27 September 2005

Plus ça change

The September 21 issue of the Journal of the American Medical Association recalls a feature from 1905, in which they reported on a study of the public understanding of science that appeared in the August 1905 issue of Popular Science Monthly. The report, by Prof. John M. Coulter, seems eerily familiar.
Matter describing scientific research that is now published in popular magazines and in newspapers is scant in amount, sensational in form and usually wide of the mark.

The usual method of presentation is through a middleman, a reporter, who presents the matter in a “popular way,” and in so doing makes misleading statements and almost entirely removes the scientific atmosphere.

The 1905 JAMA emphasizes the popular focus on practical results.
[Prof. Coulter] calls attention very pointedly to the common misconception of the practical nature of research. When a scientific man brings out a discovery which is of marked commercial value, the laity is apt to comment on the commendable transferal of the investigator’s energy from some useless laboratory experiments to a field of practical value. In this there is disregard of the fact that the so-called practical discovery is based on and is the result of, in many cases, years of laborious and patient study, which had been considered by the average layman pure waste of time.

How far we've come...

17 September 2005

Predictions by Darwin – IV – The Gene

[Note: Readers may wonder about the long delay between this post and the previous posts in the series. Before completing it, I encountered an article by Jacques Monod, mentioned below. Monod makes many of the same points that I intended when I began. Having been thus scooped, I felt it necessary to redo the post accordingly. It also grew sufficiently long that I decided to separate out this part to post first.]

In the previous posts in this series, I argued that the popular image of scientific prediction was too narrow, discussed predictions that were actually “retrodictions”, and identified a category of scientific predictions called “cross your fingers”. These were actually particular empirical issues raised by the theory, often critical to its validation or refutation, but remaining to be resolved. Thus, for example, Copernicus agreed with Aristotle that heliocentric motion would give rise to an apparent annual parallax – a shift in the apparent position of the stars as seen from opposite sides of the Earth’s orbit. The failure to see this parallax was a serious problem for Copernicus, but he explained it away by asserting that the stars must be much farther away than previously thought. This explanation was a problem for him, because many people were not comfortable with the celestial sphere (and, presumably, God) being so distant. But it was also a “cross your fingers” prediction. Eventually, someone should be able to make a sufficiently precise measurement to see parallax, which would confirm both heliocentric motion and the great distance of the stars.

With the increasing precision of measurements, failure to detect annual parallax became more frustrating. But as long as it was consistent with a great distance to the stars, it was still not evidence against heliocentrism. (Of course, had there been independent evidence that the stars were nearer, then it would have been a refutation.) As it happens, before parallaxes were detected, the observational effects of the Earth’s heliocentric motion were detected by James Bradley in the form of the aberration of starlight, in 1725. Bradley’s discovery was a prediction of the form “I should have thought of that” – an unexpected phenomenon for which the existing theory provides a satisfactory explanation. It wasn’t until 1838 that Friedrich Wilhelm Bessel detected the first annual parallax, in the apparent motion of the star 61 Cygni.

Broadly speaking, Darwin’s theory of common descent with modification by natural selection has the following basic elements: variation (of progeny), selection (by ecological fitness, sexual appeal, etc.), inheritance of varied characters (in the progeny of the selected progeny), and lots of time (over which selection pushes small variations to become large variations). Of these, I think the one that troubled Darwin most at the time, and yielded his most striking prediction, was inheritance.

As did most scientists of his time, Darwin accepted the blending theory of inheritance, which held that progeny merged the hereditary factors of their parents to form some intermediate characteristics. Thus, the child of a tall mother and short father would be intermediate in height, and would pass that intermediate height characteristic on to its children. This made Darwin’s model of descent with modification more difficult, as it implied that significant variations would be diluted away after a few generations. Indeed, this was the nub of a famous criticism of Origin of Species by Fleeming Jenkin. Jenkin was an engineer (famous for work on laying oceanic telegraph cables, and for inventing a variation on the cable car in which the cable carried the power for the motors). He was a business colleague and friend of Sir William Thompson, later Lord Kelvin, of whom more later.

A point that has subsequently been made by historians of science is that this criticism was particularly effective because people assumed that most characteristics varied continuously. Indeed, one reason why Mendel’s work on genetics did not get more notice at the time it was published was that it was felt that the discrete characteristics he studied (peas wrinkly or smooth, green or yellow) were not relevant to the continuous variations that were thought to be the most important. Ernst Mayr complains that even Jenkin should have appreciated discontinuous inheritance, because the example of significant variation that he used in his critique was children being born with six fingers. Surely, says Mayr in The Growth of Biological Thought (1982, Harvard University Press),
Darwin could have easily refuted Jenkin by pointing out that six-fingered individuals do not have children with five-and-a-half fingers and grandchildren with five-and-a-quarter fingers…

However, the strength of the presumption of continuous variation was such that it was only at the turn of the century, as part of the New Synthesis, that Mendel’s empirical work was used to establish the general fact of “particulate” inheritance, rather than blending.

