Birds and Flight

Recently I flew to London on the new Boeing 787 Dreamliner. Despite what media hype might lead a Dreamliner passenger to expect, there were no fires on board and the experience wasn’t particularly different from what I’ve experienced on innumerable other flights. From my perspective, the seats were too small, too close together and too hard. That is not to say that there were not some differences, the larger windows are a nice touch, they gave a disturbingly good view of the plane’s rather swoopy wings.

To understand why the Dreamliner is such a revolutionary aircraft requires looking below the skin. From the outside it appears to be a relatively normal aircraft with the usual number of wings and jet engines, a long tubular body, vertical tail and horizontal stabilizer. The differences between the Dreamliner and other aircraft involve the materials used – abundant carbon fiber instead of aluminum – the use of electrical rather than hydraulic systems to move the control surfaces and the method of producing, distributing and assembling components of the aircraft. Of course, there are many other differences when you get into the details, notably in the jet engines that make them more efficient, but the point is that without careful examination, the Dreamliner could easily be mistaken for a variation on normal aircraft rather than something truly revolutionary.

Something similar could be said of hummingbirds. On first inspection they look like fairly ordinary if somewhat small birds, with two wings, a tail, feathers, a beak and so on. But hummingbirds are revolutionary birds because they have differences built into their anatomy that allow them to move their wings in ways that other birds are incapable of. These differences allow them to hover like a helicopter and fly in any direction. This is no mean feat, as the developers of the Hawker Harrier jump jet and the Marine’s version of the F-35 Lightning aircraft have discovered. Just as it is not possible to go from a regular F-35, the Air Force F-35A or the Naval F-35C, to the Marine’s hovering F-35B, in small incremental steps, achieving the specific adaptations evident in hummingbirds using small incremental steps appears problematic.[1]

This is a significant problem if one is to account for the origin of hummingbirds via the mutation/selection mechanism of Darwinism. It was Darwin himself who pointed out in Chapter VI of the Origin of Species that, “If it could be demonstrated that any complex organ existed, which could not possibly have been formed by numerous, successive, slight modifications, my theory would absolutely break down.” Darwin went on to add: “But I can find out no such case." At the molecular level, many examples have been proposed appearing to fit Darwin’s criterion for the “break down” of his theory, but Darwin cannot have been expected to be aware of these. Various attempts have been made by Darwinists to address these challenges (sometimes coupled with shrill denunciations of the ignorance of those who suggest they may be a problem for materialistic Darwinism).

Like irreducibly complex molecular systems, the package of adaptations that allow hummingbirds exceptional flying abilities challenges Darwinism, particularly if the Darwinian requirement that each incremental change somehow increase the fitness of the intermediates is kept in mind. Hummingbirds are unique among vertebrates in that the way in which they use their wings is similar to the way in which hovering insects – such as bees – use their wings. Instead of a wing skeleton composed primarily of humerus (upper arm), radius and ulna (lower arm) bones with the wrist and hand bones forming a minority of the wing, in hummingbirds a large portion of the wing is composed of fused wrist and hand bones. The shoulder joint is modified to allow the usual up and down motion of a wing as well as a greater degree of twisting. This appears to be a large part of the secret to hummingbirds’ insect-like flight in which both up and down strokes of the wing provide lift. This modified wing and shoulder combined with pectoral muscles composed almost exclusively of type I fibers, which allow prolonged exertion (typically at the expense of speed in other organisms, but apparently not in hummingbirds), a reconfiguration of tendon attachment that allows very short muscle contractions to move the wing through its entire stroke, a brain to coordinate things and numerous other adaptations and presto, hummingbirds can buzz through the air like bumblebees.

When it comes to the origin of hummingbirds, it isn’t as if fanciful stories can’t be devised in which many imaginary intermediates satisfy the materialistic obligation to keep any Creator out of the plot. However, there are good reasons that some stories are more convincing than others. Most rational people choose brilliant engineers as a reasonable explanation for Boeing 787 Dreamliners and F-35B fighters, particularly those features representing a quantum leap ahead of other current aircraft. This is because, universally in the human experience, quantum leaps in technology have involved brilliant minds devising solutions to specific problems that they were seeking a solution to.

To take Louis Pasteur slightly out of context, “Le hasard ne favorise que les esprits préparés” (Chance favors only the prepared mind).[2] When chance events occur, they do not increase knowledge any more than they increase the function of engineered objects. Progress is made when chance events are observed by someone who then sees how what has been observed addresses something they are interested in and applies the new information. In other words, the observer must have a goal in mind for an observation to be useful, either in understanding something or finding a solution to a problem. Materialistic Darwinism rejects a priori involvement of any mind in creation of living things, let alone a “prepared mind,” so the quantum leap in design necessary for hummingbird’s reengineered wing and its complex movements can only be the result of unguided changes in the shape of bones, ligament attachment sites, behavior modification and so on.

