Data from: Sex without sex chromosomes: genetic architecture of multiple loci independently segregating to determine sex ratios in the copepod Tigriopus californicusHeather J. Alexander, Jean M. L. Richardson, Suzanne Edmands & Bradley R. Anholt
Sex determining systems are remarkably diverse and may evolve rapidly. Polygenic sex determination systems are predicted to be transient and evolutionarily unstable yet examples have been reported across a range of taxa. Here we provide the first direct evidence of polygenic sex determination in Tigriopus californicus, a harpacticoid copepod with no heteromorphic sex chromosomes. Using genetically distinct inbred lines selected for male- and female-biased clutches, we generated a genetic map with 39 SNPs across 12...
Mating with multiple partners is common across species, and understanding how individual males secure fertilization in the face of competition remains a fundamental goal of evolutionary biology. Game theory stipulates that males have a fixed budget for reproduction that can lead to a trade-off between investment in precopulatory traits like body size, armaments, and ornaments, and postcopulatory traits such as testis size and spermatogenic efficiency. Recent theoretical and empirical studies have shown that if males...
Data from: Quantitative analysis of the ecological dominance of benthic disaster taxa in the aftermath of the end-Permian mass extinctionElizabeth Petsios & David J. Bottjer
The end-Permian mass extinction, the largest extinction of the Phanerozoic, led to a severe reduction in both taxonomic richness and ecological complexity of marine communities in its aftermath, eventually culminating in a dramatic ecological restructuring of communities. During the Early Triassic recovery interval, disaster taxa proliferated and numerically dominated many marine benthic invertebrate assemblages. These disaster taxa include the bivalve genera Claraia, Unionites, Eumorphotis and Promyalina, and the inarticulate brachiopod Lingularia. The exact nature and...
Data from: Population genomic analysis uncovers African and European admixture in Drosophila melanogaster populations from the southeastern United States and Caribbean IslandsJoyce Y. Kao, Asif Zubair, Matthew P. Salomon, Sergey V. Nuzhdin & Daniel Campo
Drosophila melanogaster is postulated to have colonized North America in the past several 100 years in two waves. Flies from Europe colonized the east coast United States while flies from Africa inhabited the Caribbean, which if true, make the south-east US and Caribbean Islands a secondary contact zone for African and European D. melanogaster. This scenario has been proposed based on phenotypes and limited genetic data. In our study, we have sequenced individual whole genomes...
Embryogenesis is the coordinated assembly of tissues during morphogenesis through changes in individual cell behaviors and collective cell movements. Dynamic imaging, combined with quantitative analysis, is ideal for investigating fundamental questions in developmental biology involving cellular differentiation, growth control and morphogenesis. However, a reliable amniote model system that is amenable to the rigors of extended, high-resolution imaging and cell tracking has been lacking. To address this shortcoming, we produced a novel transgenic quail that ubiquitously...
The San Jacinto fault is one of the most active branches of the San Andreas system in southern CA, and it consists of multiple segments that exhibit considerably different properties and behaviors both at the surface and at depth. As such, it provides an excellent natural laboratory for studying the mechanics, architecture and evolutionary behavior of a young evolving plate boundary. The goal of this project is to provide improved quantitative understanding of brittle and...
Across a diversity of animals, male seminal fluid coagulates upon ejaculation to form a hardened structure known as a copulatory plug. Previous studies suggest that copulatory plugs evolved as a mechanism for males to impede remating by females, but detailed investigations into the time course over which plugs survive in the female’s reproductive tract are lacking. Here, we cross males from eight inbred strains to females from two inbred strains of house mice (Mus musculus...
University of Southern California7
Children's Hospital of Los Angeles1
University of Montana1
Natural History Museum of Los Angeles County1
University of Vermont1
University of Pittsburgh1
Southwest Fisheries Science Center1
University of Kansas Medical Center1
Smithsonian Conservation Biology Institute1
University of Victoria1