An Evolutionary Link between Cancer and Scleroderma: Somatic Cell Variation and Selection

Geneticists have recognized for some time that many genes exhibit pleiotropy, meaning that one mutation can manifest in two or more distinguishable phenotypic effects. In a fascinating study recently published in Science [2014 Jan 10;343(6167):152-7. doi:10.1126/science.1246886], Joseph et al. offer evidence for an example of pleiotropy in which the distinct phenotypic effects associated with mutation of the POLR3A gene, which encodes a subunit (RPC1) of RNA polymerase III, are associated with two different diseases: one or another form of cancer and an autoimmune disease (scleroderma). (more…)

Intelligent Design, the Resurfacing of a Pseudo-Theory

In the past six months, I have encountered a review, by Thomas Nagel in The New York Review of Books (2012), of Alvin Plantinga’s latest book (Where the Conflict Really Lies: Science, Religion, and Naturalism, 2011 ) and a review, by Alvin Plantinga in The New Republic (2012), of Thomas Nagel’s latest book (Mind and Cosmos: Why the Materialist Neo-Darwinian Conception of Nature is Almost Certainly False, 2012).  Both authors are regarded as distinguished philosophers.  In their respective books, they both criticize what may be called the materialist neo-Darwinian approach to explaining life.  Plantinga and Nagel both discuss as a putative alternative to evolutionary explanations, the framework known as intelligent design (ID).  Whereas Plantinga appears to support ID, Nagel does not endorse ID but criticizes proponents of evolution for being overly disparaging of ID theorists. (more…)

Potential Influence of Winner-Take-All Markets on Human Evolution and Medicine

In the book, The Winner-Take-All Society (1995), Robet H. Frank and Philip J. Cook discuss a hypothetical scenario in which a new genetic technique allows babies to be engineered so that they have a 99% chance of performing 15% better on the standardized tests used in American college admissions, such as the Scholastic Aptitude Test (SAT) without actually being smarter in other contexts.  In 1% of babies so engineered, a severe emotional disability will result.  Frank and Cook speculate that many parents would be willing to risk the odds that an enginnered child would not be among the 1% of offspring who suffer the ontogenetic costs of the procedure.  They further argue that as more people exploit this genetic modification, the emotional pressure on the hold-outs would increase.  (more…)

Genetic Origins of Common Human Diseases

In the April 16, 2010, issue of Cell Jon McClellan and Mary-Claire King published a commentary that addressed the nature of the genetic variation that accounts for common human diseases, an issue of profound importance in evolutionary medicine.  The authors also address some methodological aspects of current research in this domain.  Their forceful critique of genome-wide association studies (GWAS) has elicited two spirited responses from investigators who have been active in GWAS (Klein et al., 2010, Wang et al., 2010). (more…)

Behind Blue Eyes

Eye color phenotypes  (from Eiburg et al. 2008)

Perhaps the main lesson we eventually learn in school is how little we actually know. In elementary genetics, we were taught that there are two alleles for eye color, blue and brown, with brown dominant, allowing simple assessment of whether we were more likely fathered by dad or the mailman. In these simple Mendelian days, eye color was not considered to be a focus for natural selection, except perhaps in the context of an associated trait, pale skin, being favored to help accrue vitamin D in the high, dark latitudes of northern Europe. Only over the past few months has a series of publications begun to reveal the true complexities of human eye-color genetics, genomics, selection and evolution. In the context of tantalizing data linking eye color to social behavior, rather than just skin and hair color, these studies show that the metaphor of eyes as windows to souls may be more than poetic. (more…)