Chapter VI - Difficulties of the Theory
In this chapter, Darwin provided hypotheses to counter some of the most obvious objections to his theory of the mechanistic evolution of all species from a common, 1-celled ancestor. The first problem he faced was the absence of the innumerable transitional forms in the fossil record between "progenitor" and offspring species. The "crowd of difficulties" included the question of how natural selection acting on variation produced complex interdependent structures like the eye and at the same time accounted for the smallish tail the giraffe uses to swat at flies? Why does inter-species crossing produce no offspring or sterile offspring and crossings of varieties within a species produce hybrid vigor? How does a bat evolve from a wingless four-footed ancestor? And, foremost in Darwin's model was his mantra: "natura non facit saltum." Speciation cannot be abrupt. That is, speciation, in order be a wholly natural process, must not occur rapidly but ever so gradually by innumerable, infinitesimally small steps. That is Darwinian gradualism and everything else is not.
Critique
Good questions. The mantra "natura non facit saltum" is the foundation of Darwinian evolution and everything else is not; that is, is not Darwinian. We shall see that no weaseling can successfully skirt the evidence. Of interest, neo-Darwinists have largely ignored Darwin's concern with abrupt speciation because now we know that is how speciation happens. Neo-Darwinism is fundamentally non-Darwin.
On the Absence or Rarity of Transitional Varieties
The main reason transitional forms (missing links) failed to appear in the fossil record is because that record was incomplete (Page 162-162). Another reason for the absence of transitional forms was that they were relatively short-lived. A single species that inhabited a vast area would have access to various habitat types; for example, plains, rolling hills, and mountainous terrain. Varieties of this species would evolve through natural selection acting on variation to specialize in the mountains and on the plains. Darwin called the area between the evolving plains variety and evolving the mountain variety the "intermediate zone."
In Darwin's mind, the intermediate varieties developed in the "intermediate zone"/"neutral territory" and then spread out to replace the parental types across the different habitat types. Thus, the population of each of the innumerable steps, developed in the relatively narrow "intermediate zone" comprised relatively few individuals compared to the parent populations they replaced. Because they were relatively few in number, the innumerable intermediate forms were more subject to extermination by disease, adverse weather, and predation and were therefore less likely to appear in the fossil record.
Darwin insisted that the evolution of whole populations over a large continuous area provided the best fit with his gradualist model though physical isolation also played a part in speciation:
...many perfectly defined species have been formed on strictly continuous areas; though I do not doubt that the formerly broken condition of areas now continuous, has played an important part in the formation of new species... (Page 163).
Critique
Darwin insisted that the gradual evolution of species took place in large continuous populations. But, in an effort to explain the lack of intermediates in the fossil record, he suggested that the innumerable transitional forms were short-lived and few in number; that is, there were innumerable transitional forms but each form had few representatives to be fossilized for the record.
Unfortunately, the role played by the intermediate species/variety in the "neutral territory" was not clear. In Darwin's illustration, the missing link coexisted in time and was spatially adjacent to and connected with the species/varieties it replaced. The superior characters of the transitional form enabled it to replace the individuals of the same species across the landscape and then the transitional form died off precipitously because the numbers of individuals with the superior characters in the neutral territory were few in numbers. These superior individuals were more subject to extinction and died from stochastic events because there were fewer of them?
Thus the transitional forms existed in some form of isolation without physical isolation and their superior characters enabled them to replace adjacent varieties of the same species across the landscape. The superior characters of transitional forms expanded across the landscape while the superior individuals themselves remained in the neutral territory where stochastic events eliminated them. One unfortunate factor tied to being short-lived was that the transitional forms had little time to evolve gradually?
Was Darwin talking about the splitting of species through some form of isolation in the context of the gradual evolution of an entire population? This section represented considerable weaseling to make some kind of attempted mix from conflicting observations; e.g., lack of intermediates in the fossil record, rapid extinction of parental stock by superior progeny that evolved gradually, and isolating mechanisms without physical isolation. A certain amount of the Origin is difficult to read and understand simply because it is pure contradictory, mumbo-jumbo nonsense.
Odd it is that with physical isolation, speciation events still failed to provide the evidence of the innumerable intermediate forms. So, in Darwin's mind, there had to be a narrow "neutral" or "intermediate zone" within a wide-ranging, continuous population for the production of superior intermediates that were inferior in numbers. And, of course, two or more incipient species had to evolve simultaneously from the same base population in order to provide support for branching in the evolutionary tree of life.
