Complex Traits

The New England Journal of Medicine has a series of articles up on the impact of new genomic techniques on medicine, specifically in the domain of pinpointing genetic markers which are correlated with increased risk of a particular disease. David Goldstein has a skeptical take up on the future returns of genomewide association studies, while Joel Hirschhorn is more hopeful. There is another review which takes a middle path, emphasizing the relatively marginal predictive power of many of the risk alleles, but suggesting that techniques and results are bound to improve. Probably the most…
Wings, Horns, and Butterfly Eyespots: How Do Complex Traits Evolve?: Complex traits require co-ordinated expression of many transcription factors and signaling pathways to guide their development. Creating a developmental program de novo would involve linking many genes one-by-one, requiring each mutation to drift into fixation, or to confer some selective advantage at every intermediate step in order to spread in the population. While this lengthy process is not completely unlikely, it could be circumvented with fewer steps by recruiting a top regulator of an already existing gene network, i…