Science in Christian Perspective

BIOLOGY
Irving W. Knobloch

From: JASA 5 (September 1953): 13-14.

Spontaneous Generation - Concluded

In the last quarter of the eighteenth century, the work on oxygen apparently opened up the controversy regarding spontaneous generation since flasks boiled and sealed were apt to be low in this important respiratory gas. In 1836 Schultz passed air into flasks after a passage over sulphuric acid but his cultures sometimes spoiled. Theodor Schwann, co-founder of the cell theory also tried his hand at solving the riddle. He passed his air through red-hot tubes. However, his work could not always be duplicated with sugar infusions. Schr6der and von Dusch invented the cotton plug and thus made their contribution to the -problem' Generally their cultures remained sterile but not in' variably with milk or meat preparations. Also, it was argued, cotton was a plant tissue and it deprived any possible organisms of needed oxygen.

In 1859 Felix Archimede Pouchet, Director of the Museum at Rouen, France published a large work on spontaneous generation purporting to prove its probability. His crucial experiment was as follows-

He sealed a flask of boiling water, inverted it over a mercury bath and thrust the neck of the bottle under the mercury. He broke the neck of the bottle under the mercury and connected it with an apparatus which, when heated, produced oxygen. The gas bubbled in and displaced the water. When half full of gas and half full of water, he took a piece of hay which had been heated and, with sterilized forceps, pushed it underneath the mercury and into the mouth of the bottle. The hay floated in the water. After a few days, the infusion was found to be full of small organisms' Triumphantly Pouchet asked where this evidence of life could have come from-not from the hot waternot from the heated hay-not from the oxygen which had been produced artificially?

Louis Pasteur was intrigued by Pouchet's claim and, over the objections of his friends, entered the fray. He felt that Pouchet was wrong but how to prove it! His task was to make a fool-proof experiment, one avoiding the criticism of the work of Spallanzani, Needham, Schultz, Schwann, Schr6der and von Dusch. First of all, he confirmed the discovery of Helmholtz (1843) that the air contained solid contaminants. He soon found that dust caused spoilage because it was the carrier of micro-organisms. Pasteur's classic experiment then was to put yeast broth into flasks, draw out the neck into the shape of a swan's neck, heat the flasks the proper time and then allow them to cool slowly. Of course the dip in, the neck "caught" the dust and with it, the bacteria. His flasks remained sterile. Pasteur did many other experiments all related to this topic and all leading to the same general conclusion. In presenting his findings to the world however, it was necessary to dispose of his rival, Pouchet, once and for -all. This he did by disclosing the errors in Pouchet's experiment described above. He threw a powerful beam of light on the mercury which was used and showed the dust particles thereon. Pouchet had, of course, pushed some of this dust (with the attending bacteria) into the flasks.

The Englishman, John Tyndall, played a "Huxley" to Pasteur by devising such an elaborate experiment that the critics of the Frenchman were silenced. Tyndall set forth his results in 1876, twelve years after Pasteur's great experiment and the details of the experiment will not be recounted here as they are well known. It should be stated that Tyndall was never able to detect living organisms arising from non-living matter. The question of spontaneous generation has not been seriously raised since the time of Tyndall.

Evolution is not connected directly with the origin of life. Biologists affirm their belief in some type of evolution but they profess ignorance of how life first started. It is quite an anachronism that while scientists disbelieve in spontaneous generation yet they cling to a physico-chemical theory which, in actuality, is very little different from spontaneous generation. In closing this short summary of the story of spontaneous generation, it is only fair to point out that in the story of creation, God Himself changed inorganic matter into organic. This was deliberate however and not quite the same as spontaneous generation.

Phylogenetic Trees

One of the pleasant pastimes of the last half of the nineteenth and first half of the twentieth century has been the construction of family trees. These arborescent or shrubby creations purport to show phylum relationships and derivations. If one assumes the evolution of large groups into other groups, they serve, no doubt, a useful purpose. Lately, however, there have appeared in the literature some startling statements which will be quoted without comment. It might be said that some scientists, at least, are becoming less naive and more realistic.

"All views which have been expressed concerning the phylogenetic interrelationships of plant families are largely a matter of personal opinion. To the authors, as indeed to many other botanists, it appears highly improbable that the families of flowering plants-have been evolved from one another. Those that agree with each other taxonomically in many respects may well have had a

common ancestry, but it seems fundamentally misleading to arrange them in a single, linear, phylogenetic series even if this has the form of a branched tree."-Frorn "Anatomy of the Dicotyledons"-C. R. Metcalfe and L. Chalk, Clarendon Press, Oxford, 1950.

"The Evolutionary tree proves to be not a tree at all but a profusely-branched shrub."-W. PauliThe World of Life-Houghton Miffle Co., 1949.

"A, phyletic tree so often resembles less a trunk with branches than a bundle of sticks."-I. Manton -Problems of Cytology and Evolution in the Pteridophyta. University Press, Cambridge, 1950.