|Section 3: Quotations from Scientists|
Marvels Defy Theory
Theodosium Dobzhansky, "Biological Adaptation," Scientific Monthly, vol. 55, 1942, p. 399.
...For it seems that each of these systems is balanced so delicately that it can function only as such--intermediate systems combining the features of the two would be absurdly incoherent and unfit to survive.
G.G. Simpson, This View of Life (Harcourt, Brace & World, New York, 1964), pp. 18-19).
...the origin of such an organ as the eye, for example, entirely at random seems almost infinitely improbable.
Ernst Mayr, Animal Species and Evolution (Harvard University Press, Cambridge, Mass., 1963), p. 604.
The analysis of the origin of new structures is still in its beginning. The arthropods, in particular, are rich in structures the history of which is still quite obscure. How did the pockets for mites that are found in certain bees (Xylocopa) and wasps evolve? The auxiliary structures that are often needed to facilitate aberrant behavior patterns in reproduction, such as secondary genital openings in the females of various groups of insects and various receptacles for sperm, are particularly difficult to explain.
Maurice J. Caullery, Parasitism and Symbiosis, translation by M. Lysaght (Sidgewick and Jackson, Ltd., London, 1952), pp. 252-253.
It has been apparent from the mass of data presented in the preceding pages, very much abbreviated in form and by no means exhaustive that symbiosis between the Metazoa and the lower plants, fungi or bacteria, extends over a very fast field and often raises very complex experimental problems. In general, this symbiosis exists under conditions that are strictly limited. In numerous cases it occurs in a specialized organ, the mycetome, formed from particular cells, the mycetocytes, and this organ develops by a series of equally well-defined processes. There, we find adaptations whose origin poses, as is always the case, problems of extreme difficulty. What has brought about the establishment and permanence of these associations which have become characteristic of the organism concerned, and are as precise and stable in their final structure and morphogenesis as the other elements concerned in the structure of the species?
The symbionts in each species are clearly defined; even the number of mycetocytes is fixed. There are some insects, as Buchner recognized, which possess two or even several species of symbionts. The respective propositions of these species are constant, the numbers of mycetocytes corresponding to each of them being fixed. The host organism appears as a precise regulating mechanism of symbiosis, capable in certain cases of eliminating the symbionts at a definite time by expulsion or by lysis[decomposition].
Edward S. Deevey, Jr., Yale Review, vol. 61, Summer 1967, pp. 634-635.
Deep sea squids and fishes are two of many kinds of animals that light their own way through the depths, and some have their lights arranged to focus through special lenses, ahead of the eyes. But the light-producing means are not all alike; some are glands belonging to the animals, while others are passive housings for luminous microbes.
Among the more attractive castes of worker ants, the honeypots are worth special attention. Their bodies are almost indefinitely elastic. The other ants hang them from the roof of the storeroom, stuff them with liquid food all summer, and make them disgorge, on demand, all winter. Or some other commoisseurs prefer the caste of carpenter ants called janitors, whose huge, conical heads, flat-topped and barky in texture, neatly plug the circular entrance-hole in the tree, but withdraw when appropriately tickled.
...Finally there was a New Zealand bird called the huia, which presumably foraged in pairs. The male chiseled the hole with his short bill, and the female used her long, curved one to extract the grub.
In a tropical rain forest, any crevice that can hold rainwater becomes a tiny pond, populated by a wildly improbable crew, mainly of insect larvae. The internodes of bamboo, if bored through by a worm, collect such ponds, and one kind of female mosquito hovers outside, when gravid, and fires her eggs with force and accuracy through the wormhole.
One could go on and one, discoursing on carnivorous plants, or bonmbardier beetles (which eject a noxious spray, powered by a small charge of high explosive), or bat ultra-sonar, or the diabolical life cycles of flukes and tapeworms, or the chemistry of sex-attracting odors. Of course these things are marvels, and of course, the fossil record being what it is, no one can say with confidence exactly how any one of them came about. ...
Stephen Jay Gould, "The Return of Hopeful Monsters," Natural History, Vol. 86, June-July 1977, p. 28.
