The Perfect Wing Stroke

What is the utility of a fourth or a fifth of a wing stroke? Could any insect or bird get by with a wing that is a fraction of its normal size? Could it serve its purpose working at a reduced capacity? These questions are a challenge for those who accept Darwinian gradualism and adaptation. According to the Darwinian evolution theory, biological traits arise by small genetic variations steadily modifying body structures that are subject to natural selection. The new traits are selected or eliminated in the struggle for survival and adaptation to the environment. In this context, a wing that is designed for flying and not fully formed or functional would not be helpful and natural selection would eliminate it.

A bird or an insect cannot fly with a fifth of a wing, or with the fifth of a wing stroke. Nevertheless, evolutionists want us to think that those structures evolved through multiple intermediate stages to the full size over a span of long evolutionary time. This claim raises two questions: Is there any case of intermediate forms in the fossil record of birds and insects? What would be the usefulness of an incompletely formed wing?

In the Darwinian model, beneficial mutations capable of producing full wings accumulated over millions of years through gradual stages, avoiding the forces of natural selection that tend to eliminate useless traits, and resulting in the fully formed wing structures we now see in birds and insects. If that were the case, we would expect to see multiple intermediate forms in the fossil record. However, that is not case.

Wings in the Fossil Record

Birds show up in the fossil record with fully formed wings for flight. The alleged intermediates—Dromeosaurids and Archaeropteryx—show a mixture of reptile and avian traits, and in fact are not good candidates for intermediate forms, because they show what paleontologists call mosaic morphology, in which the alleged lineage does not show a sequence of gradual changes, but discontinuities, reversals and out-of-sequence traits.[i]

Insect wings are a sophisticated trait that also appears abruptly in the fossil record without any ancestor with intermediate or transitional traits. Within the evolutionary timescale, insects with wings capable of flight appear in the fossil record in the Upper Carboniferous, some 320 million years ago. Fossils of wingless insects appear in the Silurian, supposedly some 80 million years before.[ii] No fossils have been found showing intermediate stages in the evolution from wingless forms to insects with wings. This raises the question of how it is possible that 80 million years of alleged evolution did not leave any record of transitional forms.

Modeling the Origin of Wings in Insects

A number of hypotheses have been proposed for the origin of wings in insects. In 1985, Kingsolver and Koehl[iii] evaluated two hypotheses that included adaptive factors that could have favored the transition from flightless insects to forms with wings capable of flight. These adaptive factors included aerodynamics (gliding and parachuting) and thermodynamics. Kingsolver and Koehl indicated that wings initially might have functioned as aerofoils for steady-state gliding that would allow insects to leap from the ground or trees and avoid predators. Alternatively, proto-wings might have developed as parachutes to slow the rate of descent of a falling insect, or as thermoregulatory structures to increase body temperatures by absorbing radiation, hence allowing more vigorous activity. After modeling for different shapes and sizes of insects, and experimenting with artificial models in an open circuit and jet wind tunnels, they concluded that none of those factors could be predicted as a driver for the evolution of insect wings. There are multiple uncertainties, including the ecological conditions in the past that could have affected the needs of insects, and the unknown climate conditions in the Devonian (was the climate cold and that drove the development of thermoregulation?).

Kingsolver and Koehl suggested that insect wings evolved from small, rudimentary structures that were pre-adapted (pre-programmed) with respect to flight. In other words, evolution was directional and had a purpose in the long term, developing some early structures that would later serve as flight organs, which in the meantime were serving other purposes. This idea is somehow contradictory with the assumption that mutations and natural selection are unguided, blind and purposeless forces of nature.[iv] Moreover, it is a poor explanation and indeed it does not solve the problem of lack of evidence for evolution of wings in insects. The lack of evidence for an idea is not solved with another idea for which there is also no supportive evidence.

Did Wings Evolve as ‘Pre-Adapted’ Structures?