Darwin himself was fully aware of the problem, and even talked about it in a letter to T. H. Huxley in 1857, cited by R. A. Fisher in his book The Genetical Theory of Natural Selection (1930, Oxford University Press; reprinted in M. Ridley (ed.), Evolution - An Oxford Reader):
Approaching the subject from the side which attracts me most, viz., inheritance, I have lately been inclined to speculate, very crudely and indistinctly, that propagation by true fertilization will turn out to be a sort of mixture, and not true fusion, of two distinct individuals, or rather of innumerable individuals, as each parent has its parents and ancestors. I can understand on no other view the way in which crossed forms go back to so large an extent to ancestral forms.

Darwin later attempted a particulate theory, called pangenesis, in his 1868 book Variation of Animals and Plants Under Domestication. What counts for the discussion here, though, is not the theory itself, but the fact that he clearly saw the need for it. That nature worked by particulate inheritance, rather than by blending inheritance, was a “cross your fingers” prediction that was not validated until the New Synthesis. It should be considered every bit as bold as Copernicus’ prediction of the great distance of the stars.

Jacques Monod makes this point R. Harre (ed.), Problems of Scientific Revolution (Oxford University Press); also reprinted in M. Ridley (ed.), Evolution - An Oxford Reader):
What Jenkin’s remarks called for was a theory of heredity by which inheritance would be essentially discrete, discontinuous, and ensured by units that could be transmitted from generation to generation without losing their somatogenic qualities. Such is the gene… [T]he selective theory of evolution as Darwin himself had stated it, required the discovery of Mendelian genetics, which of course, was made.

If it fits, a good theory or a good idea will always be much wider and much richer than even the inventor of the idea may know at his time. The theory may be judged precisely on this type of development, when more and more falls into its lap, even though it was not predictable that so much would come of it.

I will talk about other Darwinian predictions in the “cross your fingers” category in the next post.

14 September 2005

легкомысленная тяжба

Lest you think that frivolous lawsuits are a peculiar feature of American courts, MosNews reports that court proceedings for Marina Bai’s lawsuit against NASA have now begun.

Bai, an astrologer, claims that the Deep Impact mission (which collided a probe with the nucleus of a comet in order to analyze the resulting ejecta) affected her both personally and professionally.

Bai is demanding $300 million from NASA for psychological damages caused by the Deep Impact probe hitting the Tempel-1 comet, RIA-Novosti news agency reported. “The astrologist Marina Bai believes that NASA’s actions interfere with [her] spiritual and life values system, as well as with the elemental life of the cosmos, thus upsetting the balance of forces in the universe,” the lawsuit states.

Bai stressed that NASA had altered her horoscope by crashing the spacecraft into the comet. “It is obvious that elements of the comet’s orbit, and correspondingly the ephemeris, will change after the explosion, which interferes with my astrology work and distorts my horoscope,” she said earlier.

Somebody should warn JAXA, the Japan Aerospace Exploration Agency, whose Hayabusa mission is about to do the same thing to the asteroid Itokawa. Hayabusa is currently in position 20 km above the surface of the asteroid. JAXA hopes to blast enough material out of the primordial rock to be able to collect and return samples to Earth.

Job Opportunity

Part of my morning routine is to review the results of the various job search agents that I have trolling the standard databases. This morning, my Monster agent included amongst the jobs that fit my search criteria one entitled: "United States Supreme Court Justice".

OK, maybe I've set my sights too high, but I thought it would be worth checking out.

The ad was posted by a company called Accolo, which promises to forward serious candidates to President Bush and the Senate Judiciary Committee. They are seeking applicants with "[s]trength of character, historical perspective, rhetorical flair, and a willingness to stand on principle", who are attracted to "the opportunity of a lifetime as you mold the fundamental legal principles of the United States during a time of great volatility". Among the job's advantages: "The United States Federal Government offers competitive salary and benefits."

The highlight of the posting, though, is the advance look at the sort of interview questions that applicants will face. These include:

2. To find a justification for the right to privacy, I would start looking in:
• My bathroom
• Warren Burger's imagination
• The Bill of Rights
• My credit card company's database
• Cleveland

8. In general, my view on endangered species is that:
• Sufficient controls and legislation are in place
• Environmental legislation is in place but needs more enforcement
• We have a moderate risk of losing endangered species and that some additional legislation and controls need to be put in place
• There is a crisis affecting endangered species and that extreme action needs to be taken
• They're best in a white wine sauce with capers

16. To me, the expression "prior experience on the bench" primarily refers to:
• Weightlifting
• Being third string on the high-school basketball team
• Gym class
• Being a judge

17. Regarding religious freedom in the public schools, I believe public schools should:
• Be allowed to include religious topics, with respect for a student's right to abstain
• Discuss religious topics only if ALL major religions are discussed equally
• Decide as a school what level of religious content is appropriate
• Not reference religion in any way

If you are interested in the job, or want to refer some qualified candidate, you can start the process at the Accolo website. Good luck!

02 September 2005


I have been out of town and out of electronic contact, thanks to a trip to post-Katrina Broward County in Florida. I'm back now, and will resume posting after catching up on the news.