http://www.columbia.edu/cu/alumni/Magazine/Winter2009-10/feature3.html

http://www.slate.com/id/2223745/pagenum/all/

In the absence of other evidence, one would suspect a celiac condition would either be neutral to overall fitness, or perhaps slightly negative as in the scenario you pose, but not negative enough to overcome massive environmental shifts that trigger manifestation of chronic diseases.

I will point out that there is a third “selective” scenario too, which is that the predisposition toward celiac coincidentally co-varies with a trait that is being positively selected for in the population (who knows, maybe celiacs are more fertile :-)

More confounding still — and this is the part that most life-science folks don’t understand — is that evolution is multi-scale and in particular culture and biology coevolve. But culture can evolve much faster than biology and so if you look at the system as a whole and admit to the reality that celiac is a condition that involved both biological and cultural factors (i.e. whether you eat a lot of wheat is a culture thing), then the evolutionary pace of the overall system doesn’t strain credulity at all.

One of the hottest topics in systems biology and evolutionary development is known as facilitated variation (or sometimes the Baldwin Effect), which essentially marries genetics adaptation with non-genetic adaptation (e.g. cultural evolution).

Ann: At this point scientist have no idea, however it is clear based on studies that the uptick is clearly environmentally driven.

Rafe:: how can u b be sure genetic drift is not at play in Celiac (& autism & other diseases…)? http://is.gd/2mUxb

Ann:: With your understanding of GD, do U think GD could explain a 4 fold increase over 60 years?

While it seems unlikely that that the fourfold increase could be explained by genetic drift (or even selective pressure) in under three generations, it is possible due to non-linear threshold effects. In other words, the predisposition towards celiac drifts (or is co-selected for) over many generations and then manifests itself due to a drastic environmental change, such as near total degeneration of the food supply in the last 60 years.

In the absence of other evidence, one would suspect a celiac condition would either be neutral to overall fitness, or perhaps slightly negative as in the scenario you pose, but not negative enough to overcome massive environmental shifts that trigger manifestation of chronic diseases.

I will point out that there is a third “selective” scenario too, which is that the predisposition toward celiac coincidentally co-varies with a trait that is being positively selected for in the population (who knows, maybe celiacs are more fertile :-)

More confounding still — and this is the part that most life-science folks don’t understand — is that evolution is multi-scale and in particular culture and biology coevolve. But culture can evolve much faster than biology and so if you look at the system as a whole and admit to the reality that celiac is a condition that involved both biological and cultural factors (i.e. whether you eat a lot of wheat is a culture thing), then the evolutionary pace of the overall system doesn’t strain credulity at all.

One of the hottest topics in systems biology and evolutionary development is known as facilitated variation (or sometimes the Baldwin Effect), which essentially marries genetics adaptation with non-genetic adaptation (e.g. cultural evolution).