Zoology最新文献

Islands provide excellent settings for studying the evolutionary history of species, since their geographic isolation and relatively small size limit gene flow between populations, and promote divergence and speciation. The endemic Bolle's Laurel Pigeon Columba bollii is an arboreal frugivorous bird species distributed on laurel forests in four islands of the Canary archipelago. To elucidate the population genetics, we genotyped ten microsatellite loci using DNA obtained from non-invasive samples collected across practically all laurel forest remnants, and subsequently grouped into eight sampling sites. Analyses including F-statistics, Bayesian clustering approaches, isolation by distance tests and population graph topologies, were used to infer the genetic diversity and the population differentiation within and among insular populations. Additionally, we evaluated the effect of null alleles on data analysis. Low genetic diversity was found in all populations of Bolle’s Laurel Pigeon, with no significant differences in diversity among them. However, significant genetic differentiation was detected among all populations, with pigeons from La Palma and El Hierro exhibiting the closest affinity. Bayesian clustering supported population separation between islands, and also detected fine-scale structure within the Tenerife and La Gomera populations. Our results suggest that, despite columbids have a high movement ability, they can show signature of genetic divergence among populations, particularly on oceanic islands. Geological history of the islands and distribution range of habitats could have close influence on the evolutionary trajectories of these birds. This approach can provide practical tools to implement appropriate conservation measures for range-restricted species and their habitat.

Living at high altitudes impose physiological and ecological challenges to which species may respond altering their body size, body proportions, and the shape of their body parts. Despite the importance of this topic for understanding the origin of species diversity, little attention has been invested in this phenomenon at the populational level. This paper study the relationship between altitude and body size, body proportions, and forewing shape venation of two populations of the parasitoid wasp Cotesia flavipes. Wasps were collected from Diatraea spp. larvae from sugarcane crops in two Colombian mountain ranges that cover between 600 m and 2143 m of altitude. Linear measurements of different body regions and geometric morphometrics of the forewing were subject to multivariate comparisons and allometric analyses to assess variation and to compare trends between ranges. Central (600 m to 1704 m) and Eastern Cordillera (877 m to 2143 m) populations showed different trends between body size and altitude. Allometric trends were not uniform within or between populations nor between structures. The allometric slopes of five body measurements from a single altitude differed from these from its own mountain range suggesting that body size trends along the cordilleras are a consequence of altitude and not of intrinsic body resource allocation processes. Wing shape between populations differed; however, these changes were poorly related to altitude. In agreement with recent studies in other groups, the observed allometric and wing shape differences between the two C. flavipes populations could be a plasticity response to altitude with interesting implications for posterior genetic differentiation.