On the isolated island of Mauritius...two genera of boid snakes...share a feature present in no other terrestrial vertebrate: the maxilliary bone of the upper jaw is split into front and rear halves, connected by a movable joint. In 1970, my friend Tom Frazzetta published a paper...(American Naturalist, vol. 104). He considered every preadaptive possibility he could imagine and rejected them in favor of discontinuous transition. How can a jawbone be half broken?
Carl L. Wilson and Walter E. Loomis, Botany (Holt, Rinehart and Winston, Inc., New York, 1957), p. 226.
Pollination in Yucca. The relationship between the Pronuba moth and the pollination of the flowers of the yucca plant is as extraordinary as to be unbelievable if it had not been verified repeatedly by qualified investigators since its discovery in 1892.
The yuccas are a group of some thirty species of lily-like plants with long, sword-shaped leaves... Most are native to the arid parts of the Southwest and Mexico... In the early summer the plant sends up a tall, coarse flower stalk bearing numerous large, white, drooping, bell-shaped flowers. The stamens, six in number, are much shorter than the pistil and also arch away from it, so that self-pollination is impossible. The style is short, and the stigma is three-lobed, with a deep chamber lying between the lobes.
In the evening, after the flowers open, the silvery white Pronuba moths, about 5/8 inch long, appear in the vicinity. The moths may come from a distance, attracted by the wind-borne fragrance. Both male and female Pronuba moths take no food and live only 2 to 5 days after mating. The males and female meet within the flower and mate. The female then places herself at the tip of a stamen, where she scrapes pollen from the anther by means of highly modified mouth parts. Visits to several stames produce a large amount of pollen, which is kneaded into a ball held just under the moth's head. The female then flies to another plant and, after boring a hole in the soft tissues of the ovary, deposits an egg in the vicinity of the ovules.
As soon as the egg is laid, the female moves to the top of the pistil and pushes a portion of her load of pollen into the stigmatic changer, pressing it down firmly with several vigorous thrusts. Another egg is then deposited within the same ovary, and again a portion of the pollen mass is forced into the stigmatic chamber. The depositing of each egg is followed by pollination, until about five eggs have been laid.
The eggs hatch into larvae, which feed upon the seeds which have developed from the ovules. The larvae mature in about a month, bore holes in the wall of the mature ovary (capsule), and drop to the ground. When the yucca flowers again, the insects appear above the ground as winged adults and the cycle is repeated.
The pollen which the female Pronuba has placed upon the stigma insures a supply of food for the larva when it emerges from the egg. Without pollination, the ovules would not develop into seeds with their stores of readily available food. The yucca, in turn, would be unable to reproduce without the Pronuba. Each larva eats relatively few seeds, perhaps eighteen to twenty-five, and the several hundred sound seeds which remain in each fruit allow reproduction to continue.
It is difficult to avoid the conclusion that the moth behaves intelligently and purposefully in this curious relationship, perceiving in advance that her labors result in food for her young. A more rational point of view regards this relationship as the result of a long evolutionary development, in the course of which the floral structure and the mouth parts of the insect have all become modified from a simpler condition. In whatever manner the flower and the insect became mutually adapted, it is now certain that one could not exist without the other.
[Note: The author makes no effort to give a detailed description of how evolution could have produced this adaptation. He suggests that adaptation by evolution is a view "more rational" than that of intelligence in insects, but makes no mention of the most rational view, that of the intelligent special creation of both moth and yucca.]
Henry N. Andrews, Jr., Ancient Plants and the World They Live In (Comstock Publishing Co. Inc., Ithaca, N.Y., 1947), p. 141.
Some of these flower-insect "co-operatives are, however, so incredibly complex in the way in which the everyday lives of the plants and insects have been integrated as to be more than bafflish to the student of evolution. However have so many flowers learned to mature their pollen before their stigmas are ready to receive it, thus preventing self-pollination of an individual flower? Why are they so careful to bend the stamens out of the way when they have shed their pollen and become useless, thus leaving the stigma free to accept the pollen from another flower that a visiting insect will bring? ...How have the orchids created such fantastic insect adaptations, in some species going to the extend of developing one petal to resemble the female of certain insects, thus luring the male to indulge in pseudocopulation and at the same time bringing about the pollination of the flower?
