Chapter I - Variation under Domestication
Darwin believed that man's process of selection for varieties of domestic plants and animals was basically the same biological process that nature uses in the wild to create species. That is, he did not recognize a difference between micro- and macroevolution. Microevolution produces varieties within the genetic potential of a species through selective breeding by man or by natural selection. By contrast, macroevolution is the theory that all life forms evolved from the same 1-celled organism through natural selection acting on random variation.
In the case of domestic varieties, according to Darwin, man selected which plants or animals with specific characteristics will reproduce, and in nature, the process of natural selection chooses which individuals will survive to reproduce. Darwin believed that domestic varieties of the same species were in the process of becoming new species.
Critique
Today, we see the comparison of Darwin's phyletic evolution (gradual changing of a whole population of organisms into a new species) with the development of domestic varieties a bit ludicrous... in light of the fact that breeders of dogs and pigeons and wheat have, notwithstanding random mutations, failed to produce anything but varieties of those species. Genetic engineering/modification, however, by intelligent design may enable us to produce some mixed creatures from parental materials? Maybe mankind will realize Darwin's dream that man can make new species, with monsters in the mix?
Causes of Variability
Darwin believed that the "nature of the organism" and its environment produced variation in the individual (Pages 31-32). He provided several examples to explain how "the nature of conditions" caused variation in a species. He said that the amount of food can affect the size of the individual and the nature of the food can affect the species' color. Climate influences the toughness of the skin and the density of the hair (Page 32). His belief was that such changes were newly acquired and were incorporated into the nature of the organism and that those new characters were heritable by the individual's offspring.
Darwin explained:
Many facts clearly show how eminently susceptible the reproductive system is to very slight changes in the surrounding conditions.
By contrast, surrounding conditions do not affect the reproductive systems of rabbits and ferrets because "they breed freely" in hutches (Page 33).
The "nature of the organism" had obvious influence on "variation" because Darwin observed that frequently species produced similar looking offspring under different environmental conditions. It appears that what Darwin meant by "variation" was the production of individuals that looked different from the parental stock. The "nature of the organism" was an obscure concept, something that resisted change in the individual and at the same time, something that enabled the individual to change its physiology and structure in response to environmental changes or in response to changes in its own behavior.
Critique
Darwin's view that the amount and quality of food alter inheritable characters and create additional variation in the species found some validation in recent epigenetic studies. John Cloud (2010:51) reported:
...if you over stimulate genes for say, obesity or a shortened life span, your kids can inherit these over activated sequences. That could mean a lifetime of battling unfavorable gene expression.
However, contrary to Darwin, the production of calluses on the skin from use and seasonal thickening of the fur of animals in winter are physiological reactions that do not represent newly acquired variation in the individual. It is surprising that Darwin failed to notice or mention that numerous mammals in temperate and colder climates have different coats of hair in summer and in winter. The variation that appears in domestic varieties generally reflects variation in the extant gene pool or gene mutation, which would most often reduce survivability in the wild.
Darwin noted that the "nature of the organism" obviously influenced available variation because he noticed that species frequently produce like offspring in different environments. That is, the "nature of the organism" controls available variation by not changing its form regardless of the different habitats it occupies. And, on the other hand, the "nature of the organism" is thoroughly plastic and readily changes its structure and organs in response to changes in its environment or in response to changes in its own behavior.
Unbelievably, in the first case, Darwin observed that numerous species were apparently the same in different environments, which discredited his assumptions about the organism changing itself in a Lamarckian manner to fit its surroundings. In the second case, from his imagination, Darwin reaffirmed his belief that the "nature of the organism" created variation by automatically adjusting its own structure and organs to better fit its environment. Darwin's purpose here was to ignore his observations and, from his basic Lamarckian assumptions, insist that organisms were flexible and were constantly evolving into new organisms.
If changes in the living conditions produce variation in the organism, variation represents a vitalistic, programmed, and/or epigenetic response to the environment. Such concepts point to highly complex, programmed adaptations. See "Epigenetic Niche-match" in "Notes/Definitions" at the end of this essay.
