Rapid Responses to:
|
|
Rapid Responses: Rapid Responses published:
-
![[Read Rapid Response]](/icons/misc/sectionDOWN.gif)
Your editing is faulty
- John N Burry (21 November 2003)
-
Even more on preventing skin cancer
- marco procopio (23 November 2003)
-
Re: Even more on preventing skin cancer
- John N Burry (11 February 2004)
|
|
|||
|
John N Burry, Retired PO Box 7177 Hutt St PO Adelaide South Australia 5000
Send response to journal:
|
Editor-My unedited response was as follows. Editor-I have just returned from a prolonged holiday in Europe where I experienced the heat wave and was conspicuous in my hat. Dr Procopio alleges that I wrote that people with black skin have been chosen to live in Australia because they are protected against skin cancer. I wrote that black people were chosen by natural selection to live in Australia but did not say why. Malthus pointed out that a limited amount of food restricts animal numbers therefore only a limited number could survive in what he termed the ‘struggle for existence’. Malthusian ‘struggle for existence’ gave Darwin the vital clue in the formation of his theory of natural selection following his voyage around the world in the Beagle between 1831 and 1836. Darwin wrote in his autobiography. "In October 1838, that is, fifteen months after I had begun my systematic enquiry, I happened to read for amusement Malthus on Population, and being well prepared to appreciate the struggle for existence which everywhere goes on, from the long-continued observation of the habits of animals and plants, it at once struck me that under these circumstances favourable variations would tend to be preserved, and unfavourable ones to be destroyed." Aboriginal Australians have succeeded in the struggle for existence for at least 60,000 years because they were able to hunt and gather. Aborigines would not have survived if their skins had not been black in Australia’s intense sunlight. Dr Procopio presumes that when Australian Aborigines arrived in Australia their skins were black already. It matters little what the colour of their skin was when they arrived, whether their skins were or became black. Australian conditions composed the Darwinian selective forces which ensured that they were fully protected against sunlight by their black skins, which Europeans who have been chosen by natural selection to live in Europe are not, when they live in Australia. Europeans in Europe depended upon food in their struggle for existence. Vitamin D was essential if they were to survive and it is reasonable to postulate that that accounts for the colour of their skin even although again we can not be certain what the colour of their skin was, when they arrived in Europe. John N. Burry, retired dermatologist
You edited Darwin's thought as he was on the way to formulating his theory of natural selection. Would it not have been wiser to check with me after the editing. No doubt a large number of your readers will recognize the error as the quotation is probably the best known Competing interests: None declared |
|||
|
|
|||
|
marco procopio, consultant psychiatrist Priory Clinic, 14-18 New Church Road, Hove, BN3 4FH
Send response to journal:
|
I apologise to bore most readers reiterating a concept which is already obvious to them, but I feel that it is important, for respect of the scientific method, to make a comment on Dr Burry's letter. Coloured people were not "chosen" by natural selection to live in Australia. There was no choice to be made. The ancestors of the present aborigeni were black men and women who slowly emigrated from Africa going East. No white man has reached Australia until the last few centuries. There was no selection or choice, black people arrived,no one else, that's it. If Dr Burry doubted that the ancestors of the Australian Aborigeni and European autoctonous populations were black populations who emigrated from Africa, he would find himself on his own claiming this in the modern scientific community and going against all the biological and archeological evidence available. Regarding the claim that aborigeni would have not survived, if they were not dark skinned, to the intense Australian sunlight, it is instead a well known fact that fair skin allows a better protection to heat than dark skin which absorbs sunlight and therefore heat. Black skin protects instead from melanoma, but, as already clarified in my previous letter, melanoma does not promote selection because starts too late in life to do so. To conclude: all our ancestors were black skinned, wherever we live. Some populations, this time through darwinian selection,have become lighter in skin. No selective pressure has made any specimen of Homo Sapiens darker, we were all black to start with. Competing interests: None declared |
|||
|
|
|||
|
John N Burry, Retired Dermatologist PO Box 7177 Hutt St PO Adelaide 5000 South Australia Australia
Send response to journal:
|
Editor--My letter (BMJ 2003; 326: 1148 (24 May)) states that emphasis on the biology of European existence in Australia “could be a most effective educational tool” to convince people to cover up and stay out of the sun to prevent skin cancer. That education along those lines is necessary is apparent from the statement in Procopio’s rapid response. I claimed that Aborigines could not have survived in Australia for 60,000 years if their skins had not been black otherwise they would not have been able to hunt and gather and that no matter what the colour of their skins when they arrived in Australia (something which could not be proven by scientific method to be beyond reasonable doubt in spite of the conventional wisdom) their skins were ultimately black because of Darwinian natural selection. Procopio states “Regarding the claim that Aborigines would have not survived, if they were not dark skinned, in the intense Australian sunlight, it is instead a well known fact that fair skin allows a better protection to heat than dark skin which absorbs sunlight and therefore heat.” The second law of thermodynamics does not work in that fashion when it comes to skin and the energy of ultraviolet light. There are few fair skinned people who have not suffered sunburn. Procopio’s mistaken conception may not be general because people know that they may be sunburned but is evidence enough that emphasis on the biology of European existence in Australia “could be a most effective educational tool.” By continuing to stir the pot my hope is that the BMJ may ask it experts to advance education in this field by a full length statement or debate if there is disagreement. Education is essential if the rate of cancer is to fall. Competing interests: None declared |
|||