On the Origin and Transitions of Organic Beings with Peculiar Habits and Structure
In this discussion, Darwin provided a number of examples of species he considered to represent transitions between different species' habits of life. He cited flying squirrels and flying lemurs as illustrations of how bats evolved wings for flight. The former species used the skin flap joining their bodies and legs to glide between trees. This ability enabled them to escape their enemies and access food resources more quickly than similar, competing species. The structure of these species show how a bat developed flight from a gliding ancestor. Likewise, the flying fish that leaps out of the water and glides in the air to escape its enemies is a species transitioning toward actual flight.
The mink is a good swimmer. It catches fish like an otter in the water and on land forages like a weasel. The mink therefore represented a transition between the habits of an aquatic otter and a terrestrial weasel.
Some species show transition primarily in their habits and not their structure. The change in habit/behavior can change the structure of the species and sometimes a developing change in structure will change the habit of the species. A colleague of Darwin's observed an example of a change of habit:
In North America the black bear was seen by Hearne swimming for hours with widely open mouth, thus catching, almost like a whale, insects in the water (Page 170).
Another example of species change of habit without change of structure is the way the water ouzel (Cinclus mexicanus) gathers food. This bird is highly aquatic in its search for food but its structure is that of a thrush:
...the acutest observer by examining its dead body would never have suspected its sub-aquatic habits ... (Page 170).
Darwin also noted examples of birds using their rudimentary wings for functions other than flying:
Yet the structure of each of these birds is good for it, under the conditions of life to which it is exposed, for each has to live by a struggle. (Page 170).
Thus, rudimentary structures diminished by a lack of use can assure the survival of a species but not as well as that of the extinct ancestor's perfected structure, in this case, the flying wing.
Darwin's observations of what he considered poorly adapted species led him to conclude that God did not create these species:
He who believes that each being has been created as we now see it, must occasionally have felt surprise when he has met with an animal having habits and structure not in agreement (Pa
ge 170).
Darwin also noted that the transitional forms are less likely to appear in the fossil record because their lack of perfection of parts did not enable them to survive as well as the perfected forms; e.g., gliders as opposed to the descendent flyers (Page 170).
Critique
Pre-bats and pre-pterosaurs (flying reptiles) have not appeared in the fossil record. Facts have more merit than structured theories.
According to Darwinian evolutionary theory, the transitional forms were superior to their predecessor species in their ability to survive and therefore replaced them. Thus, the transitional forms should appear as frequently in the fossil record as their ancestors. But Darwin insisted that the transitional forms were hard to find in the fossil record because they were inferior to their successor, improved species. Therefore the fossil record is replete with the successors but not the transitional forms that preceded them. Darwin obviously struggled with uncooperative fossil evidence. The lack of transitional forms in the fossil record fails to support Darwinian gradualism. That is fact.
Organs of Extreme Perfection and Complication
To suppose that the eye with all its inimitable contrivances...could have been formed by natural selection, seems, I freely confess, absurd in the highest degree (Page 170).
Thus, Darwin acknowledged the apparent inability of natural selection to produce highly specialized, complex organs but also noted the materialist mandate: "Vox populi, vox Dei". That is, science, does not trust the voice of the people nor the voice of God.
We are not sure what Darwin meant by "science" but he did provide his views on how natural selection could make an eye in spite of his own expressed doubts about his views. After all, why stumble over the origin of the eye when one willingly accepts the unknown origin of life to be a wholly natural process:
How a nerve comes to be sensitive to light hardly concerns us more than how life itself originated... (Page 172).
If the phenomenon is complicated beyond generalized explanation, philosophical materialism assumes that mind had nothing to do with it; including the materialist author's mindful use of logic and subsequent conclusions.
Darwin noted that it is not possible to trace the development of the eye through a study of ancestors. Therefore he pointed out how existing animals in different classes have different forms of eyes, some primitive; some advanced. Some members of the class Articulata (previous classification system included insects, segmented worms, and spiders) for example, possess:
...an optic nerve simply coated with pigment, the latter sometimes forming a sort of pupil but destitute of lens or other optical contrivance (Page 173).
Insects have more advanced eyes:
With insects it is now known that the numerous facets on the cornea of their great compound eyes form true lenses and the cones include curiously modified nervous filaments (Page 173).
Darwin also referred to the "eye" of the lancelet (classed as a primitive vertebrate), which has "a little sack of transparent skin, furnished with a nerve and lines with pigment..." (Page 174). The primitive "eyes" of some species enable them to distinguish light from darkness.
