Science in Christian Perspective

BIOLOGY
Irving W. Knobloch

Spontaneous Generation

Some surprise may be caused by the title of our first offering because the view is held by most people that abiogenesis is non-controversial having been done to death by Louis Pasteur and John Tyndall. To say flatly, however, that organisms never arise de novo is a universal negative and can never really be proven. Abiogenesis is therefore not a dead issue, in fact, it was revived a short time ago when the bio-chemical nature of the viruses was being studied for the first time.

It might prove instructive to review some of the history of this question.

Although Aristotle had some fairly modern ideas about reproduction, he still believed that "some plants -are of spontaneous growth-some animals are produced from animals of similar form, the origin of others is spontaneous-." Lucretius followed in the same vein "And many living creatures even now spring out of the earth taking form by rains and the heat of the sun". Virgil gives his formula for generating bees from the fermenting moisture "growing warm in the softened bones".

In Judges 14: verses 5 to 8, one will find the account of Samson killing a lion and "after a time-he turned aside to see the carcass of the lion: and, behold, there was a swarm of bees and honey in the carease of the lion". This might he interpreted by some to mean that Samson thought that the bees were spontaneously generated in the lion. The quotation does not say this, however, and, in my opinion, the Bible cannot be accused of being "unscientific" in this case.

All of these incidents occurred in the dim past. In 1652, however, Van Helmont, a renowned physician and plant physiologist, insisted that rats came from a pot of wheat and a dirty shirt (note that shirt must be dirty) after about twenty-one days. Alexander Ross had worms originating in cheese and timber, beetles and wasps in cow dung and mice from the mud of the Nile.

The only discernible ray of hope comes from a statement in Homer's Iliad where we note that Achilles was afraid lest flies enter the wounds of the dead Patroclus and breed worms therein. Whether this observation was original or not, we cannot say, but it formed a spur which led to the overthrow of many ancient ideas on the origin of living forms.

This statement by Homer was read by Francisco Redi and it started a train of thought in his mind which had great consequences. Redi set about devising what has been described as the first controlled experiment, an event from which our modern scientific methods have developed. Redi made a hypothesis as follows-"and although it be a matter of daily observation that infinite numbers of worms are produced in dead bodies and decayed plants, I feel, I say, inclined to believe that these worms are all generated by insemination and that the putrified matter in which they are found has no other office than that of serving as a place, or suitable nest, where animals deposit their eggs at the breeding season-I assert that nothing is ever generated therein."

Having written this, he made a series of experiments to gather some data. He had two sets of jars of meat, one he covered with gauze and the other he left open. In the covered jar, maggots never developed and he reasoned correctly, that flies had not been able to enter and lay their eggs in the meat. One set of jars served a control for the other set and the only variable factor was the material covering the jar.

There are two other aspects to Redi's work which are not usually stressed. One is that the meat spoiled in the covered jars as well as in the uncovered ones. Redi apparently thought little of this since bacteria were not discovered until about eight years later by Leeuwenhoek (1676). In fact wonderment as to the origin of the bacteria did not become noticeable for several decades.

The second point which needs emphasizing is that one may be quite ingenious and intelligent about some things and yet have mental blocks about others. Redi disproved the spontaneous generation of worms in meat but, strangely enough, he still held that gall flies were spontaneously generated.

When the intelligentsia conceded the natural origin of the visible forms of life, they turned their attention to the origin of the unseen organisms. Here we can learn another lesson about science activities: the entire field of bacteriology marked time until the microscope was invented and improved. This same principle holds true in other fields. Scientific advance continually demands more and better tools.

In the eighteenth century the controversy about spontaneous generation became heated, to say the least, with an English priest, Needham, and an Italian priest, Spallanzani, furnishing most of the fire. To avoid boring my readers, we will briefly state that Needham was unable to prevent the growth of microorganisms (thus proving their spontaneous generation, in his mind) mainly because of faulty techniques. Spallanzani showed that proper heating and proper stoppering of flasks would preserve them indefinitely. He also confounded Needham by proving that the ,'vegetative force" in the flasks was not destroyed by the long boiling. Sterile, boiled flasks could and did develop growth if they were exposed to the air!

In the concluding portion of this history, we shall recount the battle of wits between Pouchet and Pasteur which highlighted the scientific portion of the nine teenth century.