Cancer and Evolution

Now I really think highly of Nick Rowe of Worthwhile Canadian Initiative but one of his co-bloggers may have gone a bit off the edge. I just read a blog by Frances Woolley in the same blog and I beg to differ. Like my Harvard friends, the economists who step with limited if any knowledge into medicine and genetics, they off, to quote a friend from Cape Cod, "go shingling their roof in the fog", always a bit of a risk task.

So what is the issue. Woolley remarks on a Nature article which talks of cancer as some evolutionary new event. The Nature article states:

In industrialized societies, cancer is second only to cardiovascular disease as a cause of death. The history of this disorder has the potential to improve our understanding of disease prevention, aetiology, pathogenesis and treatment. A striking rarity of malignancies in ancient physical remains might indicate that cancer was rare in antiquity, and so poses questions about the role of carcinogenic environmental factors in modern societies. Although the rarity of cancer in antiquity remains undisputed, the first published histological diagnosis of cancer in an Egyptian mummy demonstrates that new evidence is still forthcoming.

One is driven to make two immediate observations:

First, trees get cancer, yes indeed they do, those large knobs on old trees are cancerous if we use the well accepted definition. The cells have lost their ability to die, apoptosis, they loose the ability to differentiate, and the cells look like cancer cells. Yet plants somehow do not allow the cancer to metastasize, perhaps because of lack of lymphatics and a different circulatory system.

Second, cancers as we know understand it (see Weinberg) is the result of pathways controlling cell growth breaking down due to errors in cell cycle replication or from exogenous factors change growth regulation. Also there is the genetic predisposition that causes several familial cancers. We now know enough about many cancers to have a good understanding of what causes it.

Woolley states:

Without disputing the authors' basic premise or conclusions, I wish to posit an alternative explanation: old people are useless...Women typically finish child bearing by 40 and child raising by 60 - sometimes much earlier. Sure, every so often someone tries to make middle-aged ladies feel good by writing some nice paper about the evolutionary value of grandmothers, but basically living past middle age contributes minimally to the number of surviving children and grandchildren one has, and from an evolutionary point of view, that's all that matters.

How in God's name one can state this without any basis goes beyond reason. It is nice to state that when a reproductive entity reaches the time at which it can no longer reproduce it should be expendable, and even more so expended, then we males may just keep going till our 90s and somehow extending Woolley's argument just rid the world of postmenopausal women! This is akin to the Modest Proposal suggesting the use of Irish children for food! Do the English really think this way. Perhaps we are focusing on the wrong border, I am after all some 75 miles south of the Canadian border, and I shudder to think of the fine women in my family, they after all made it to the 90s! What would the Queen think! And my wife is of Canadian ancestry, Nova Scotia! Yikes again, perhaps this is the Canadian Health Care plan, get rid of old women! We were never told of such. Perhaps those brains in Washington should have advised us or perhaps it is really in the health care plan after all.

She continues:

Moreover, I have offered no empirical support whatsoever for the hypothesis that cancer has evolutionary value...Indeed, this is the fatal attraction of socio-biology - it's too easy to come up with untestable explanations for just about anything.

Here again I am aghast! She offers no evidence, self admitted. No evidence indeed, since the evidence to the contrary is all over if only one would engage a book. Then an attack on Wilson. You see, socio-biology is based on facts, and again, having somewhat lived through those attack, see the merit of the final remark baseless and in line with many of the others.

So, perhaps we should build that fence to the north, let the moose through, they are rather friendly folks, but beware those Canadians, those wild ideas, why just think where they may lead!