Allopatry

Aims,Because rhinolophids,have,been,hypothesized,to use echolocation,call frequency to recognize conspecifics, sympatric species calling at similar frequencies should be subject to acoustic character displacement, i.e. a drift in frequency,values,to minimize,the,risk of misidentification,of conspecifics. However, it has been proposed that insufficient geographical separation between populations,in sympatry,and,allopatry,may,counter,the,establishment,of frequency,differences by character displacement. Here we tested the hypothesis that insular populations should exhibit acoustic divergence, and

We examined the morphological variability (23 morphometric traits) among individual Galaxias platei (N = 380) collected from 20 postglacial lakes in the southern Andes. The lakes were chosen to cover the latitudinal range of the species in Patagonia. Diet examined for a subset of these fish (N = 261) collected during the summer months (January through March), differed among river basins but there were no clear latitudinal trends in the consumption of any prey type. Diet may, however, have partially shaped morphology, as pelvic measures were negatively correlated with consumption of amphipods. Substantial differentiation among populations was observed, primarily in the shape and dimensions of the head, in caudal morphology and in fin length. Our results indicate that the morphology of G. platei varies with latitude, and may be related to risk of predation and diet. © 2006 The Linnean Society of London, Biological Journal of the Linnean Society, 2006, 87, 69–82.

Pyxicephalus currently contains three recognized species, viz. P. adspersus, P. edulis and P. obbianus, the former two of which have a long history of confusion. Parry (1982) described P. adspersus angusticeps from Beira, Mozambique, which was synonymized with P. edulis. We re-examine the taxonomic status of Pyxicephalus taxa from Mozambique, examining the types and contrasting them to congeners throughout Africa. Morphological characters previously used to delimit species in Pyxicephalus are examined, and problems with some identified. Additional diagnostic characters and their variation in Pyxicephalus are discussed, and a revised key is provided. Confusion among species in the genus, type localities, literature and folklore led to P. adspersus angusticeps being incorrectly synonymized with P. edulis. We formally revalidate P. angusticeps, and designate a lectotype for P. edulis. The identity of voucher specimens from previous work suggests that the breeding ecology of P. angustic...

Recent multilocus studies of congeneric birds have shown a pattern of elevated interspecific divergence on the Z chromosome compared to the autosomes. In contrast, intraspecifically, birds exhibit less polymorphism on the Z chromosome relative to the autosomes. We show that the four black-and-white Ficedula flycatcher species show greater genetic divergence on the Z chromosome than on the autosomes, and that the ratios of intraspecific polymorphism at Z-linked versus autosomal markers are below the neutral expectation of 75%. In all species pairs, we found more fixed substitutions and fewer shared polymorphisms on the Z chromosome than on the autosomes. Finally, using isolation with migration (IMa) models we estimated gene flow among the four closely related flycatcher species. The results suggest that different pattern of evolution of Z chromosomes and autosomes is best explained by the faster-Z hypothesis, since the estimated long-term gene flow parameters were close to zero in al...

Inland epigean freshwater amphipods of Romania are diverse and abundant for this region has a favourable geographical position between the Balkans and the Black Sea. Excluding Ponto-Caspian species originating in brackish waters and freshwater subterranean taxa, there are 11 formally recognized epigean freshwater species recorded from this country. They belong to 3 genera, each representing a different family: Gammarus (Gammaridae, 8 species or species complexes), Niphargus (Niphargidae, 2 epigean species) and Synurella (Crangonyctidae, one species). Their large-scale distribution patterns nevertheless remain obscure due to insufficient data, consequently limiting biogeographical interpretations. We provide extensive new data with high resolution distribution maps, thus improving the knowledge of the ranges of these taxa. Gammarus species display substantial altitudinal variability and patchy, fragmented distribution patterns. They occur abundantly, particularly in springs and strea...

Female-limited polymorphisms are widespread in odonates (Cordero & Andrés, 1996) and butterflies (Turner, 1978; Turner, 1983; Clarke et al., 1985; Herrell & Hazel, 1995; Nielsen & Watt, 2000), but appear also rarely in beetles (Bergsten, Toyra & Nilsson, 2001), copepods (Fava, 1988), lizards (Forsman & Shine, 1995; Galán, 2000) and hummingbirds (Bleiweiss, 1992). One important step in the study of these polymorphisms is to establish whether they are determined genetically. Moreover, if they are shared by closely related species, the ...

Female-limited polymorphisms are widespread in odonates (Cordero & Andrés, 1996) and butterflies (Turner, 1978; Turner, 1983; Clarke et al., 1985; Herrell & Hazel, 1995; Nielsen & Watt, 2000), but appear also rarely in beetles (Bergsten, Toyra & Nilsson, 2001), copepods (Fava, 1988), lizards (Forsman & Shine, 1995; Galán, 2000) and hummingbirds (Bleiweiss, 1992). One important step in the study of these polymorphisms is to establish whether they are determined genetically. Moreover, if they are shared by closely related species, the ...

The genetic structure of populations of closely related, sympatric species may hold the signature of the geographical mode of the speciation process. In fully allopatric speciation, it is expected that genetic differentiation between species is homogeneously distributed across the genome. In nonallopatric speciation, the genomes may remain undifferentiated to a large extent. In this article, we analyzed the genetic structure of five sympatric species from the plant genus Heliotropium in the Atacama Desert. We used amplified fragment length polymorphisms (AFLPs) to characterize the genetic structure of these species and evaluate their genetic differentiation as well as the number of loci subject to positive selection using divergence outlier analysis (DOA). The five species form distinguishable groups in the genetic space, with zones of overlap, indicating that they are possibly not completely isolated. Among-species differentiation accounts for 35% of the total genetic differentiati...