The kind of adaptations that allow hummingbirds to hover or fly backwards would normally be explained as a product of design, just as the larger windows, novel production process and swoopy wings of a Dreamliner are. For philosophical reasons, materialistic Darwinism rejects this explanation. Is there other evidence of bird evolution that might support the assertion that hummingbird adaptations to their particular lifestyle evolved gradually via “numerous, successive, slight modifications?” Not really. In fact the evidence we have points in the opposite direction. Fossil hummingbirds, which are not common, are universally fully formed with the adaptations already in place that we associate with hummingbirds’ unique flying ability among vertebrates. This is why the few fossils that are available can be unambiguously identified as hummingbirds.

Intermediates with more generic bird species have not been found. The closest example is probably Eocypselus rowei, an excellent fossil found in the Eocene Green River Formation in Wyoming. The amazing thing about this particular fossil is that feather outlines are preserved allowing reconstruction of what its wings may have originally looked like. Because the wing has been reconstructed as intermediate between long slender swift wings and the relatively short wings of hummingbirds, it has been proposed as an ancestor of both modern bird types. It may be true that E. rowei had intermediate wings, but it is also true that it “shows neither modifications for the continuous gliding used by swifts nor modifications for the hovering flight style used by hummingbirds.”[3] This beautiful fossil actually does nothing to address the question of how hummingbirds or swifts developed their profoundly different yet equally amazing modes of flight.[4]

The absence of intermediates is emphasized by the discovery of a hummingbird fossil in Germany.[5] Humming birds are exclusively found in the Americas and were thought to have evolved there. Now we find a European specimen with all the hummingbird adaptations, thus no evidence of evolution. The hummingbird fossil record fits a commonly observed pattern of sudden appearance of fully formed organisms. This European hummingbird may be explained a number of different ways, but a common explanation would be that they came from ancestors who lived when America was not separate from Europe. That would put bird evolution, and particularly hummingbird evolution, way back in deep time. Where are the fossils?

Materialistic Darwinism demands that intermediates must have existed for which we have no record. In the case of hummingbirds, accepting this constraint becomes progressively more problematic as evidence accrues. There are good reasons to reject some explanations. For example, personal experience may lead us to expect sane mothers to reject “Mr. Nobody” as the true cause of the broken living room lamp following a rough and tumble indoor football match. Why accept “Mr. Nobody” as the explanation of where hummingbirds came from? Generally, rational people reject imaginary things because experience shows us that it is real causes in the real world that actually account for everything from aircraft to broken lamps. Why would this not be the case with hummingbirds?

We must be careful to not make too much of absent evidence – absence of evidence is not evidence of absence – but where evidence is absent, it must be acknowledged that conclusions are being drawn on the basis of something other than evidence. The basis of conclusions under these conditions may be drawn from philosophy, logic, theology, authorities or feelings. To the degree that these are accepted as reliable guides, they may influence what we believe to be true; but in the realm of science, it is empirical evidence that must form the basis of conclusions. Given the universal observation of where innovations in design originate, hummingbirds’ complex and integrated adaptations allowing modes of flight unique among birds probably didn’t arise via an unguided Darwinian mechanism, they probably were caused by the actions of a Designer. In other words, it is reasonable to draw the same conclusions about the cause of innovations in hummingbirds as we do about the cause of innovations in the Boeing Dreamliner or F-35B aircraft: brilliant engineering.


 

Timothy G. Standish, PhD

Geoscience Research Institute


Interested in more information about design in birds? Check out Illustra Media’s documentary, Flight: The genius of birds.


[1] For a discussions of some of the adaptations found in hummingbirds that make hovering flight possible, see: Hedrick TL. Tobalske BW. Ros IG. Warrick DR. Biewener AA. 2011. Morphological and kinematic basis of the hummingbird flight stroke: scaling of flight muscle transmission ratio. Proceedings of the Royal Society B. published online doi:10.1098/rspb.2011.2238.

[2] This statement of Pasteur’s is widely quoted. It comes from a lecture he gave at the University of Lille in 1854.

[3] Ksepka DT. Clarke JA. Nesbitt SJ. Kulp FB. Grande L. 2013. Fossil evidence of wing shape in a stem relative of swifts and hummingbirds (Aves, Pan-Apodiformes). Proceedings of the Royal Society B. 280(1761) doi:10.1098/rspb.2013.0580

[4] Swifts achieve level flight speeds over 110 km/h (around 70 mph) making them candidates for the fastest birds in level flight. Faster birds, such as peregrine falcons, achieve higher speeds with the aid of gravity when diving.

[5] Mayr G. 2004. Old world fossil record of modern-type hummingbirds. Science 304:861-864.