De novo evolution of macroscopic multicellularity.

While early multicellular lineages necessarily started out as relatively simple groups of cells, little is known about how they became Darwinian entities capable of sustained multicellular evolution. Here we investigate this with a multicellularity long-term evolution experiment, selecting for larger group size in the snowflake yeast (Saccharomyces cerevisiae) model system. Given the historical importance of oxygen limitation, our ongoing experiment consists of three metabolic treatments-anaerobic, obligately aerobic and mixotrophic yeast.

Nuptial gift chemistry reveals convergent evolution correlated with antagonism in mating systems of harvestmen (Arachnida, Opiliones).

Nuptial gifts are material donations given from male to female before or during copulation and are subject to sexual selection in a wide variety of taxa. The harvestman genus has emerged as a model system for understanding the evolution of reproductive morphology and behavior, as transitions between solicitous and antagonistic modes of courtship have occurred multiple times within the lineage and are correlated with convergence in genital morphology. We analyzed the free amino acid content of nuptial gift secretions from five species of using gas chromatography-mass spectrometry.

Variation in Mating Dynamics across Five Species of Leiobunine Harvestmen (Arachnida: Opliones).

The study of mating choices often focuses on correlates of traits to the overall outcome of a mating interaction. However, mating interactions can proceed through a series of stages, with opportunities for assessment at each stage. We compared whether male or female size predicted mating interaction outcome across several stages of mating in five species of North American leiobunine harvestmen (commonly known as daddy longlegs).