METAMORPHOSIS: THE WORLD OF BUTTERFLIES

adapted from an article by

Brian W. Grantham-Hill

B.Sc.

Used with the kind permission of the Creation Science Movement, 50 Brecon Avenue, Cosham, Portsmouth, England, P06 2AW.

What is the fascination of butterflies? To be sure, their colorful wing patterns are a major reason why people like butterflies, but they have other interesting features, as well.

In this pamphlet, we shall have a brief look at the intriguing world of butterflies. In the process, it should become apparent why it is very unlikely these magnificent creatures could have evolved.

Some Basic Facts

Butterflies, together with the duller moths, make up the order of Lepidoptera (“scale-winged”) - so-called because of the tiny, delicate scales on their wings. The often spectacular coloration of butterfly wings results from two factors: Pigment gives the earth tones (browns, orange, yellow, black, and white), and the 3-dimensional refractive effects of ridged scales produce their metallic and iridescent colours (bright blue, purple, green, silver, etc.). Butterflies have two pairs of wings. These are coupled by means of an overlap of the forewings and hind wings, enabling certain large butterflies to attain speeds of 15 m.p.h.

Three pairs of legs are connected to the central thorax, although the larvae may have additional prolegs and claspers not present in the adult. The blood system is “open” - viz., not channelled through veins. Not surprisingly, then, butterflies do not have lungs. Air is brought to the muscles and organs by tiny tubes (tracheae) that open onto the tough chitin (pronounced kye'-tin skin.

Butterflies are normally harmless to crops. Most adult butterflies, called imagoes (pronounced i-ma'-goes), ingest nectar from flowers using the complex suction muscles of their proboscises. A few species, however, dine on pollen, animal dung, or even sweat. When it comes to mating, some jungle species will defend their territory from pairs of the same or other species. Butterfly mating often takes place during flight.

The butterfly world includes some mimic species. Up to five different species having almost identical colouring may feed together on the same shrub, yet be incapable of interbreeding. One of them may be poisonous (e.g., the Monarch), so birds tend to leave the mimics (the Viceroy is a Monarch mimic) alone, too. Then there are the chromatic polymorphs: three or more individuals of the same species may look quite different from one another.

World Distribution

As fragile as butterflies appear to be, the superb design of these insects enables them to live all over the world. Australasia, with its many islands, boasts a wide variety of butterfly species. Perhaps most notable are the giant “birdwings.” The females have wingspans up to one foot and fly above the tree canopy of their tropical forest home when looking for a mate. The males of one birdwing species have I forewing sex patch that gives their metallic blue, green, orange, and black coloration a spectacular appearance.

Africa, south of the Sahara desert, is home to almost 1,500 brilliantly coloured kinds of butterflies, including huge swallowtails. Some are so rare that only a few specimens have ever been caught. Doubtless, not all tropical species have yet been identified.

The Americas have their share of beautiful and interesting butterflies, too. For example, there is the superb South American Owl butterfly, so called because it has spots like owl eyes on each wing. The Tiger swallowtail, with its splendid yellow and black coloration, is one of the more notable butterflies seen in North America.

Many species of butterfly are found throughout the diverse habitats of North America, Europe, and Siberia. Several varieties survive in the arctic tundra. They make use of the warming effects of the sun during the short summer, and overwinter in the larval stage at temperatures well below freezing. In the Alps, one can find butterflies flying above the snow line!

Migration

Some of the more than 15,000 known species of butterfly go on annual or seasonal migrations that take them across immense distances. Starting from their winter home in central Mexico, in the spring Monarch butterflies migrate as far as the north shore of Lake Superior, mating and laying eggs on milkweed food-plants along the way.

On the other side of the Atlantic, portions of the migratory Red Admiral and Painted Lady populations fly all the way to Iceland and Russia from North Africa - depositing eggs on nettles and thistles, their respective larval food-plants, en route.

Migrating butterflies show uncanny savvy. When traversing open water, they keep just above the surface for minimum wind resistance. When traveling north from Africa, the Painted Lady generally avoids extended flight over water, crossing at the Straits of the Gibraltar or traveling the Malta-Sicily-Italy or Crete-Greece corridors. More startling still, the progeny of these long-haul migrants return in autumn without their parents! How do they know which route to take? Surely in migration we see evidence of pre-programming by the Designer!

Metamorphosis and Symbiotic Relationships

In the tropics, the adult butterfly emerges between two and three weeks from the time the egg was laid. In cooler climes, the process slows to between two months and, for hibernating species, a year.

Over the course of its life, the butterfly undergoes a complete change in form and behaviour. From an egg it develops into a larva (the caterpillar), then into a pupa (the chrysalis), and finally into the imago (the adult). The illustration in Figure 1 depicts the dramatic difference between the caterpillar and the mature butterfly.

Butterflies exhibit some remarkable abilities. Somehow, butterflies know to lay their eggs on the type of plant the caterpillar can dine on when it hatches. The Silver-washed Fritillary goes one step further: she lays her eggs on tree bark near the food plant. Her young will descend in the spring to feast on violet leaves. Another amazing trait is seen in the larvae of the Troidini swallowtail of Australia. They can neutralize the poisonous acid of one particular plant family, allowing them to feed without competition from the larvae of moths or other kinds of butterflies.

