Sharif, Sorry, I didn't mean to imply I thought we were as isolated from the natural world as some may think. But we would be hard pressed to deny that many in the so-called First World hardly come into contact with the natural world; I mean contact in the full sense of the word in this context.
For example, the flu shot is quite common in the USA (I abstain), are there any evolutionary repercussions to avoiding the flu? And I do not mean the obvious: what happens when there are no more flu shots; I am curious if and how having the flu (or not) effects evolution. Perhaps even our pursuit of reducing cold symptoms, or even avoiding the common cold, could have an effect. I have not seen any data on this or read any relevant studies (can that be my sig line?) but it occurred to me that we do many things without considering the long-term ramifications. Again, a book I read might have put this notion in my head: Why Things Bite Back: Technology and the Revenge of Unintended Consequences by Edward Tenner. David I have not seen any data or read any relevant studies on the subject... -----Original Message----- From: Ecological Society of America: grants, jobs, news [mailto:[EMAIL PROTECTED] On Behalf Of Sharif Branham Sent: Thursday, February 16, 2006 12:36 PM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: Regarding natural selection pressures on humans I dont think that we are as isolated from the natural world as we think. The field of zoonotics is all about how diseases pass from animals to humans. The recent concerns over avian flu, and West Nle virus show how much we are still very much tied to the natural world. ----Original Message Follows---- From: Dave Thomson <[EMAIL PROTECTED]> Reply-To: Dave Thomson <[EMAIL PROTECTED]> To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Re: Regarding natural selection pressures on humans Date: Thu, 16 Feb 2006 10:50:06 -0800 Very interesting post Andy, I have had an interest in the impact of modern medicine on the human population since reading Medical Nemesis by Ivan Illich long ago, although it is not something that I study as a scientist. That book might be of interest to you since it discusses (in great detail as I recall) the influence of modern medicine upon humans. I still remember how surprised I was that Illich found no evidence that immunology had a significant effect upon the course of a disease epidemic until Smallpox! And he concluded that Public Works (sanitation, etc.) has had a great positive (that value judgment open for discussion) influence on human health. I wonder about the consequences of limiting the influence of the so-called natural population stressors (aside from the obvious overpopulation problem). How important are these stressors to our evolution? For example are we, as a population, becoming more isolated from the natural world and are there consequences for this 'choice' we have made? David -----Original Message----- From: Ecological Society of America: grants, jobs, news [mailto:[EMAIL PROTECTED] On Behalf Of Andy Dyer Sent: Thursday, February 16, 2006 9:47 AM To: ECOLOG-L@LISTSERV.UMD.EDU Subject: Regarding natural selection pressures on humans Last spring, my advanced ecology class went to a local cemetery that has been in continuous use since 1847. We collected about 600 data points (death year, age at death) then generated a survival curve for male, female, before 1940 and after 1950. I avoided WWII to try to look in a broad sense at the eras before modern medicine and with modern medicine. =20 The <1940 results for male and female were identical, linear, and exactly fit a Type II survival curve suggesting that, before WWII, humans were equally susceptible to mortality-inducing factors (of which there were many) regardless of age or gender. The flu epidemic of 1918 was obvious as was an event in 1902. The results switched to classic Type I curves for >1950 with distinct differences between genders. Survival through age 40 was identical and then the curves diverged with females hitting the 50% survival mark about 10 years later than males. I thought the results were rather remarkable and we will be collecting more data from this population. (I tried to send this graph to the list, but it was blocked.) =20 To me this implies that natural selection was a real part of life up to 1940. Since then, the picture becomes blurry, but I think it is safe to say that modern medicine is buffering the human population from strong selection of the kind we faced in the past. =20 By the way, when someone says, "In my day, we respected our elders" they probably aren't kidding. At age 75, both genders were at 10% survival for <1940, but are about 35% for men and 65% for women in the >1950 data. If you could find a 75 year old in 1930, you were looking at a survivor and it would have been a good idea to find out what their secret was. =20 Andy =20 =20 Andrew R. Dyer Asst. Professor of Ecology Dept. of Biology & Geology University of South Carolina Aiken 471 University Parkway Aiken, SC 29801 Vox 803-641-3443 Fax 803-641-3251 [EMAIL PROTECTED] =20
