Chapter 4: Interrelation through Similarity
Section I: Similarities Among The Species
One of the reasons to believe about the interrelation of all species is the astounding amount of similarities between them all, which this chapter will be devoted to. By drawing comparisons between different forms of life, I hope to shine light on to the idea that such similarities could not have come about except with a direct interrelation between the species.
As Naturalists study the environment and try to classify different organisms into different categories, such as family, species, race, they are often met with problems. For instance, there are 182 British plants which are regarded as varieties of another species, and one Naturalist makes the claim that there are 251 forms which are varieties of another species, while another claims that there are only 112 forms which are varieties of another species -- these "doubtful forms" (as they may be called) are so closely related to their common progenitor, with only slight and varying differences, that they have baffled scientists as to whether they are their own species are related to another species. [*1] Several ornithologists believe that the British red grouse is a race of the Norwegian species while another believe it is related to a species peculiar to Britain. [*2] One German author has found twelve distinct varieties of the common Oak tree, which other Naturalists have classified as distinct species. [*3] The Naturalist Alphonse De Condolle examined 600 species of Oak trees, and concluded that only 200 of them actually fit the description of the term "species." [*4] To quote Darwin, "How many of the birds and insects in North America and Europe, which differ very slightly from each other, have been ranked by one eminent naturalist as undoubted species, and by another as varieties, or, as they are often called, geographical races!" [*5] Mr. G. H. Lewes remarks...
In mankind, the muscles, bones, and even the brain is constructed the same as it is in the lower animals. [*7] Just as mankind can become infected with hydrophobia, variola, the glanders, syphilis, cholera, herpes, among others, so can other lower animals, just as the medicines on humans have a similar effect on the lower creatures. [*8] To quote Darwin, "There appears to me a strong analogy between the same infection or contagion producing the same result, or one closely similar, in two distinct animals, and the testing of two distinct fluids by the same chemical reagent." [*9] One Naturalist observed that monkeys are liable to the same noninfective disease as humans are, such as apoplexy, inflammation of the bowels, and cataract in the eye. [*10] Monkeys are also known to have a strong taste for coffee, tea, and nicotine, as they have been observed to smoke cigarettes. [*11] One Naturalist observed how an African tribe captures wild baboons, by leaving out strong beer and capturing them while they are inebriated. The following morning, they are sick, and turn away in disgust when offered more beer, something not uncommon to humans. [*12] Darwin once remarked, "An American monkey, an Ateles, after getting drunk on brandy, would never touch it again, and thus was wiser than many men." [*13] Parasites, both internal and external, which infect mankind are known to also infect other mammals. [*14] When mankind is wounded, his wounds are healed in the same manner as other organisms, even when compared to such a low life form such as insects. [*15] The hands and the feet of humans, when in the womb, are the same form as other lower organisms when early in development, and to quote Professor Thomas Henry Huxley, "quite in the later stages of development that the young human being presents marked differences from the young ape, while the latter departs as much from the dog in its developments, as the man does. Startling as this last assertion may appear to be, it is demonstrably true." [*16] The processes of courtship to birth and nurturing the young are remarkably similar in humans as they are in the lowest of mammals. [*17] For a human fetus, like the fetus of a primate, the heart is a simple pulsating vessel and the os coccyx (or "tail bone") extends beyond the legs of the fetus. [*18] In embryos, certain glands, known as corpora Wolffiana, act similar to the kidneys of fish. [*19] Bischoff says "that the convolutions of the brain in a human foetus at the end of the seventh month reach about the same stage of development as in a baboon when adult." [*20] Professor Owen once remarked, "which forms the fulcrum when standing or walking, is perhaps the most characteristic peculiarity in the human structure"; [*21] yet Professor Wyman found "that the great toe was shorter than the others; and, instead of being parallel to them, projected at an angle from the side of the foot, thus corresponding with the permanent condition of this part in the Quadrumana." [*22] In the fifth metatarsal of the foot, there is a muscle known as the ossis metatarsi quinti, and just as it is present in humans, it as also present in anthropomorphous apes. [*23] Another similarity between humans and apes, to quote Charles Darwin, "Monkeys seize thin branches or ropes, with the thumb on one side and the fingers and palm on the other, in the same manner as we do. They can thus also lift rather large objects, such as the neck of a bottle, to their mouths." [*24] Yet, for some races of mankind that are still living in what some would call "savagery," their feet are developed in a manner closer to other primates, in that they are very well adaptated for scaling trees. [*25] And, a quote by the father of Natural Selection...
The similarities between organisms of this planet is undeniable. In fact, in the 1700's, Voltaire would write, "If I glance at the animal world, I find that all quadrupeds, and all wingless bipeds, reproduce their kind by the same process of copulation, and all the females are viviparous." [*27] In his book The Descent of Man, Charles Darwin would offer more evidences on the similarities of all life forms. He would write, "Man is liable to numerous, slight, and diversified variations, which are induced by the same general causes, are governed and transmitted in accordance with the same general laws, as in the lower animals." [*28] and also "His [mankind's] body is constructed on the same homological plan as that of other mammals. He passes through the same phases of embryological development. " [*29] The reaction to drugs of mankind and animals is very similar, as Darwin describes: "I gave, as instances, our liability to the same diseases, and to the attacks of allied parasites; our tastes in common for the same stimulants, and the similar effects produced by them, as well as by various drugs, and other such facts." [*30] Finally, he writes: "Every evolutionist will admit that the five great vertebrate classes, namely, mammals, birds, reptiles, amphibians, and fishes, are descended from some one prototype; for they have much in common, especially during their embryonic state." [*31]
*1. Origin of the Species, by Charles Darwin, 1859, Sixth Edition, chapter 2.