After devouring its eggshell, a larva may grow to more than 1,000 times its original weight and shed its skin from four to eight times before pupating. The final shedding is usually accompanied by the production of silk, used to suspend the chrysalis from a host plant. A silken anchor pad is prepared for the pupa to grab onto with its special cremaster, and a sling is fashioned as a secondary support device.

The larvae of the Large Blue (Maculinea arion) develop in an entirely different way, living symbiotically in the nests of a species of red ant. Each tiny butterfly larva hatches from a single egg laid on a thyme plant. (It would eat its neighbours if they were handy, so eggs are instinctively laid one per plant.) The larva then feeds on the thyme plant for several weeks before it drops to the ground. There, it waits for a red ant to find it and stroke it. This stimulates the caterpillar to secrete drops of sweet honeydew, which the ant picks up and takes back to the nest for feeding to ant larvae. When the ant returns to the Blue, it finds the front segments puffed up. The ant grips the larva with its jaws and struggles off with it to the nest. Once in the ant nest, the Blue larva continues to produce honeydew for the ants, but in exchange devours some of the ant larvae! After a long winter, hibernation, and spring pupation, the adult Blue will crawl out of the ant nest and inflate its wings to get ready for flight and mating.

Pupation (the reorganizing chrysalis stage between larva and imago) usually takes about a week. During pupation, the body cells of the caterpillar break down and migrate to different points within the chrysalis to form the elements of the imago - the wings, the antennae, the coiled mouth-parts (proboscis), the reproductive organs, etc. During pupation, the wings develop in a collapsed condition, waiting for the air pressure in the abdomen to force blood into the tiny nervures when the butterfly emerges from its case. Once erect, the wings dry quickly, allowing the insect to fly almost as soon as it becomes visible to birds. The sex determines the pattern and colours of the two kinds of wings scales. One kind of scale reflects light like a mirror, helping to camouflage the butterfly; the other gives the beautiful wing patterns associated with different species.

Could Butterflies Have Evolved?

Evolution by random change is an absurd notion for a creature that undergoes such thorough and anatomical and morphological changes during its life as does the butterfly. How could the butterfly have evolved, either incrementally or in a single leap? This is something that the evolutionist cannot explain. Extinction would face any butterfly species that was not functioning perfectly at every stage in its metamorphosis. If at any point its anatomy, morphology, physiology, or behaviour was not as it should be, the butterfly would die. Not one species of butterfly can afford to be “experimental” in its development.

The means for detecting the correct food-plant for the laying of eggs is performed by a process unknown to science. But, without the correct food, the larvae would not survive. The enzymes that dissolve the body tissues of the caterpillar must only go so far or the creature would disappear in insect soup! With its cremaster, the pupating butterfly must grab onto its custom-made, silken anchor pad at just the right moment as the last shrivelled envelope of larval skin drops away. If the insect is not programmed to make this movement fast enough, it will fall to the ground and die.

The Blue is totally unable to complete its life-cycle outside an ant nest. An evolutionary explanation would require that the Blue butterfly, the thyme plant, and the ant evolve simultaneously, the symbiosis being maintained among all three at every stage of the evolutionary progression!

Consider the unusual forked head organ (osmeterium) possessed by the swallowtail caterpillar (see Figure 1). When the caterpillar senses danger, this organ pops in and out and an unpleasant odour is emitted. When confronted by these vigorous movements and the noxious smell, birds fly off to seek food elsewhere. Since osmeteria confer an advantage, why do not all species of butterflies develop them? Because no creature can cause his own body to produce a new piece of biological equipment. And why have swallowtails, with their advantageous osmeteria not supplanted all other species of butterflies? There are many species surviving perfectly well without this organ because each species has been adequately equipped for survival.

The marvel of the delicate yet fully functional design of the butterfly can only point to Designer. This conclusion condemns evolutionary dogma, which insists upon random genetic changes (mutations) improving the chance of a creature surviving and reproducing by increasing its biological complexity. As decades of laboratory irradiation of fruit flies has amply demonstrated, if mutations are not lethal, they are almost always harmful, and they never result in an increase in genetic information. Only in very rare instances might a mutation have survival value - such as when wingless insects are hatched on a wind-swept island that is not inhabited by insectivores. But the advantage comes from a deficiency in the organism. It never adds to the complexity of the creature in an evolutionary sense. In fact, such mutations leave a species less able to compete for survival with other insects or survive even a minor change in the particular environment that favours a given mutation.

Natural selection actually weeds out mutations that have not already caused the mutant organism to perish. Far from being a mechanism of evolutionary progress, natural selection is a means for preserving the continuity of a species!

Summary

The remarkable symbiotic relationships that butterflies have with plants and other insects, as well as the marvelous migratory habits exhibited by a number of their species, lead us to conclude that these colourful creatures must be the handiwork of God.

And most compelling of all is the amazing process of butterfly metamorphism, the origin of which defies an evolutionary explanation. It must have been ordained by the Creator. In fact, the metamorphosis of a humble, earthbound caterpillar into the exalted beauty of a butterfly aloft reminds us of the expectation of the Christian: “We shall not all sleep, but we shall all be changed” (1 Corinthians 15:51).