I find it hard to understand why Darwin failed to question the complexity of physiological processes required to produce variation in a species. He appears to have looked at generalized results, all of which he classed as "principles," "rules," or "laws of nature" to gloss over the complexity of the unknowns inherent in his observations. "Law" was the gap-word for the inexplicable; an iteration insistent upon belief in metaphysical materialism.
Effects of Habit and of the Use or Disuse of Parts; Correlated Variation; Inheritance
Darwin believed that "changed habits produce an inherited effect..." and the "increased use or disuse of parts" can change the inheritable characters of an animal or plant (page 34). It was a simple law of nature that if an animal stretched its neck to reach higher forage, for example, the giraffe, the individual animal would get a slightly longer neck and would pass that character on to its offspring. Acquiring a slightly longer neck produced a new "variation". And, if the giraffe stretched its neck less often because forage was closer to the ground, the individual giraffe would develop a shorter neck. Thus, Darwin was a firm believer in the mysteries of Lamarckian evolution.
As was his practice, Darwin cited examples of the laws of variation from his observations of domestic animals. He observed that the wing bones of the domestic duck weigh less proportionate to the rest of the bird's bones and the leg bones of the domestic variety weigh relatively more than they do in the wild duck. Darwin said that the reasons for these changes and differences between the wild duck and the domestic duck were because the domestic duck flies less and walks more than does the wild duck. He also noted that utters of domestic goats and cows were larger from use in countries where people milked those domestic animals for food/drink.
By "correlated variation," Darwin simply meant that when a variation appears (a plant or animal that looks different from its parents), the resultant animal/plant is often different from its parents in several structures. He stated:
...if man goes on selecting, and thus augmenting, any peculiarity, he will almost certainly modify unintentionally other parts of the structure, owing to the mysterious laws of correlation ...the number and diversity of inheritable deviations of structure, both those of slight and those of considerable physiological importance, are endless (Page 35).
Thus, Darwin believed in the total plasticity of biological life; that individual animals and plants change and that over time they, through numerous generations, can change into limitless different kinds of beings. He believed that the individual changes in its inheritable characteristics simply by the use or disuse of its parts.
Darwin further noted that "The laws governing inheritance are for the most part unknown" (Page 36). It appears he meant laws other than those based on his observations as des
cribed above. I assume this is the case because Darwin produced emphatic/dogmatic statements about the total plasticity of species and how the individual acquires inheritable changes in its physiology and structure through changes in its behavior.
Critique
Again, Darwin's belief that the giraffe's neck grew longer because the animal stretched its neck to reach higher browse, was a Lamarckian and vitalistic concept. Why would an organism be organized/programmed to a point where it acquires a specifically needed character by simply repeatedly expressing that need? Imagine the first pre-mammalian mother deciding that she could better nourish her offspring by the development of a mammary system; and the system begins in infinitely small steps to accommodate her vision for the future. All she has to do to get the system started is to behave like she is providing some form of pre-milk for her offspring. The organism would have to be programmed to accommodate new biological information that can produce complex changes in the structure and functions of organs.
Another example: how could natural selection, operating through environmental pressures ever select for a reduction in the 6-ounce femur in a whale? And if the reduction of the whale's femur occurred because of disuse, what is the origin of the program for instigating small changes of no apparent survival value? Of course, neo-Darwinists believe random mutation is the answer to all evolutionary changes.
However, the chances of random mutation producing anything new are remote. Random mutation simply shuts down or deregulates gene expression; it cannot produce new regulatory systems, genetic circuitry, nor molecular machinery through the development of new protein-protein interactions. Behe (2014:154) observed:
Since we see no new protein-protein interactions would develop in 1020 cells, we can be reasonably confident that, at least, no new cellular systems needing two new protein-protein interactions would develop in 1040 cells - in the entire history of life...