The pre-adaptation or pre-programming idea is also embedded in other hypotheses for the origin of wings in insects. Consider, for example, the ‘fin theory’, the idea suggested by Bradley[v] and reviewed by Kukalova-Peck[vi] that pterygotes, a group of ancient primarily terrestrial arthropods[vii] became swimmers and over time increasingly adapted for excursions into the water. According to this theory, these primitive aquatic arthropods had small thoracic side lobes or protowings that later evolved into wings. Bradley suggested that “the little pro-wings which would have had little or no effect in air, could have been highly useful as fins and propulsion organs in water. In the process of using pro-wings as fins, the hinge and flight musculature began to develop.”[viii] He also suggested that pterygotes were probably capable of leaving the water for purposes of mating and dispersal.

What Do ‘Primitive’ Insects Show?

For this theory, Bradley presented fossil evidence: all primitive Paleozoic nymphs[ix] had articulated and movable winglets throughout their ontogenetic development.[x] Although he presents no evidence for it, he states that these winglets were used for a propelling function. According to Kukalova-Peck, it is “quite evident that use of the wings in some Paleozoic nymphs under aerial conditions was already decreasing. Thus, the wings in all terrestrial juvenile roaches were completely flightless. Some nymphal wings in Palaeodictyoptera, as judged by their general shape and position, were in the process of rapidly losing their ability to function. At the same time, aquatic ephemerid nymphs used their wings for promoting forward motion under water.”[xi] Here the author is saying that in the Paleozoic there were land nymphs with wings, which were gradually losing their functionality. As a result of this evolution, some land insects became flightless, and at the same time some aquatic arthropods began to use body lobes for promoting motion under water, which later developed into wings. This whole scenario is fictional and contradictory: first, wings in land insects; then reduction or loss of them; at the same time development of wings (for propelling) in aquatic arthropods; and finally gradual transition from water to land and development of wings in land insects again. Is there any evidence for each of the alleged steps? No. The only thing available is fossils of winged and wingless insects and other arthropods. But fossils per se do no show evolution. They only show what existed: both winged and wingless arthropods, in both aquatic and terrestrial environments.

Moreover, Kulakova-Peck’s model faces a very important problem: pterygotes, the alleged ancestor of winged insects, appear for the first time in the fossil record in rock layers above layers with winged insects.[xii] So they are out of sequence. The alleged ancestor appears after the diversified, supposedly descendant forms, a similar scenario as with birds. So to avoid having to explain the origin of wings twice, first in land insects, and then later in aquatic arthropods, evolutionists say that the evolution of pterygotes occurred considerably earlier, evolving the winged forms of insects and also persisting as wingless aquatic forms. Has anyone found fossil evidence for any such speculations? No evidence has been found in the fossil record for the alleged transitions from land to water and from water to land, just assumptions derived from the evolutionary theory.

Evolution Wants to Explain Everything

The idea that flight developed in land insects from aquatic ancestors lacks supportive fossil evidence other than isolated examples of both winged and wingless specimens. Adding more to the faulty reasoning, and following the usual evolutionist strategy, Kukalova-Peck adds that “Bradley’s hypothesis [the ‘fin theory’], even if it erroneously explains the origin of the wing itself, seems to somehow conform with the fossil evidence in the origin of flight.”[xiii] We have seen that the fossil record does not show evolution, it just shows what was there. Kulakova-Peck thinks that the fossil record might support an idea that nevertheless might be wrong for other reasons. The question is, what is then the value of the fossil record? Isn’t it supposed to show evidence for probable or against ideas? This is typical of materialistic reasoning: the assumptions, hypotheses or models are never questioned, because they know that evolution is true anyway, even if data signal the opposite.

Other speculations about the origin of wings in insects have been proposed, including the development of wings first as thoracic structures for courtship display in male insects,[xiv] or the development of both thoracic and abdominal segments of aquatic nymphs as structures used in ventilation and/or gas exchange.[xv] Again, there is no evidence for these ideas. They stem from the necessity to explain the origin of winged insects within a paradigm in which evolution from a common ancestor is assumed.

