Teaching Evolution - Is There a Better Way?
1. Today's public school textbooks on Biology, Earth sciences, and Human society generally well-present the facts; it is the interpretation of those facts that is currently under fire and is being openly questioned. Without exception, that interpretation is from the evolutionary perspective and serves to colour the very words that are used in the text. Textbooks on Human anthropology are notoriously bad in this repect. However, this presentation is concerned especially with the slim chapter present in virtually every Biology textbook and usually titled "The Evidences for Evolution." The subtitles in these notes will be recognizable in most Biology textbooks.
2. Fossils & the Geologic Column. The text tells the student that fossils of simple life forms are found in the lowest strata of sedimentary rock (the Cambrian) then they become more complex as the strata become more recent. Usually, there is a diagram with illustrations of sea-bed life forms at the bottom then in rising order: fishes, amphibians, reptiles, mammals and man at the top. Textbooks may intend this hypothetical diagram, the geologic column, simply to indicate the life forms typical of each era of earth's history but the reader would naturally perceive this to be the evidence that those life forms did indeed develop in this order. This circular projection is then reinforced when the textbooks also claim this fossil order to be the most powerful evidence for evolution. Historically, it was assumed that life evolved from simple to complex, selected fossil evidence seemed to confirm this, but more often than not the fish, the amphibian, reptile etc were out of order or missing. In recognition of this, more than 150 years ago, geologists began using "index fossils," a series of marine arthropods, crustaceans, brachiopods, molluscs etc all of which are very small but their order was more consistent and, again, this was their assumed order of apearance; many of them still exist today. It is the index fossils that are used to identify the strata. The dating of the strata was initially based upon an assumed rate of deposition of sediment resulting in millions of years for massive beds; claims that radiometric methods confirm these ages are regarded as secondary evidence by geologists. It is now openly admitted that naming and dating rocks by fossils and the fossils by the rocks is mere circular reasoning based upon the assumptions that life appeared in the sequence, simple to complex and the assumed of rates of deposition. When index fossils are found out of order, geologists speak of the strata as an "unconformity" i.e. it does not conform to the theory. In the last decade or so it has been admitted that representatives of every phylum are found fully formed at the Cambrian level (the "Cambrian Explosion") followed by degradation and extinction indicating "bottom-up" regression not Darwinian progression. David. Kitts. Evolution, 1974, 28:467; Niles Eldredge. Time Frames, 1985, p.52; Tom Kemp. New Scientist, 1985, 108:67; R.H.Rastal. Encyclopedia Britannica 15th ed. 10:168; R. Dawkins. The Blind Watchmaker, 1987, p.229; Mark McMenamin. Palaios, 1990, 5:1.
3. Homology. The bones of the forelimbs of the bat, the horse, and the human are shown to emphasise their similarity. Darwin called such organs homologous and explained that they had resulted from common ancestry or descent. The definition of homology is given as similar structures that result from common ancestry but first it must be decided that there was a common ancestor. For example, the octopus eye and the human eye are very similar yet these are not regarded as homologous because the octopus and the human are not believed to have a common ancestor. But, having decided that two similar-looking limbs are homologous, it is then argued that this similarity proves their common ancestry! This is nothing more than circular reasoning. Darwin lamented that the absence of intermediate fossils was the weakest part of his theory and this is still echoed by senior paleontologists today. The fossil record shows no sign of gradual change as fin changes to leg or limb to wing and in any case such transition creatures would quickly be excluded since, a partially formed wing, would render the creature less fit to survive. Yet, textbooks repeatedly claim that, "more and more missing links have been found" while the Archaeopteryx is the example always cited. This is the alleged transition between the dinosaur and the bird. It was controversial when discovered in 1861, is still the subject of controversy and not accepted as a transition by every paleontologist. Claims for more recent discoveries of Archaeopteryx are found to be nothing more than existing museum specimens re-classified as Archaeopteryx. Every alleged ape-to-man fossil has been wreathed in controversy, nevertheless, they invariably serve as textbook examples for a decade or two until others quietly take their place. Gail Vines. New Scientist, 1985, 105:3; G. P. Wagner. Annual Review of Ecology & Systematics, 1989, p.51.
