The previous two blogs (here and here) have taken just two examples of things that Darwinian evolution cannot explain adequately. If you recall, the important thing to understand is that “evolving” is not just morphing into something more complex, more advanced, and better adapted as evolutionists would have you think. Evolution requires a genetic change to an organism but it can’t be too drastic of a change or else the organism would die. It must be the incremental build-up of infinitesimally small changes, genetic mutations, each of them beneficial to the organism. But even the overly simplified break down of the individual changes necessary to move from asexual to sexual reproduction or from a pigment cup eye to a pinhole eye show that this idea of evolution cannot produce those things. Evolutionists use the word “evolve” to just gloss over the finer details and interconnectedness of systems within an organism. This point is so powerfully stated by William Coleman in his book, Studies in the History of Biology:
“A major change, for example, a sharp increase in the heart beat or the diminution by half of the kidney and thus a reduction in renal secretion, would by itself have wrought havoc with the general constitution of the animal. In order that an animal might persist after a change of this magnitude it would be necessary that the other organs of the body be also proportionally modified. In other words, an organism must change en bloc or not at all. Only saltatory modification could occur, and this idea was to Cuvier (considered the father of paleontology), as it is to most modern zoologists but for very different reasons, unverified and basically absurd. Transmutation by the accumulation of alterations, great or small, would thus be impossible.”[i]
What he’s saying is that each change, though it appears slight and slowly moving the organism in the direction of evolutionary advancement, must be accompanied by many other changes in order for the organism to survive. Like we discussed last week, the addition of thousands of photoreceptors to a sight organ not suited for that many photoreceptors would not be advantageous, and would obviously wreak havoc on the functionality of that organ and the survivability of that organism.
So I want to take a closer look at another classic example cited by Darwinian evolutionists as “evidence” based on these two main premises: intermediate structures had to be advantageous and complex things must be slowly built up from something simple that has changed via micro-mutations. Let’s look at the feather. Evolutionists state that feathers evolved from a frayed reptilian scale. The first issue is there is no such thing as acquired characteristics. A physical change like that in the adult does not result in a genetic change for the offspring. A reptile fraying its scales from overuse or damage does not change the genes it will pass on to its offspring. The reptile offspring is still genetically programmed to have fully formed scales. So the frayed scale must actually be the result of a genetic mutation causing the scale to not fully form.
But that leads us to the next issue. The genetic mutation must provide the offspring some kind of advantage. Yet a reptile with a frayed scale provides no survival advantage. The whole point of progressing from scale to frayed scale to a feather is with the intention of providing the organism flight. But a frayed scale would be weak, easily deformed, and quite permeable to air. Things permeable to air would not be suitable for flight, or even for gliding. But at the same time, a frayed scale would not be suitable for climbing and grasping things. A reptile with a frayed scale would be less able to climb and scavenge for food, but it would be unable to fly. The frayed scale intermediate does not provide any survival advantage for the organism before it became suitable for flight. Therefore, it’s difficult to see how this creature with a frayed scale would have survived to pass this trait down to the rest of the population.
The third problem with this evolutionary scenario is it implies a feather is just a random tangle of frayed scale filaments. Instead the feather is actually considered to be the most complex integumentary structures found in vertebrates. The feather is ordered in an amazingly complex way to achieve a tightly intertwined, aerodynamic structure. It is not only used for flight but for thermal insulation and waterproofing.
There are two basic types of feathers found on a bird: vaned feathers (cover the exterior of the body) and down feathers (underneath the vaned feathers). A typical vaned feather has a main shaft called the rachis. At the base of the feather, the rachis expands to form the quill, which is a hollow tube without vanes, to insert into the skin. Fused onto that are a series of branches called barbs. Those are then further branched into barbules. The barbules then each have tiny hooks called barbicels for cross-attachment to the neighboring barbule. The down feather has a similar structure except it doesn’t have the barbicels. Therefore each barbule is free, or unattached, to the other barbule, which is what makes those feathers so fluffy. The purpose of that is the down feathers can trap air to provide thermal insulation for the bird. Even the shape of the feather is important to allow for different modes of flight. The position of feathers is maintained by an intricate system of tendons so they can open and close to improve flight efficiency. And the locations of these fibers and tendons is critical to the flight of the bird, either aligned in the middle of the feather for birds that fly, or towards the tips as they are in flightless birds.
So what would the incremental build-up of the feather be? Let’s assume there was a genetic mutation to an entire generation of reptiles resulting in their scales being frayed. Assuming they all survived, they produced offspring with a genetic mutation that the frayed scales would be more like the down feathers. How would that animal survive? It’s not a bird – it’s still a reptile but it has down feathers instead of scales, yet it can’t fly with only down feathers. The down feathers do not have the barbicels to give the feathers enough stiffness for flight. But there would be no point in having the barbicels present without the rachis. As you can see, though it seems so simple, the bird’s feather requires all of those structures in place before it can be used for flight.
Even if the reptile with frayed scales could survive and have just the right genetic mutations to develop feathers, it still has a problem. Just because an organism has feathers does not mean that it is ready for flight any more than a person with feathers glued to his arms means that he could safely jump off a cliff. There are still mathematical aerodynamic factors that determine if flight would even be possible. The wing area, body weight, and power of the organism must be factored in as well. Even in man-made machines for flight, there is a limit to the amount of weight that can be accommodated by the plane mechanics – which would be the plane wings, engine thrust, and weight of the vehicle. In the same way, the feathered organism must have enough power and lift in the wings to offset the weight of the animal.