As noted above, Behe (2014:155,154,135,172) said that "In 1020 copies, HIV developed nothing significantly new or complex" such as protein-protein interactions, and that the probability of developing a functional fit between two proteins through random mutation is also about one in 1020. Thus, any new cellular system that required two new protein-protein interactions, could expect to achieve those add-ons through random mutation with one chance in 1040 cells. According to Behe, that's more cells than likely have ever existed in the history of the world. Such odds play poorly for Darwinian evolution through random mutation when one considers, for example, that the common and abundant cilium, a hair-like paddle used to move some 1-celled organisms around, is composed of hundreds of integrated protein parts.
Character of Domestic Varieties; Difficulty of Distinguishing between Varieties and Species; Origin of Domestic Varieties from One or more Species
Darwin believed there were so many different breeds of domestic animals because these animals descended from several distinct wild species. He believed that the appearance of varieties of domestic animals was a step toward creating a new species. He referred to varieties of domestic species as "incipient species." He noted:
...domestic races of the same species differ from each other in the same manner as do the closely-allied species of the same genus in a state of nature, but the differences in most cases are less in degree (Page 38).
Critique
Darwin believed that there was so much variation among domestic species because those domestic species were derived from the crossbreeding of different wild species. Darwin was generally wrong about domestic species originating from the cross-breeding of different wild species and he was incorrect about domestication creating new species. Domestic plants and animals, regardless of numerous varieties and random mutations, remain within their respective species boundaries.
Breeds of the Domestic Pigeon, their Differences and Origin
In this section, Darwin described his views on the breeding of domestic pigeons. He concluded that through selective breeding, mankind had produced breeds that would pass for distinct species if encountered in the wild:
Altogether at least a score of pigeons might be chosen, which, if shown to an ornithologist, and he were told that they were wild birds, would certainly be ranked by him as well defined species (Pages 42-43).
Darwin also used his observations on the breeding of pigeons to conclude that slight changes accumulated through successive generations could produce new species. His observations of domestic pigeons enabled him to conclude that species produce new species.
Critique
Darwin thought domestication could produce new species. Today we view the production of domestic varieties of plants and animals to as a result of random mutation and microevolution within species boundaries.
Principles of Selection Anciently Followed, and their Effects
Darwin was redundant in this discussion of how man has developed varieties of domestic animals through selection. He noted that variation is acquired by the individual plant or animal by changes in the species' behavior or by environmental conditions that cause the individual to change in a Lamarckian fashion. The variation acquired by the parent then passes to the offspring and man then selects the characters he wants to breed for by breeding among offspring with the desired characters. What Darwin was fishing for in this section was an emphasis on the process of selection for slight changes. In the case of domestic varieties of plants:
...the continued selection of slight variations, either in the leaves, the flowers, or the fruit will produce races different from each other chiefly in these characters (Page 50).
Critique
Selection by man for desired characteristics in domestic varieties and the development of select varieties has been rapid, relative to Darwin's concept of time required for the gradual evolution of species populations. Thus, because the development of domestic varieties has been relatively fast and because domestication failed to produce new species, Darwin's use of the microevolutionary process of domestication of plants and animals was not applicable to his concept of the gradual evolution of all species from a single progenitor. If domestication affirms any "law of nature," it supports the stasis of the species class. Darwin continued to emphasize the gradual evolution of species because the rapid production of complexity in organisms smacked of programming by an intelligent agent.
Today scientists use particle guns to inject DNA fragments into plant cells to improve the genetic health of and fruit production by tomatoes. The tomatoes remain in the same species and the genetic change fostered by intelligent agents is heritable by the offspring (Freedman 2013). There is nothing Darwinian about any process performed by intelligent agents.
Methodical and Unconscious Selection
In this section, Darwin expressed his view that man selected for domestic varieties of plants and animals and that the selection process that made huge differences in domestic species was slow and worked on insensible changes. He shared an anecdote on the development of the English pointer to make his point that the selection process was slow and "insensible":
It is known that the English pointer has been greatly changed within the last century, and in this case the change has, it is believed, been chiefly effected by crosses with the foxhound; but what concerns us is, that the change has been effected unconsciously and gradually, and yet so effectually, that, though the old Spanish pointer certainly came from Spain, Mr. Borrow has not seen, as I am informed by him, any native dog in Spain like our pointer (Page 51).
