Population Biology Commons^™

The Maintenance Of Phenotypic Divergence Through Sexual Selection: An Experimental Study In Barn Swallows Hirundo Rustica, Rebecca Safran, Yoni Vortman, Brittany R. Jenkins, Joanna K. Hubbard, Matt Wilkins, Rachel J. Bradley, Arnon Lotem

School of Biological Sciences: Faculty Publications

Previous studies have shown that sexual signals can rapidly diverge among closely related species. However, we lack experimental studies to demonstrate that differences in trait-associated reproductive performance maintain sexual trait differences between closely related populations, in support for a role of sexual selection in speciation. Populations of Northern Hemisphere distributed barn swallows Hirundo rustica are closely related, yet differ in two plumage-based traits: ventral color and length of the outermost tail feathers (streamers). Here we provide experimental evidence that manipulations of these traits result in different reproductive consequences in two subspecies of barn swallow: (H. r. erythrogaster in North …

Comparative Population Genomics Of Latitudinal Variation In Drosophila Simulans And Drosophila Melanogaster, Heather E. Machado, Alan O. Bergland, Katherine R. O'Brien, Emily L. Behrman, Paul S. Schmidt, Dmitri A. Petrov

School of Biological Sciences: Faculty Publications

Examples of clinal variation in phenotypes and genotypes across latitudinal transects have served as important models for understanding how spatially varying selection and demographic forces shape variation within species. Here, we examine the selective and demographic contributions to latitudinal variation through the largest comparative genomic study to date of Drosophila simulans and Drosophila melanogaster, with genomic sequence data from 382 individual fruit flies, collected across a spatial transect of 19 degrees latitude and at multiple time points over 2 years. Consistent with phenotypic studies, we find less clinal variation in D. simulans than D. melanogaster, particularly for the autosomes. Moreover, …

Tiger Salamanders Disappearing In Region, Dennis M. Ferraro

School of Biological Sciences: Faculty Publications

"Where have all the salamanders gone?" 'This is a question I have been increasingly asked over the past five to six years from area residents. It seems we are observing a dramatic population decline of the western barred tiger salamander in parts of Southeast Nebraska. The western barred tiger salamander (Ambystoma mavortium) is one of only two salamanders in Nebraska. Over the past two years, none have been found in southeast Nebraska.

Salamanders, like all amphibians, are excellent indicator species. In many cases they act like the iconic canary in the mine shaft, telling us when to run …

Measuring The Robustness Of Network Community Structure Using Assortativity, Daizaburo Shizuka, Damien R. Farine

School of Biological Sciences: Faculty Publications

The existence of discrete social clusters, or ‘communities’, is a common feature of social networks in human and nonhuman animals. The level of such community structure in networks is typically measured using an index of modularity, Q. While modularity quantifies the degree to which individuals associate within versus between social communities and provides a useful measure of structure in the social network, it assumes that the network has been well sampled. However, animal social network data is typically subject to sampling errors. In particular, the associations among individuals are often not sampled equally, and animal social network studies are often …