Hi Lactose intolerance is definitely unevenly distributed across different populations, as Beth indicates. Here are some statistics and maps showing its distribution.
http://www.foodreactions.org/intolerance/lactose/prevalence.html The level of lactose intolerance (in modern times at least) is quite low for UK (presumably Caucasians?), which leads one to wonder about its a priori probability as a disorder for Darwin. The story in Africa is more complicated because lactose tolerance appears to have evolved in parts of East Africa independent of its evolution in Europe. See: http://darwinstudents.blogspot.com/2009/02/evolution-of-lactose-tolerance.html I've also seen other sites arguing for the fairly rapid evolution of lactose tolerance once milk is introduced, but I'm not sure where. So incidence statistics may vary across generations. I talk about this and a number of other genetic determined disorders that vary across ethnicity (e.g., sickle cell anemia) in my culture and psychology class. Students appear more receptive to genetic explanations for physical disorders than for psychological traits, in part perhaps because the mechanisms for some physical disorders are well understood. It also allows one to make the point that genetic does NOT equal immutable, perhaps another factor in student resistance to genetic hypotheses. Take care Jim James M. Clark Professor of Psychology 204-786-9757 204-774-4134 Fax j.cl...@uwinnipeg.ca >>> Beth Benoit <beth.ben...@gmail.com> 17-Dec-09 4:32:30 PM >>> People who have bowel problems such as Crohn's, colitis and inflammatory bowel disease, are often also lactose intolerant, at least in my own and many family members' experience. Lactose intolerance is also a lot more common in the world than many realize. (Asians, Africans, African-Americans and Native Americans are almost 100% lactose intolerant, and worldwide, about 75% of adults are unable to tolerate lactose.) So lactose intolerance could have been just one of the many intestinal problems that poor Darwin endured. He was probably encouraged to drink milk to "settle his stomach," as my poor grandmother was urged to do. She had bleeding ulcers, but it was before lactose intolerance was understood, and she was encouraged to drink milk all day to soothe her tortured stomach. It's a marvel she lived as long as she did, albeit with most of her stomach removed and lots of other things as well... Secondly, we don't have to stick to just one disease to explain his skin problems. They don't *have* to be explained by the same disorder that caused his bowel problems. Beth Benoit Granite State College Plymouth State University New Hampshire On Thu, Dec 17, 2009 at 3:34 PM, <sbl...@ubishops.ca> wrote: > On 16 Dec 2009 at 11:40, Allen Esterson wrote, concerning my > complaint that a new article by Hayman (2009) on Darwin's > affliction didn't consider the previous "most recent" paper on the > topic in 2005: > > > Stephen has missed (vacationing?) what I find the most likely > > explanation, cited on TIPS on 5 October this year: > > > > "Darwin's illness: a final diagnosis" (2007) > > Fernando Orrego and Carlos Quintana > > Notes and Records of the Royal Society 2007: 61, 23-29 > > > > http://rsnr.royalsocietypublishing.org/content/61/1/23.full.pdf+html > > Yes, I was rash to assert that without checking. > > As it happens, I was startled and pleased to receive an e-mail > yesterday from none other than John Hayman himself, which > once again should remind us that our postings are public. Dr. > Hayman also pointed out that there have been a number of > other recent diagnoses, including a "resurgence of Crohn's > disease and mercury poisoning...and Helicobacter". > > He told me that the original version of his paper did address the > lactose intolerance theory, but was cut from the paper due to > space limitation. He sent me a copy of his views on the lactose > question, possibly the material edited out from his article, and > while he seems to agree that the lactose (or milk protein) > intolerance theory does have merit, it fails to adequately explain > "the severity and range of his symptoms". > > As for Allen's nomination of the Orrego and Quintana hypothesis > of Crohn's disease as "most likely", I'm not so sure. O & Q > argue that the precipitating circumstance was a bacterial > infection contracted in Chile. But both Campbell and Mathews > (2005) and Hayman (2009) argue that there were signs of the > illness before Darwin set sail. That would seem to rule it out, or > at least O & Q's version. > > Stephen > > ----------------------------------------------------------------- > Stephen L. Black, Ph.D. > Professor of Psychology, Emeritus > Bishop's University > e-mail: sbl...@ubishops.ca > 2600 College St. > Sherbrooke QC J1M 1Z7 > Canada > ----------------------------------------------------------------------- > > --- > To make changes to your subscription contact: > > Bill Southerly (bsouthe...@frostburg.edu) > --- To make changes to your subscription contact: Bill Southerly (bsouthe...@frostburg.edu) --- To make changes to your subscription contact: Bill Southerly (bsouthe...@frostburg.edu)
