Craniofacial diversification in the domestic pigeon and the evolution of the avian skull.

A central question in evolutionary developmental biology is how highly conserved developmental systems can generate the remarkable phenotypic diversity observed among distantly related species. In part, this paradox reflects our limited knowledge about the potential for species to both respond to selection and generate novel variation. Consequently, the developmental links between small-scale microevolutionary variations within populations to larger macroevolutionary patterns among species remain unbridged.

Epistatic and combinatorial effects of pigmentary gene mutations in the domestic pigeon.

Understanding the molecular basis of phenotypic diversity is a critical challenge in biology, yet we know little about the mechanistic effects of different mutations and epistatic relationships among loci that contribute to complex traits. Pigmentation genetics offers a powerful model for identifying mutations underlying diversity and for determining how additional complexity emerges from interactions among loci. Centuries of artificial selection in domestic rock pigeons (Columba livia) have cultivated tremendous variation in plumage pigmentation through the combined effects of dozens of loci.

The utility of domestic dogs in assessing human morphological variation.

Although distantly related to us, dogs are a highly variable cohabitating taxon that may provide clues relevant to hypotheses of human variation, evolution, and development. Here we first propose the utility of domestic dogs as a heuristic model for the study of human variation and evolution. Next we provide a case study of variation in a mandibular relationship previously suggested to distinguish Neanderthals from modern humans taxonomically.

Contrasting evolutionary dynamics of the developmental regulator PAX9, among bats, with evidence for a novel post-transcriptional regulatory mechanism.

Morphological evolution can be the result of natural selection favoring modification of developmental signaling pathways. However, little is known about the genetic basis of such phenotypic diversity. Understanding these mechanisms is difficult for numerous reasons, yet studies in model organisms often provide clues about the major developmental pathways involved.

Population-scale analysis of human microsatellites reveals novel sources of exonic variation.

Using our microsatellite specific genotyping method, we analyzed tandem repeats, which are known to be highly variable with some recognized as biomarkers causative of disease, in over 500 individuals who were exon sequenced in a 1000 Genomes Project pilot study. We were able to genotype over 97% of the microsatellite loci in the targeted regions. A total of 25,115 variations were observed, including repeat length and single nucleotide polymorphisms, corresponding to an average of 45.