So it’s not just the structure of the feather that must be in place before flight, but numerous other features that are necessary to fly. Although the feather is exceedingly light, the bird’s plumage actually weighs two or three times more than its skeleton. That is because the bird’s bones are hollow which helps to make flight possible. It also has the appropriate sizing of muscles and tendons that attach to those wings to make movement of them possible, all of which are unique for a flying vertebrate.
Furthermore, the bird has a completely unique lung system. In all other non-flying vertebrates, the air flow is bi-directional, moving back and forth into and out of the lungs. As a result, air coming into a mammal's lungs is mixed with 'old' air (air that has been in the lungs for a while). This 'mixed air' has less oxygen. Birds have unidirectional air flow so the air moving through the lungs is largely 'fresh' air and has a higher oxygen content. The unidirectional flow of air is maintained during both inspiration and expiration by a complex system of interconnected air sacs in the bird’s body which expand and contract in such a way so as to ensure a continuous delivery of air through the parabronchi. It allows the bird to be able to breathe at higher altitudes than other mammals. And this system also keeps the volume of air in the lung nearly constant. No lung in any other vertebrate species even comes close to the avian system. Yet this system is identical in all essential details in all birds - from hummingbirds, to ostriches, to hawks. This unique avian lung cannot function until the parabronchi system and the air sac system are both highly developed and able to function together in a perfectly integrated manner. It could not have slowly acquired this respiratory system by building up from our lung system type.
So not only do all the parts of the feather have to be together, perfectly matched, sized, and integrated to be used in flight, but the bird’s bones must be light-weight, the musculoskeletal system must be appropriately sized and fitted for wings, and the avian lung system must be fully functional.
Therefore, the classic Darwinian evolution example of birds evolving from reptile scales very clearly falls apart under the scrutiny of irreducibly complex mechanisms and viable intermediate organisms. The intermediate creature would be maladapted to survive its environment and therefore not a candidate for progressing the evolutionary chain.
Now I know what the evolutionists are going to say to this. What about the feathered dinosaurs? What about the Archaeopteryx? For those that aren’t familiar with these, the Yutyrannus huali, the “beautiful feathered tyrant,” was the largest yet found of the now famous Chinese “feathered dinosaurs.” The technical description published in Nature that a “gigantic feathered dinosaur from the Lower Cretaceous of China” was recovered. Within the article though, scientists qualified the “feathered” label: These “feathers” are actually just “feather-like features,” or “simple filaments.” Similarly, the Nature article described them as “filamentous integumentary [skin] structures.” Real bird feathers are complicated, with semi-hollow cores and branching barbs, but the fossil’s filaments apparently did not have these features. These Chinese tyrannosaur fibers, as with perhaps all the famous Chinese fossil dinosaur “feathers” so far, are more straightforwardly interpreted as the fossilized fragments of partly decayed skin.
As for the Archaeopteryx, many evolutionists consider it to be a bridge between reptiles and birds. This primitive bird did possess certain skeletal reptilian-like features – teeth, a long tail, and claws on its wings. But in one respect, flight, the Archaeopteryx was already truly bird. Its wings already had flight feathers as fully developed as any modern bird and capable of powered flight. Unlike dinosaurs, Archaeopteryx had a large braincase for the increased motor control and sensory input that were required for flight. Theropods (dinosaurs) had a lizard-like pelvis that was distinct from the birdlike frame of the Archaeopteryx. It already had a robust furcula (wishbone), a trait characteristic of strong fliers—one that keeps flight muscles from crushing the bird’s delicate internal air sacs. No evidence supports the story that such fully formed wings with fused clavicles “evolved from” the tiny, clavicle-free theropod forelimbs. Even claw measurements of the Archaeopteryx fall within the range of true perching birds. It was a bird without a single transitional feature.
So the “feathered dinosaur” is simply a reptile with decayed skin fibers. And the Archaeopteryx is really a fossilized bird. But there is no progression of reptile to bird, frayed scales to feather, scenario. Furthermore, those who insist that dinosaurs evolved into birds have to willfully ignore the fossil bird prints found in rock layers containing some of the earliest dinosaurs—the supposed ancestors of birds.
As you can see, the mechanisms for flight are irreducibly complex from the simplest element of the feather itself to the composite element of the organism itself being suitable for flight mechanics. However, Darwinian evolution must be accomplished through slow, gradual changes so that everything in life is explained as the slow build-up from something simple to something complex. And Darwin once wrote, “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.”[ii]
When he wrote that in his book Origin of Species, he followed that sentence with the statement that there were no such complex organs. But then again, he was writing this in 1859. What kind of biological knowledge did they have in 1859? For perspective, the American Civil War began in 1861. In all honesty, Darwin probably wasn’t aware of the amazing complexity within our bodies. He had no knowledge of DNA at all, much less how it replicated, since the DNA molecule and its structure was not discovered until 1953. Given the vast amount of information we know now, there is no intellectually honest way one could say that we do not have organs or systems that are irreducibly complex. If we observe something complex that cannot be built up by small, incremental improvements on something simple, then it could not be explained by only natural causes. It is evidence of design, and design requires a designer.
[i] W. Coleman, Georges Cuvier: Zoologist (Cambridge, MA: Harvard University Press, 1964), 172-173.
[ii] Phillip E. Johnson, Darwin on Trial (Downers Grove, IL: InterVarsity Press, 1993), 33