Evolution of Wings Does not Fly

The fossil record of insects shows sudden appearance of both flightless and flight capable insects, without any transitional forms. The fossil record shows species that show high complexity, both anatomically and physiologically, and fully adapted to the land or to the water, but no intermediate forms in either morphology or ecology. And even if there were intermediate forms, how would we know that they were evolutionary intermediates, and not just different ecological forms with no connections between them?

Kinsolver and Koehl acknowledged the problem that the fossil record poses for models of insect wing evolution, and they ask the question, “[w]hat are the characteristics of the stem-group for pterygotes [the alleged ancestors of winged insects] before the full development of wings and flight?”[xvi] In other words, what did the ancestors of winged insects look like? He answers that paleontologists think that in birds some species like Archaeopteryx might offer some hope in understanding the evolution history, but “the complete lack of such transitional insect fossils between the early Devonian and their Upper Carboniferous poses considerable problems for analogous studies of evolution of insect wings and flight.”[xvii] Here we surmise that both the evolutionary assumption of transitional forms and the time involved are wrong.

Raúl Esperante

Geoscience Research Institute

[i] For a review see T. Standish, Aves fósiles, Ciencia de los Orígenes 67(May 2004): 1-5; R. Esperante, ¿A dónde ha volado la secuencia evolutiva de los reptiles a las aves? Ciencia de los Orígenes, 68 (Autumn 2004):8-9.

[ii] Engel, M. and Grimaldi, D., 2004. New light shed on the oldest insect. Nature, 427: 627-630.

[iii] Kingsolver, J.G. and Koehl, M. 1985. Aerodynamics, thermoregulation, and the evolution of insect wings: differential scaling and evolutionary change. Evolution, 39(3):488-504.

[iv] Douglas J. Futyuma, in his book Evolution (Sinauer Associates, Sunderland, Connecticut, 2009), p. 282, states that “[Darwin's] alternative to intelligent design was design by the completely mindless process of natural selection, according to which organisms possessing variations that enhance survival or reproduction replace those less suitably endowed, which therefore survive or reproduce in lesser degree. This process cannot have a goal, any more than erosion has the goal of forming canyons, for the future cannot cause material events in the present. Thus the concepts of goals or purposes have no place in biology (or any other of the natural sciences), except in studies of human behavior.”

[v] Bradley, J. C. 1942 .The origin and significance of metamorphosis and wings among insects. Proc. VIII. Pan Amer. Sci. Congr., Biol. Sec., 3:303-309.

[vi] Kukalova‐Peck, J. 1978. Origin and evolution of insect wings and their relation to metamorphosis, as documented by the fossil record. Journal of Morphology, 156:53-125.

[vii] One of the most common representatives in the fossil record is Pterygotus, which was an ancient genus of large marine arthropods that included the sea scorpions. They had four pairs of walking legs, a pair of swimming paddles and a pair of large chelae (pincers) for capturing prey. These were fully developed, adapted marine organisms that show no evidence of transitioning from or to any other animal form.

[viii] Quoted in Kukalova‐Peck, p. 69.

[ix] Nymphs are immature forms of some invertebrates, including insects, which undergoes gradual metamorphosis before reaching its adult stage.

[x] Ontogenetic development (or ontogeny) is the process of development of an individual from conception, embryo, through the fetal stage through birth and growth to adult.

[xi] Kukalova-Peck, p. 70.

[xii] Kingsolver, J.G. and Koehl, M. (1994) Selective factors in the evolution of insect wings. Annual Review of Entomology, 39, 425-451. More specifically, in the geologic time scale pterygote insects (those aquatic arthropods with alleged proto-wings) appeared after insects like paleopterus and neopterus, which already had fully formed wings.

[xiii] Kukalova-Peck, p. 70, emphasis added.

[xiv] Alexander, R.D. and Brown Jr, W. (1962) Mating behavior and the origin of insect wings. Occasional Papers of the Museum of Zoology, University of Michigan, 628:1-19.

[xv] Kingsolver and Koehl, 1994.

[xvi] Kingsolver and Koehl, 1994, p. 429. Emphasis added.

[xvii] Ibid. Emphasis added.