Science and worldviews (2009.8.3[Mon.])

 

The best method is certainly to introduce the experimental facts immediately after the comparative, so as to correlate them. In this way Comparative Embryology ceases to be a dictionary of existence or absence of organs at peculiar stage of development, and Experimental Embryology is no longer a chaotic jumble, but is capable of systematic treatment. The fact is that the two should not be separated; they are not different branches of science, but complementary methods of attacking one and the same subject.

In: An Introduction to Experimental Embryology
G. R. de Beer (1926)


I suppose I need to say something about the relationship between science and worldviews. As scientific research becomes more compartmentalized and minutely focused, many no doubt feel that it is difficult enough just to get people to understand their own results, let alone to develop some overarching perspective from them, and if they do foray into philosophy, it often turns into nothing more than a rehash of what others have noted more ably before. In the not so distant past, physicists such as Schrödinger and Pauli looked at the relationship between man and the universe, and the biologists Crick, Monod and Dobzhansky all spoke on this as well. Looking back a bit further, we see that developing worldviews was the very bread and butter of the natural historians, something that was reinforced for me by the following passage on animal coloration and camouflage from Alfred Russel Wallace's "Tropical Nature ":

And even now, with all our recently-acquired knowledge of this subject, who shall say that these old world views were not intrinsically and fundamentally sound; and that, although we now know that colour has "uses" in nature that we little dreamt of, yet the relation of those colours - or rather the various rays of light - to our sense and emotions, amy not be another, and perhaps more important use which they subserve in the great system of the universe?

    If you think about it detachedly, it doesn't seem we need to go seeking such expanded roles or deeper meanings. As a research subject, color is just color, an attribute of some animal population's skin pattern subject to selective pressures and serving some adaptive function within a given set of environmental and ecological conditions. That in itself is sufficiently deep, and an interesting enough subject of study. I don't see the need to extrapolate it out to the universe as a whole. But, there is a but. For certainly one can begin to generalize and broaden one's field of view, to the principles that must be at work here: how developmental modules encoded in genetic networks might become targets of selection, or how to describe vividly the way in which a new morphological pattern might come into being. (Although admittedly, these begin to sound like the verbiage in a grant application.) This might not take us all the way back to the beginning of time, but I suppose there is scope to embrace, say, all of biological evolution. Even so, we remain reluctant to take on the universe entire without putting at least a bit of academic distance between. Perhaps it is a sad thing, but for better or worse, today's scientists have their feet firmly on the ground. But I for one think we need to translate more than just texts written for the lowest common denominator of understanding. If I can be forgiven a bit of hyperbole, I would say that science and its disciplines are the work of living, breathing humans who confront the mysteries of the universe. The worldviews first espoused by the great biologists of the 19th century certainly show that.

    In previous ages, living things were seen in theological as "Creatures" (the products of Creation), rungs on the ladder of the scala naturae that led up to the angels and God. It was Ernst Haeckel that introduced the alternate views of natural philosophy. Indeed, he intentionally sparked a global conflict between these conceptions of the world; in order to destroy one worldview, one must provide another, and a new Bible as well. Looking to the natural history of Goethe and Lamarck for his models, he developed a unified philosophy based in Darwin’s science and Kant's ideas of pure understanding (reine Verstandbegriffe). His was a purely mechanistic stance on evolutionary history, with no place for religion or gods, and his "The Evolution of Man" truly serves as a kind of bible of the scientific views he promulgated, which I believe he intended to supplant the Bible of the theological worldview. But, that fight ended much as the same as that of the Jacobins in the French Revolution.

    From Haeckel's own point of view, I am sure he was satisfied just to have refuted the remnants of Cuvier that were still being championed by Louis Agassiz. The advocates of evolution were clearly in the ascendant. But the latest critics of Haeckel are now scientists themselves, carried by a new scientific tide. One object of controversy is that the figures Haeckel used in "The Evolution of Man" are inaccurate. Undoubtedly thinking that no one would notice, he used identical plates multiple times, in one example to illustrate the embryos of dogs and humans and even a zygote. In the 90s, after Haeckel's death, Richardson showed that his figures of pharyngula-stage embryos were well off the mark. But I for one do not believe that this invalidates Haeckel's entire argument. In his defense, he himself wrote in the text that the appearance of the pharyngulas had been altered to illustrate his points. And though questions of what homology means and how to measure were left unresolved, the parts of the body that he identified as homologous certainly are so in terms of their morphologies. And that, I believe, is important.

    The more telling critique of Hacekel is rather directed at his own worldview, in which he famously proposed that ontogeny recapitulates phylogeny. "Die Entwicklungsmechanik " (Developmental Mechanics - a name I recall I saw here and there in Japanese Universities' reorganization days back in the '90s) by his disciple Wilhelm Roux held this up as a banner, and by the start of the 20th century morphology was waning as evidence-based experimental science gained ground. You could say that the furor over the plates in question was also symptomatic of this same struggle. The only person who seemed to take notice of this lamentable internecine strife was Gavin de Beer (Experimental Embryology, Oxford Univ. Press, 1926). We are finally seeing a New Synthesis of these approaches today, but what of Haeckel's worldview? In ancient times, most people's ways of understanding the universe were based on both science and religion. This was behind the struggle of natural history to realize itself as a science, and the birth pangs it experienced, which has been treated comprehensively in works such as Matsunaga Toshio's "The Struggle over Evolution on the Eve of Darwin" and Lynn Merril's "The Romance of Victorian Natural History".

    But just what is the scientific worldview that comes from embracing evolution? Although it is without precedent in human thought, it rendered untenable archetypal explanations derived from idealistic morphology, and the natural history that had been based in the recapitulation of developmental principles. It stormed the field, demanding a new synthesis of developmental biology and (population) genetics. It seems that the proponents of evolution, from Thomas Huxley to today, have all tended to base their arguments solely on data, while Haeckel's views on the evolution of life have only been forced aside (with the exception of those like Richard Dawkins, who reject religion altogether). I cannot think of any who followed in the path of this pioneer. Perhaps the critiques that have been leveled at him arise at least in part from a sense of envy? Textbooks written since his time have all tended to follow similar styles. And even I, who am working to revive Haeckel's principles for the modern day, am guilty perhaps of this, an unwonted apostasy.