Darwin asked us to consider "the diversified, and graduated range of structure in the eyes of lower animals" (Page 173). Given innumerable ancestors and great expanses of time, natural selection acting on variation could produce the eye of a human or eagle (Page 173). Because of the complexity of the eye, its appearance depended upon a very gradual process.
Others objected:
...that in order to modify the eye and still preserve it as a perfect instrument, many changes would have to be effected simultaneously, which, it is assumed, could not be done through natural selection... (Page 173).
Darwin answered that his study on the variation and evolution of domestic animals showed that not all modifications happened simultaneously but were "extremely slight and gradual" (Page 173).
Critique
Today, evolutionary biologists still struggle to explain the gradual evolution of the eye. Lamb (2011) stated that the Cambrian explosion some 490 million to 540 million years ago provided the groundwork for the evolution of the complex eye. He described the Cambrian explosion as: "This burst of evolution..." He further noted that:
the eye evolved from a light-sensing but nonvisual organ into an image-forming one by around 500 million years ago.
In reference to the appearance of the lens, the researcher said:
We do not know exactly when this modification happened, but in 1994 researchers at Lund University in Sweden showed that the optical components of the eye could have easily evolved within a million years. If so, the image-forming eye may have arisen from the nonvisual proto-eye in a geologic instant.
We see (no pun intended) wonderful and natural selection gradually working ever so slowly, scrutinizing every opportunity to evolve complex organs ...rather at lightning speed with the accompanying descriptors "explosion," "burst of evolution," and "geological instant". Once again, Darwinian gradualism in a hurry...a lens in one million years? That is about a third of the life of single mammalian species. The fossil record remains mute on the ever so gradual, albeit abrupt development of irreducibly complex organs.
Seldom do fossil remains provide information on soft body parts like eyes. Also, transitional forms of organisms are essentially absent from the fossil record. Thus, no information is available that shows how a nerve evolves sensitivity to light. We therefore have only guesses about the origin of the eye, the cell, the blood clotting system or other complex biological systems; for example, the origin of coded information housed in the DNA molecule.
Michael J. Behe (1998) described examples of "irreducibly complex" molecular machines and biological systems that could not have evolved step-wise as posited by Darwin. The bacterial flagellum, for example, which is used as a propulsion motor for some 1-celled organisms, has forty different working parts. Each part must be fully functional for the molecular motor to work. There is no survival value in having a less than fully functioning and therefore fully developed flagellum with its integrated working parts. According to every day observations, intelligent agents are always responsible for the production of complicated machinery. Perhaps we should forgive Darwin's naivete; he did not have an inkling of the inexplicable working complexity of cells and biological information systems.
Modes of Transition
Darwin speculated on organs changing functions through numerous "transitional grades". He stated that if organs developed by any means other than by
...numerous, successive, slight modifications, my theory would absolutely break down" (Page 175).
He said that the swim bladder in fishes, for example, originally developed for the purpose of flotation and later for respiration:
(The) swim bladder is homologous, or "ideally similar" in position and structure with the lungs of the higher vertebrate animals; hence there is no reason to doubt that the swim bladder has actually been converted into lungs, or an organ used exclusively for respiration" (Page 176).
Darwin provided what he considered evidence of organs changing into other organs in different classes of animals. He noted that the folds in the sides of the neck area that appear during the embryonic development of higher vertebrate animals and "the loop-like course of the arteries" show the former location of fish gills (Page 176). He noted that the embryos of fish, reptiles, amphibians, birds, and mammals go through developmental stages that resemble each other. Thus, Darwin and others assumed that the embryonic development of vertebrates appeared similar because those observers assumed similar structures derived from corresponding embryonic parts. This belief lead Darwin to conceive a close relationship between embryonic development and evolutionary history. Based on observations of embryonic development of different vertebrate classes, Ernst Haeckel coined his "Biogenetic Law": "Ontogeny recapitulates phylogeny." That is, the development of the human embryo, for example, includes fish and reptile stages, showing genetic linkage.
/> This section ended with a discussion of species reproducing at a younger age and thereby losing the characters of old age. A professor Cope and "others" in the United States had insisted on this "mode of transition". Darwin noted that he did not know how rapidly a species might change in order to reproduce at a younger age but he believed that the characters of old age and youth developed through slight modifications over long periods of time. Darwin provided no observations from professor Cope to substantiate animals reproducing at a younger age.
