The genome of the sea urchin Strongylocentrotus purpuratus

We report the sequence and analysis of the 814-megabase genome of the sea urchin Strongylocentrotus purpuratus, a model for developmental and systems biology. The sequencing strategy combined whole-genome shotgun and bacterial artificial chromosome (BAC) sequences. This use of BAC clones, aided by a pooling strategy, overcame difficulties associated with high heterozygosity of the genome. The genome encodes about 23,300 genes, including many previously thought to be vertebrate innovations or known only outside the deuterostomes. This echinoderm genome provides an evolutionary outgroup for the chordates and yields insights into the evolution of deuterostomes

Does ignorance promote norm compliance?

Recently, there has been progress in understanding the underlying mechanisms of normative behavior. Altruistic punishment can solve the second order collective good problem of norm enforcement. However, the problem to detect norm violators has been overlooked in most recent advances. We combine ideas from labeling theory and social constructionism in a mathematical model and analyze the interaction between subjective beliefs about the dark field of norm violations on one hand and actual norm violations and control behavior on the other. We derive an inverse self fulfilling prophecy effect: If inspectors or norm targets believe in a large unknown extent of norm violations, actual norm violations typically decrease. Finally, we provide an experimental design to test our analytical results