Evolution

Gene Expression

Category archives for Evolution

Quantitative genetics strikes back! (?)

The 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…

Be safe and live long

Arboreality has allowed for the evolution of increased longevity in mammals: The evolutionary theory of aging predicts that species will experience delayed senescence and increased longevity when rates of extrinsic mortality are reduced. It has long been recognized that birds and bats are characterized by lower rates of extrinsic mortality and greater longevities than nonvolant…

The IGF1 small dog haplotype is derived from Middle Eastern gray wolves: Background A selective sweep containing the insulin-like growth factor 1 (IGF1) gene is associated with size variation in domestic dogs. Intron 2 of IGF1 contains a SINE element and single nucleotide polymorphism (SNP) found in all small dog breeds that is almost entirely…

An interesting exchange in Nature on ways to conceptualize the evolution of virulence. First, Adaptation and the evolution of parasite virulence in a connected world: Adaptation is conventionally regarded as occurring at the level of the individual organism, where it functions to maximize the individual’s inclusive fitness…However, it has recently been argued that empirical studies…

To the left I’ve juxtaposed the images of the four Bushmen males whose genomes were analyzed in the recent Nature paper and compared to Desmond Tutu. I’ve added to the montage a photo of a Swedish and Chinese man. The Nature paper looked at the HapMap data sets which had within them whites from Utah,…

Lactase persistence results in the ability to break down the lactose sugar in milk as an adult, lactase being the enzyme which breaks down lactose. If one can not digest that sugar, and still consumes milk, then one exhibits the symptoms of lactose intolerance. Originally diagnosed as a disease it has come to light that…

The Others could travel by sea

One of the great things about science is that old orthodoxies regularly get overturned; it’s not a bug, it’s a feature. Of course the personal downside is that it means models which scholars have invested their lives and intellectual capital into may turn out to be unsupportable, but at the end of the day it’s…

One of the interesting aspects ensuing from the rise of molecular phylogenetics is that the trees are generally concordant in broad strokes with older research which was based on morphology. This is not too surprising, as nature does tend to show some intelligible patterns which can be cross-checked with different methods (e.g., the fact of…

Interesting that I just pointed to Neandertal DNA, a really big story just came out on ancient Greenlander genetics, Whole Genome of Ancient Human Is Decoded: The genome of a man who lived on the western coast of Greenland some 4,000 years ago has been decoded, thanks to the surprisingly good preservation of DNA in…

Charles Darwin was a genius (I think)

After watching Creation last week I decided to take the plunge and read Origin of Species. As I’ve mentioned before I did read Origin early in my teen years, but in hindsight with minimal comprehension. Since then I’ve occasionally started to read Origin, or perused an extract, but I’ve never made it from front to…