A new (but old) Intelligent Design paper

Panda’s Thumb recently had an item about the strange case of the ISCID’s list of papers supporting Intelligent Design. Strange, because the ISCID won’t publicly release the details of the papers (i.e. “we have lots of evidence, but we can’t tell you what it is”). Could it be that, like another such list once touted by the Discovery Institute, they don’t actually provide much evidence for intelligent design? Nah, surely not.

Anyway, I’ve just found another paper which should be added to the ISCID list - not least because it gives ID a pedigree of hundreds of years. It was published in 1710 in the world’s first scientific journal, The Philosophical Transactions of the Royal Society. I found out about this paper in Bryan Sykes’ book “Adam’s Curse” which is about the Y-chromosome responsible for gender determination in mammals - having a Y-chromosome makes you a male. The paper is:

An argument for Divine Providence, taken from the constant Regularity observed in the Births of both sexes. By Dr. John Arbuthnott, Physician in Ordinary to Her Majesty [Queen Anne], and Fellow of the College of Physicians and the Royal Society.

Arbuthnott was investigating the relative numbers of men and women:

Among innumerable Footsteps of Divine Providence to be found in the Works of Nature, there is a very remarkable one to be observed in the exact balance that is maintained, between the number of Men and Women; for by this means it is provided that the Species may never fail, nor perish, since every Male may have its Female, and of a proportionable Age. The Equality of Males and Females is not the Effect of Chance but Divine Providence, working for a good End, which I thus demonstrate.

Arbuthnott showed that the number of males born was actually somewhat greater than the number of females born, by a factor of about 1.06, and gave a plausible reason for this excess:

… we must observe that the external Accidents to which are Males subject (who must seek their Food with danger) do make a great havock of them, and that this loss exceeds far that of the other sex, occasioned by Diseases incident to it, as Experience convinces us. To repair that Loss, provident Nature, by the Disposal of its wise creator, brings forth more Males than Females, and that in almost a constant proportion.

Arbuthnott was correct when he said that this proportion was not the result of chance. He was wrong, however, when he attributed it to Divine Providence. We now know that natural selection can explain this effect very nicely. There are genetic factors which affect the proportions of girls and boys born. If the number of one gender is too great, having children of the opposite gender then becomes a good way to increase your chance of leaving descendants, and genes favoring that gender will therefore be selected for. These selective forces cause the ratio of boys and girls born to stabilize at the point where the number of adult males and females is almost equal.

Arbuthnott can be forgiven for this error, given that the science of genetics and the theory of natural selection still lay far in the future. Still, I think the ISCID should add this paper to their bibliography; it’s probably at least as convincing as most of the other papers in there as evidence of intelligent design.