The story of life: critical insights from evolutionary biology.

The notion that humans, in all their complexity, are merely an evolutionary accident, an insignificant speck in a boundless cosmos, is deeply unsatisfying for most nonscientists and fails to resonate with their life experience. What, then, can evolutionary biology ultimately tell us about the meaning of our lives? In conversation with Steve Paulson, executive producer and host of To the Best of Our Knowledge, paleoanthropologists Melanie Lee Chang and Ian Tattersall, and paleontologist Simon Conway Morris share their insights on these competing concepts and explain how meaning and purpose can be gleaned from the remarkable story of life itself.

Large-scale SNP genotyping with canine buccal swab DNA.

The dog is an attractive model for genetic studies of complex disease. With drafts of the canine genome complete, a large number of single-nucleotide polymorphisms (SNPs) that are potentially useful for gene-mapping studies and empirical estimations of canine diversity and linkage disequilibrium (LD) are now available. Unfortunately, most canine SNPs remain uncharacterized, and the amount and quality of DNA available from population-based samples are limited. We assessed how these real-world challenges influence automated SNP genotyping methods such as Illumina's GoldenGate assay. We examined 384 SNPs on canine chromosome 9 and successfully genotyped a minimum of 217 and a maximum of 275 SNPs using buccal swab samples for 181 dogs (86 beagles, 76 border collies, and 15 Australian shepherds). Call rates per SNP and sample averaged 97%, with reproducibility within and between analyses averaging 98%. The majority of these SNPs were polymorphic across all 3 breeds. We observed extensive LD, albeit less than reported for surveys using fewer dogs, consistent between breeds. Analyses of population substructure indicated that beagles are distinct from border collies and Australian shepherds. These results demonstrate the suitability of amplified canine buccal samples for high-throughput multiplex genotyping and confirm extensive LD in the dog.