Feathers Could Not Evolve from Scales
The origin of feathers has stymied
evolutionists for over a century,
and a major museum is still baffled
One of the leading museums in the world admits that the origin of feathers remains a mystery[1]
by Jerry Bergman, PhD
How to Get from Scales to Feathers
The current theory is that feathers evolved from fish scales. The problem is that a transition from scales to feathers requires an enormous number of chemical, structural, and morphological changes. A new analysis of the problem by the Natural History Museum of London concluded that, in spite of over a century of work on the problem, “The origin of feathers remains a mystery.” In fact, not just the ‘how’ is a mystery, but also the ‘when’ of feather evolution.[2]
The importance of the research on the origin of feathers was described by Professor Ping Wu of the University of Southern California (Los Angeles, CA) in 2017 who wrote: “The origin of feathers is an important question in Evo-Devo studies, with the eventual evolution of vaned feathers which are aerodynamic.” [3]
Heavy Ancestors with Scales?
Theories about feather origins are based on the current idea that birds evolved from dinosaurs. This notion requires believing that dinosaur scales evolved into bird feathers. One reason for the choice of dinosaurs as a bird ancestor is that the structural similarities between dinosaurs and birds are closer than that of birds and mammals. It is the best of very poor choices for the origin of the more than 10,000 living bird species. Acceptance of dinosaur-to-bird evolution, therefore, motivates research into how scales might have evolved into feathers.
The current theory of feather evolution requires believing that from the largest known terrestrial animals—the dinosaurs—some of the smallest vertebrates today—birds—evolved by natural selection. This includes the smallest living bird, the hummingbird. In fact, the leading dinosaur ancestor candidate put forth by evolutionists is from the maniraptoran dinosaur clade, a family that includes Velociraptor and Oviraptor.[4] Consequently, the maniraptoran origins theory proposes that a 50-pound dinosaur evolved into vertebrates as small as 0.07 oz. This supposed dinosaur ancestor would have been 11,429 times greater in weight than its hummingbird descendant!
Could Scales Evolve into Feathers?
Tuatara, a “living fossil” reptile with scales (Grok/XI generated image)
The first question that evolutionists must answer is, which scale type did feathers evolve from? Many different scale designs exist. Reptile scale types includes cycloid, granular (which appear bumpy), and keeled designs (which contain a center ridge). Scales are also constructed from several distinct structures. They include the epidermis (the part on the surface) and the osteoderms, the bony structure, below the epidermal scale.
The word osteoderm literally means “bone skin.” Osteoderms function as armor plating to protect reptiles from predators and injury. They also help some animals regulate their body temperature.[5] Certain lizards use osteoderms to absorb heat from the Sun or to cool down. Crocodilian osteoderms help to regulate the acid-base balance. Some animals, including snakes, tuataras, and many lizards, lack osteoderms.
Scales also vary in size and design. The more stout, larger scales cover parts of the reptile that are exposed to physical stress, especially the feet, tail, and head. The scales around the joints are small to allow flexibility. Most snakes have extra broad scales that cover the belly from one side to the other side.
This brief review makes it clear that evolution from scales to feathers involves major changes, as is obvious from a consideration of the structure of feathers. Furthermore, much speculation exists.[6]
The Structure of Feathers
Owl feathers are custom designed for silent flight (Illustra Media)
Feathers have at least 23 functions besides flying. These include protection from wind and moisture, helping to keep warm, and controlling body temperature. Many water birds line their nests with bird feathers to help keep their eggs warm and also to provide a soft padding. Some birds use feather-covered feet in the winter to increase their foot size, similar to snowshoes to prevent them from sinking into the snow.
Some predators, including owls, have their facial feathers arranged like two dishes (facial discs) to collect and channel sounds into their ears to enable them to more accurately locate prey in the dark. Birds that hunt at night like owls can use their wings to muffle their own sounds as they approach their prey. Some fish-eating birds also swallow their own feathers to line their digestive tract to protect themselves from sharp fish bones.
The Biology of Feathers
The main building block of feathers is keratin, an indigestible protein that makes up 80 to 85% of the feather mass. The NHM article states that “The skin of reptiles is made from the same main protein (beta-keratin) as birds, but has a completely different structure.”
Ed. note: See 15 July 2014 about the differences between dinosaur “featherlike structures” and bird feathers. See also a recent Logos Research Associates presentation “Birds Are Dinosaurs: True or False”?
The amino acids required to construct feather keratin include cystine, methionine, valine, arginine, glycine, and phenylalanine. Also required are lipids, and trace minerals. Most feathers are continuously shed and resynthesized throughout the life of the bird.
Some finch feathers are vividly colored.
A typical feather consists of a central shaft, the “rachis” with branching side structures called “barbs” that extend from the central shaft forming a flat surface called the vane. The barbs then branch into smaller structures called “barbules” that interlock with tiny hooks (hamuli) on neighboring barbules forming a strong but flexible surface.