We can only wonder at these intricate yet purposeful spun webs of Nature's mosaic. They are problems that we are still a long way from solving.
Norman Macbeth, Darwin Retried (Gambit Inc., Boston, 1971), pp. 71-72.
In early summer the small Eumenes amedei of northern Africa and southern Europe emerges from the pupal strate as an elegant insect with yellow and black bands. Soon after mating, the female prepares a house in which her young can develop and sufficient food can be stored. She chooses an exposed and sunny situation on a rock or wall, and builds a circular fence of small stones and mortar, the mortar being made from dry flinty dust mixed with her own saliva. The stones are chosen with care, flint being preferred to limestone, and the fragments selected are all much the same size. Her choice of the most polished quartz fragments suggests (if we are anthropomorphic) that she is not indifferent to the esthetic effect of her handiwork. As the wall grows higher, the building slopes it toward the center and so makes a dome which, when finished is about the size of a small cherry. A hole is left at the top, and on this is built a funneled mouthpiece of cement.
The next task is to collect the food supply for the future grub. This consists of small caterpillars about half an inch long, palish green, and covered with white hairs. These caterpillars are partially paralyzed by the sting of the Eumenes and are unable to make any violent effort to escape. They are stored on the floor of the cell. Since they remain alive, they keep fresh until the grub is ready to eat them; if they were killed outright, their flesh would soon dry up or rot. When the cell is stocked, a single egg is laid in each house, and the mouthpiece at the top of the cell is closed with a cement plug, into which a pebble is set.
The egg is not laid upon or among the caterpillars, as in many allied species. These caterpillars are only partially paralyzed, and can still more their claws and champ their jaws. Should one of them feel the nibblings of the tiny grub, it might writhe about and injure the grub. Both the egg and the grub must be protected, and to this end the egg is suspended by a tiny thread of silk fastened to the roof. The caterpillars may wriggle and writhe, but they cannot come near it.
When the grub emerges from the egg, it devours its eggshell, then spins for itself a tiny silken ribbon-sheath in which it is enfolded tail-uppermost and with head hanging down. In this retreat it is suspended above the pile of living food. It lower itself far enough to nibble at the caterpillars. If they stir too violently, it can withdraw into its silken sheath, wait until the commotion has subsided, then descend again to its meal. As the grub grows in size and strength, it become bolder; the silken retreat is no longer required; it can venture down and live at its ease among the remains of its food.
The stone cells are not all stored with the same wealth of caterpillars. Some contain five and some ten. The young females, larger than the males, need twice as much food. But note that the cells are stocked before the eggs are laid, and that biologists generally believe that the sex is already determined when an egg is laid. How does the Eumenes know the future sex of her eggs? How is it that she never makes a mistake?
Robert M. Macnab, "Bacterial Motility and Chemotaxis: the Molecular biology of a Behavioral System," CRC Critical Reviews in Biochemistry, vol. 138, Dec. 1978, pp. 332-333.
These findings constitute an impressive increase in our knowledge of bacterial motility and taxis, but the subject is still very far from being fully understood. ...The existence of a rotary motor in bacteria, while interesting (and deflating to man's ego), need not involve any novel biological principles. ...
As a final comment, one can only marvel at the intricacy, in a simple bacterium, of the total motor and sensory system which has been the subject of this review and remark that our concept of evolution by selective advantage must surely be an oversimplification. What advantage could derive, for example, from a "preflagellum"(meaning a subset of its components), and yet what is the probability of "simultaneous" development of the organelle at a level where it becomes advantageous?
D.H. Offner, "The Space Toggle," Mechanical Engineering, Jan. 1980, p. 28 (in introduction to a technical study of the wing mechanism of flies).
To provide an engineering-type context, imagine or assume that the biological systems that constitute nature are the products of a designer. Furthermore, since these products are found everywhere, appear to be interdependent, and indicate a design sophistication of a high order, a more descriptive title for this designer might be Grand Omni Designer, easily remembered by the acronym, GOD. A logical corollary to this assumption is to consider nature as an acronym representing the phrase numerous activities that underline ruler's existence. This will provide a useful way to recall one view of nature--a word widely used in the literature of the natural sciences but often in an abstract or anthropomorphic sense. ...