In this instance, Darwin was working on his case to prove that selection in the state of nature could likewise produce all existing species from the same primitive ancestor (1-celled organism). His thoughts ran along these lines because he believed species were capable of unlimited change. Species were totally plastic and had the potential to become every other species, given time and the power of natural selection.
Critique
Notwithstanding his observations of domestic breeds of plants and animals and access to anecdot
es about domestication processes, Darwin failed to notice that breeders of dogs, pigeons, horses, and wheat always produced dogs, pigeons, horses, and wheat. He stated that breeders generally were not aware of what they were selecting for in the production of domestic animals and that the process of domestication was slow, much like the gradual evolution of a species population through natural selection. To the contrary, I do not believe breeders have been blind to what they were looking for in the process of domestication and I believe they often obtained results rapidly. Nor do I believe that domestic species resulted from the blending of several different species in the wild. As stated above, Darwin's comparisons of domestication with his concept of macroevolution were invalid.
Circumstances Favorable to Man's Power of Selection
This section is a jumbled and redundant. Darwin declared:
A high degree of variability is obviously favorable, as freely giving the materials for selection to work on... (Page 55).
The only limits on the production of variability would occur if the species did not change its behavior and thereby increase or decrease the use of its parts or if environmental conditions do not change the species. In this case, man would have less variation available to select for in the domestication of plants and animals.
Darwin also noted:
When the individuals are scanty all will be allowed to breed, whatever their quality may be, and this will effectually prevent selection (Page 55).
Under the process of developing domestic species, Darwin dismantled his earlier statements on the total plasticity of species to produce unlimited variation:
No doubt, as Mr. Wallace has remarked with much truth, a limit will be at last reached. For instance, there must be a limit to the fleetness of any terrestrial animal... (Page 57).
This seems reasonable. It is not likely dog breeders will develop a greyhound that runs 600 miles per hour (966 kilometers per hour).
Darwin's concluding statement for this section and Chapter I:
Over all these causes of Change, the accumulative action of Selection, whether applied methodically and quickly, or unconsciously and slowly but more efficiently seems to have been the predominant Power (Page 58).
Critique
Darwin's concluding remark at the end of Chapter 1 was overstated and preachy. He failed to distinguish between variation expressed within species boundaries and his theory of the gradual evolution of a population of organisms into a new species. His supposition that microevolutionary processes apply to the macroevolution of all life forms from a common primitive ancestor (1-celled organism) was incorrect. I quote Denton (1986:86):
For Darwin, all evolution was merely an extension of microevolutionary processes. Yet, despite the success of his special theory, despite the reality of microevolution, not all biologists have shared Darwin's confidence and accepted that the major divisions in nature could have been crossed by the same simple sorts of processes. Skepticism as to the validity of the extrapolation has been generally more marked on the European continent than in the English speaking world. German zoologist, Bernhard Rensch, was able to provide a long list of leading authorities who have been inclined to the view that macroevolution cannot be explained in terms of microevolutionary processes, or any other currently known mechanisms.
Darwin noted that "Selection" was the "predominant Power" that produced "Change" (Page 58). Notwithstanding the needless capitalized letters for emphasis, Darwin only observed that man's selection produced domestic varieties of plants and animals. Perhaps he capitalized "Power" and "Selection" and "Change" to emphasize concepts he would subsequently apply to his macroevolutionary theory. But what has remained obvious about the domestication process is that breeders derived dogs from dogs and pigeons from pigeons without changing the species into a new species. I repeat myself in order to respond to Darwin's redundancy.
One can only guess at what Darwin meant by:
When the animals are scanty, all will be allowed to breed, whatever their quality may be, and this will effectually prevent selection (Page 55).
Because this statement was made in the middle of a discussion on parallels between domestication of species and macroevolution in the wild, I suspect Darwin was saying that inbreeding in a small population in isolation provides little variation for natural selection to act upon. This interpretation would explain his doubts about the importance of speciation in small isolated populations.