No barbs are located at the base of the feather, called the “calamus.” The base, which is hollow and anchors the feather into the skin, is called the quill from where we get the quill-tip pen. Feathers lack nerves, but can stimulate the nerves that surround the area where the feather attaches to the bird. This is a critical part of the feather design because birds adjust their feathers’ position, depending on the stimulation of these nerves. Flying would not be possible without this design. Because all of these parts are required to enable the bird to fly, the design of flight feathers is irreducibly complex.
One major difference between scales and feathers is they use very different attachment systems. Reptile scales consist of rows of hardened keratin formed from the epidermis. In reptiles the scales are formed from the dermis. Feathers are elaborate skin appendages that grow from a pouch-like cavity formed by a group of cells in the skin called a follicle. These follicles are similar to hair follicles.
Feather structure. From Wikimedia Commons.
Evolutionary Challenges
The fossil record does not show gradual advancement from primitive skin fibers to complex feathers. Rather, the first example in the fossil record, dated by evolutionists to be 150 million years old is “the complex, entirely modern feathers of Archaeopteryx.”[7] From this first bird with complex pennate flight feathers as in the figure above, evolutionists believe that all modern feathers evolved.
In their 2017 paper, Wu et al. estimated that “the evolution of feathers required integrative combination of five morpho-regulatory modules” and that “these morpho-regulatory modules were used to diversify archosaur scales and to initiate feather evolution.”[8] Each module would have required multiple coordinated mutations. If the common estimate of one percent of these mutations were beneficial[9], then from the genetic standpoint the evolution of a scale to a feather would not be feasible.
Creationists argue that, because the first functional feather would have had to be irreducibly complex in order to function as a feather, it needed all of the necessary parts from the beginning. Thus the first feather must have been essentially identical to a modern feather as shown in the diagram. Evolutionists have been unable to postulate how a fish scale could evolve into a feather containing all of the required properly assembled parts.
Conclusions
From the discussion of the functional specified complexity described above, it is clear why the “evolutionary origin of feathers has been a persistent and intractable question for more than 140 years. Two important sources have contributed to the fundamental difficulty of studying this problem: the intellectual limitations of available models, and the lack of any antecedent fossil feather structures.”[10] This is still the situation today: “The origin of feathers remains a mystery.”[11]
An example of the enormous variations in feather design. From Wikimedia Commons.
Recommended Resource: “The Genius of Flight” video from Illustra Media. See discussion of feathers starting at 4:15 through 6:10.
References
[1] Ashworth, James, The origin of feathers remains a mystery, Natural History Museum, 19 February 2025.
[2] Ashworth, 2025.
[3] Wu, Ping, et al., Multiple regulatory modules are required for scale-to-feather conversion, Molecular Biology and Evolution 35(2):417-430, DOI: 10.1093/molbev/msx295, February 2018.
[4] Andrus, Aubre (ed.). Dinosaur Atlas: When they Roamed, How they Lived, and Where We Find Their Fossils, National Geographic, Washington, DC, p. 112, 2022.
[5] Mitchel, S., Animals with Awesome Armor: Shells, Scales, and Exoskeletons, Enslow Pub, Inc., New York, NY, 2008.
[6] Alibardi, L., Dermo-epidermal interactions in reptilian scales: Speculations on the evolution of scales, feathers, and hairs. Molecular and Developmental Evolution 302b(4):365-383, https://doi.org/10.1002/jez.b.20028, 2004.
[7] Prum, Richard O., and Alan H. Brush, The evolutionary origin and diversification of feathers (PDF), The Quarterly Review of Biology 77(3):261–295. doi:10.1086/341993, PMID 12365352, S2CID 6344830, September 2002.
[8] Wu, Ping, et al. Note that five modules exceeds the number of integrated parts as Michael Behe’s mousetrap model for irreducible complexity— Ed.
[9] Schultz, Stewart and Michael Lynch. 2017.
[10] Prum and Brush, 2002. Mutation and Extinction. Evolution. 51(5):1363-1371. https://onlinelibrary.wiley.com/doi/abs/10.1111/j.1558-5646.1997.tb01459.x
[11] Ashworth, 2025.
Dr. Jerry Bergman has taught biology, genetics, chemistry, biochemistry, anthropology, geology, and microbiology for over 40 years at several colleges and universities including Bowling Green State University, Medical College of Ohio where he was a research associate in experimental pathology, and The University of Toledo. He is a graduate of the Medical College of Ohio, Wayne State University in Detroit, the University of Toledo, and Bowling Green State University. He has over 1,900 publications in 14 languages and 40 books and monographs. His books and textbooks that include chapters that he authored are in over 1,800 college libraries in 27 countries. So far over 80,000 copies of the 60 books and monographs that he has authored or co-authored are in print. For more articles by Dr Bergman, see his Author Profile.