We reviewed the distribution of Robertsonian (Rb) races of Mus musculus domesticus in central and southern Italy. This Rb system is called the Apennine system and includes four races (Cittaducale, ICDE, 2n=22; Ancarano, IACR, 2n=24; Campobasso, ICBO, 2n=22; Colfiorito, ICOL, 2n=33–34) surrounded by standard populations with karyotype 2n=40. Here we evaluate the relationships between the altitudinal distribution of races, and the indoor vs. outdoor behaviour of populations, inferred from literature data on the diet of the barn owl Tyto alba. We assume that a higher prevalence of mice in owl pellets reflects a higher outdoor occurrence of mice. The IACR and ICDE races were found at higher altitudes than the standard populations, while the ICBO race is present at lower altitudes like the standard race. The standard race has indoor and outdoor populations; in all the Rb races an indoor life has been suggested by our data. This behaviour is only partly due to altitude, since the ICBO race also lives at sea level. We speculated that indoor life is an intrinsic characteristic of the ICBO race irrespective of the environment. This pattern reinforces the idea that indoor life, through its population dynamics, has played a significant role in the evolutionary history of Rb races.
We combined mitochondrial (cyb, control region, coi, nd4) and nuclear (irbp, ghr, sry, lcat) DNA sequence data to infer phylogenetic relationships of arvicoline voles. The concatenated supermatrix contained 72.8 % of missing data. From this dataset, Bayesian inference showed close relationships of Arvicola and Chionomys, Proedromys with Lasiopodomys and Microtus gregalis, Phaiomys with Neodon and M. clarkei. Genus Microtus formed a supported group with Blanfordimys and N. juldaschi. The gene partition taxon sets were explained in the multilocus phylogeny in such a way that the resulting Bayesian inference tree represented a unique solution on a terrace in the tree space. This means that although the supermatrix contained a large proportion of missing data, it was informative in retrieving a phylogeny with a unique optimality score, tree likelihood.
The phylogenetic relationships in the myrmicine ant genus Myrmecina were analyzed using 1,281 bp of the mitochondrial cytochrome c oxidase I gene. Intermorphic queens observed in M. graminicola (Europe), M. nipponica (Japan), M. americana (North America; reported for the first time) and M. sp. A (Java) were reconstructed as an ancestral trait in this genus. Molecular-clock-based age estimates suggest that queen polymorphism evolved in Myrmecina at the latest during the Miocene. In terms of biogeographical regions, the inferred chronological order of divergence is: (oriental, (nearctic, (western palearctic, eastern palearctic))).