; mate choice; social organization
Abstract:
The evolutionary divergence of cues for mate recognition can contribute to early stages
of population separation. We compare here two allopatric populations of house mice
(Mus musculus domesticus) that have become separated about 3000 years ago. We have
used paternity assignments in semi-natural environments to study the degree of mutual
mate recognition according to population origin under conditions of free choice and
overlapping generations. Our results provide insights into the divergence of mating
cues, but also for the mating system of house mice. We find frequent multiple mating,
occurrence of inbreeding and formation of extended family groups. In addition, many
animals show strong mate fidelity, that is, frequent choice of the same mating partners
in successive breeding cycles, indicating a role for familiarity in mating preference.
With respect to population divergence, we find evidence for assortative mating, but only
under conditions where the animals had time to familiarize themselves with mating
partners from their own population. Most interestingly, the first-generation offspring
born in the enclosure showed a specific mating pattern. Although matings between animals
of hybrid population origin with animals of pure population origin should have
occurred with equal frequency with respect to matching the paternal or maternal origin,
paternal matching with mates from their own populations occurred much more often.
Our findings suggest that paternally imprinted cues play a role in mate recognition
between mice and that the cues evolve fast, such that animals of populations that are
separated since not more than 3000 years can differentially recognize them.
