Quantitative Genetics
razib | February 27, 2010The Genetics of Human Adaptation: Hard Sweeps, Soft Sweeps, and Polygenic Adaptation:
There has long been interest in understanding the genetic basis of human adaptation. To what extent are phenotypic differences among human populations driven by natural selection? With the recent arrival of large genome-wide data sets on human variation, there is now unprecedented opportunity for progress on this type of question. Several lines of evidence argue for an important role of positive selection in shaping human variation and differences among populations. These include studies of comparative…
razib | September 1, 2009I have recently mentioned an analogy between the heritability of height & weight. That is, the proportion of variance of the trait which can be explained by variance in the genes. How closely do parents resemble offspring. A new paper in PLoS ONE, How Humans Differ from Other Animals in Their Levels of Morphological Variation, look at how this variation among human populations compares to other animals:
Animal species come in many shapes and sizes, as do the individuals and populations that make up each species. To us, humans might seem to show particularly high levels of morphological…
razib | February 24, 2009Wings, 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…