Critique
Darwin hypothesized that the swim bladder of fishes developed into the lungs of higher vertebrates; i.e., amphibians, reptiles, birds, and mammals. However, the 12 January 1010 issue of Time Magazine (Verbatim section, 22) reported that paleontologists had recently found a set of fossilized footprints in Poland that show four-legged animals on land some 400 million years ago. If true, air-breathing animals were on land before or coexisting with the first appearance of bony fishes in the sea. Given this recent evidence, again, if true, the ancestral fish air bladder evolved simultaneously with or after the appearance of an air-breathing quadruped. Perhaps the quadruped entered the water and lungs evolved into the fish air bladder? Otherwise it seems rather ingenuous of terrestrial quadrupeds to have evolved simultaneously with or even before their fish ancestors?
Oddly enough, National Geographic nor Smithsonian nor Scientific American nor Nature rushed to report the "new" quadruped. Instead, they ignored it. Likely, they recognized its appearance as an anomaly not representative of evolutionary laws?
Speaking of "laws," Ernst Haeckel's "Biogenetic Law" was discredited. To quote Denton (1986, 146):
There is no question that, because of the great dissimilarity of the early stages of embryogenesis in different vertebrate classes, organs and structures considered homologous in adult vertebrates cannot be traced back to homologous cells or regions in the earliest stages of embryogenesis. In other words, "homologous" structures are arrived at by different routes.
Special Difficulties of the Theory of Natural Selection
This section provided several examples of organs and processes that Darwin's theory of gradual development does not appear to explain. Examples included questions as to the origin of electric organs in some fishes, luminous organs in species from different families of insects, eyes in the octopus and squid as opposed to those of vertebrate animals, the development of "hair-claspers" in species of parasitic mites representing different families, and the various complex mechanisms of flower fertilization. Because like organs and complicated processes appear in species from different families and, in some cases, different orders, Darwin believed that these organs and processes were not the result of inheritance from a common "progenitor". For example, the eye of the octopus and the eye of a vertebrate animal both require "transparent tissue, and must include some sort of lens for throwing an image at the back of a darkened chamber" (Page 180). Because the eye of the octopus and the vertebrate animal did not come from a common ancestor, nature got lucky:
As two men have sometimes independently hit on the same invention, so in the several foregoing cases it appears that natural selection working for the good of each being, and taking advantage of all favorable variations, has produced similar organs, as far as function is concerned, in distinct organic beings... (Page 180).
Darwin insisted that complex functions and like organs in disjunct species appear through natural selection acting upon slight gradations over long periods of time. He saw no way for the complexities of living organisms to develop rapidly:
...as indeed is shown by that old, but somewhat exaggerated, canon in natural history of "Natura non facit saltum"... Why should not Nature take a sudden leap from structure to structure? On the theory of natural selection, we can clearly understand why she should not; for natural selection acts only by taking advantage of slight successive variations; she can never take a great and sudden leap, but must advance by short and sure, though slow steps (Page 184) (emphasis, mine).
Critique
Contrary to Darwin, the fossil record is now complete enough to show that species appear and disappear abruptly and that adaptive radiation/speciation is, relative to the Darwinian model, explosive (Denton 1986, Stanley 1979, Johnson 1991, Wells 2000).
Insofar as the development of the eye in mice, octopuses, and fruit flies is concerned, all derive from the same or similar gene. The gene is:
...so similar that you can put the mouse gene into a fruit fly that's missing that gene and you can get the fruit fly to develop its eyes as it normally would (Strobel 2004:54).
Furthermore, neurobiologists recently discovered that though mice and men have 90% of the same/similar genes, expression patterns for those genes in the brains of men and mice differ a third of the time, producing different brain functions (Lein and Hawrylycz 2014). And, in comparing gene function in the brains of monkeys and humans, these researchers discovered that:
The fundamental similarity of genetic activity in human and monkey brains points to the wiring among the neurons, rather than the genetic activity within the cells, as the likely source of our distinctiveness.
Genes within informational context, not gene mutation accounts for species distinctions. Meyer (2009: 471-476) discussed the distal-less gene that regulates the development of insect legs, sea urchin spines, and mouse legs. Odd it is that all that evolution and gene mutation over hundreds of millions of years failed to produce significant changes in genes that regulate the development of eyes and limbs of such disjunct classes of organisms. Rather, as Meyer noted, it is the "large informational context in which the gene finds itself" that determines gene expression:
Indeed, the function of many genes and proteins is determined "top-down," by the larger system-wide informational and organism context - by the needs of the organism as a whole.
In other words, epigenetic (above/beyond gene) information of unknown origin, can be more important to gene expression than gene mutation, the hallmark mechanism of neo-Darwinism.
Darwin had no idea just how lucky nature had to be to independently produce from scratch the same/similar eye gene in the octopus and the vertebrate animal. Douglas Axe calculated that the chances for producing a simple, functional protein of modest length (a specified sequence of 150 amino acids) to be 1 chance in 1074 (Meyer 2013:185-204). With there being some 1065 atoms in the Milky Way Galaxy, imagine the likelihood of nature hitting upon the idea of making the same/similar gene for the eye twice. Also, throw in all those other functional proteins and genes needed for all the different nerve and muscle connections required by the eyes to function in the different species. There are a lot of big numbers out there, but doubtless, probabilities for the multiple eye project used a bunch of them.
The facts do not fit Darwin's speculations. Given our current level of knowledge, holding on to Darwinian gradualism requires a lot of fortitude, hope, and blind loyalty to a materialist philosophy.
Organs of Little Apparent Importance, as Affected by Natural Selection
Darwin discussed the parts of species that appear to provide no particular survival values; e.g., the tail of the giraffe, the down on fruit, and the color of hair of quadrupeds. He provided speculations that might explain the presence of apparently unimportant parts. He suggested that perhaps the part just appeared unimportant but was in fact important to the survival of the species. Secondly, the part may just have been inherited from an ancestor that had a more important use for the character. Thirdly, if one considers the great amount of variation among domestic breeds, one may conclude that the "organs of little apparent importance" should not create much concern.
Critique
Darwin's assumptions that "organs of little apparent importance" were of little importance were nothing but assumptions that provided no information and therefore no support for his theory of gradual evolution. He did say that what appeared to be useless organs or parts may in fact provide useful functions. Darwin ignored that possibil
ity when he argued that "rudimentary" or assumed to be useless body parts among species merely pointed to common ancestry. Otherwise, a character of some importance could represent analogous developments; for example, dorsal fins in dolphins and sharks.
Utilitarian Doctrine, How Far True: Beauty, How Acquired
Some protestors of Darwin's theory told him that the beauty and complexity ("perfection") common in nature pointed toward creation by a supreme being. Darwin made efforts to counter such arguments. He said that if there was beauty in nature before the appearance of man, that beauty was not created for man's delight. He asked if we are to believe that the shells of long extinct forms were created so modern man could appreciate their symmetry under his microscope. He was also of the opinion that flowers and fruit were colorful to attract insects that fertilize flowers and animals that eat the fruit and spread the seed (Page 189). The reason some birds, fishes and butterflies are gorgeous is because the females of the species selected for beauty. Darwin did admit:
...the reception of a peculiar kind of pleasure from certain colours, forms, and sounds... first developed in the mind of man and of the lower animals, is a very obscure subject" (Page 190).
Darwin further addressed "perfection" in nature:
Natural selection cannot possibly produce any modification in a species exclusively for the good of another species...If it could be proved that any part of the structure of any one species had been formed for the exclusive good of another species, it would annihilate my theory, for such could not have been produced through natural selection (Page 190).
In view of nature's "perfection," he suggested that there were flaws in the human eye, that plants and animals from Europe were eliminating native species considered to be perfectly adapted to habitats in New Zealand, and that the death of a stinging bee represented imperfection in nature. Another example of inefficiency and imperfection in nature is the production of "dense clouds of pollen by our fir-trees, so that a few granules may be wafted by chance on the ovules" (Page 194).
Critique
Judeo-Christianity contends that nature was beautiful before the appearance of man because Genesis 1 states that God, who had an eye for beauty, created the heavens and the earth to be "good," not perfect, before he made mankind. God's concept of "good" is translated to mean harmonious, beautiful, and complex. The Bible also states that man's disobedience led to a fallen state of imperfection in the natural world. Creative mind is also behind Darwin's unanswered quest concerning the origin of the aesthetic in man and other animals.
As per Darwin:
Natural selection cannot possibly produce any modifications in the species exclusively for the good of another species...
Perhaps natural selection did not determine that a lone, dying widow woman will all her belongings to her beloved cat? Nor did natural selection determine that we make laws to protect and preserve rare and endangered species and their habitats? What "modifications" from what source produced a non-utilitarian appreciation in mankind for beauty in other species? Certainly the love of mankind for other species defies the self-preservation mandate of natural selection and would prove deadly to Darwin's theory because inter-species love that leads to a sacrifice of resources for the preservation of other species could not have been produced through natural selection. Thus, Darwin's words oft quoted after his death contradicted/"annihilated" an early affirmation of faith in the mechanics of his evolutionary theory:
The love for all living creatures is the most noble attribute of man.