4. Vestigial Organs. The so-called vestigial organs are cited as evidence for the "common ancestor," and either the boa constrictor's or the whale's "legs" are given as examples. Two very small bones found half-way along the vertebrae are said to be homologous to the hip bones of other vertebrates. The explanation is actually a tautology based upon the assumption that whales and snakes evolved from four-legged ancestors; this is then offered as evidence that this did in fact occur. In the nineteenth century it was claimed that human beings had 180 vestigial organs but these have quietly disappeared as medical knowledged has advanced. Today, some textbooks will only offer the human "tail," sometimes found in the newly-born as evidence but medical science knows this is a caudal appendage having no relationship whatsoever to the vertebrae. D. R. Scadding. Evolutionary Theory, 1981, 5:173; Steven Stanley. Earth & Life Through Time (Textbook), 1989, p.138; J. K. Rijsbosch. The Netherlands Journal of Surgery, 1960, 12:211.
5. The Peppered Moths. In 1959 Bernard Kettlewell published his work on the peppered moth as the "consummation and confirmation" of evolution. His work, and the famous photograph of the black and white forms of this moth on the lichen-covered trunk of a tree, have appeared in virtually every biology textbook as definitive evidence of evolution. The story began in England at the time of the Industrial Revolution where it was noted that as the tree trunks became blacked by industrial soot, the white form of the moth, Biston betularia, declined in numbers while the black form proliferated. Later in this century, when anti-pollution laws were introduced, the tree trunks became white and the moth population shifted back from predominately black to white. Kettlewell believed that the birds ate those moths that could easily be seen as they rested on the tree trunk. This shift in population was real but to this day no one really knows the mechanism. As early as 1975 doubts were expressed in Kettlewell's explanation because it was known that there were major problems but nothing was said in the textbooks. In 1998 Michael Majerus published a scholarly work titled Melanism: Evolution in Action in which these problems were spelled out.The birds were not the principal predator since they fly during the day when the moths are well hidden and researchers do not know where they hide. The moths do not rest on tree trunks but the famous photograph of the black and white varieties was produced by gluing dead specimens to a tree trunk. The same population shift has occurred in an identical population of moths in Michigan where there had been no industrial pollution and Kettlewell's work is now highly suspect. Kettlewell and other workers since have simply observed a shift in population. When insecticides such as DTD were developed it was recognized that, say, 99% of the insect population was affected. This was seen to be commercially viable and, although at first successful, like the peppered moths, that resistant 1% has now become dominant. This is simply natural selection but is not speciation. Theo. Sargent et al. Evolutionary Biology, 1998, 30:299ff.; Larry Witham. The Washington Times (National Weekly ed.) Jan. 25, 1999, p.28.
6. Darwin's finches (Geospiza). There are 13 varieties of this bird found on the Galapagos Islands. Textbooks today still claim these finches were the source of Darwin's inspiration, however this was a legend introduced by Percy Lowe in 1936 and exposed in the 1982. The finches probably did originate from one mating pair blown from the mainland while adaptation to the environment has caused slight changes in the size and shape of the beak. Darwin called this "Natural Selection" and initially (1859) claimed it was the mechanism that produced new species. Later, he conceded that natural selection was only part of the mechanism for evolution. The facts have been established by Peter and Rosemary Grant who observed natural selection produce larger beaks in one drought season but also smaller beaks in one wet season. There is little evidence of speciation since it was observed that most of these finches hybridize with fertile offspring resulting in what is known as oscillating divergence and convergence of the population. Darwin experimented with pigeons and it was evident to him that there is far greater variation among pigeons than among the finches and no one claims that the pigeons have speciated. Frank Sulloway. Journal of the History of Biology, 1982, 15:1-53; Peter & Rosemary Grant. Proc. Roy. Soc. of London B, 1993, 251:111 and Science, 1992, 256:193; Charles Darwin. On the Origin of Species, 1859, Chap.1.
7. Embryology. Here it is claimed that during embryonic development the embryo passes through many of the prior evolutionary stages thus by circular reasoning this becomes the evidence that evolution has taken place. Promoted by Ernst Haeckel in 1866 as his "Biogenetic Law" or "Recapitulation Theory" and popularised by his phrase "Ontogeny recapitulates Phylogeny," it was condemned in 1874 as fraudulent by Wilhelm His, a noted embryologist. In spite of this, Haeckel's nineteenth century engravings showing the parallel developments of the fish, the salamander, the tortoise, the chick, the rabbit and the human appears in most biology textbooks to this day. It is sometimes claimed that in its early stages the human has gills like a fish and a heart like a frog and is a popular argument to justify abortion, however, embryologists point out that the pharyngeal arches and clefts found in many developing embryos have nothing whatsoever to do with gills. Embryonic development is said to be evidence for the common ancestor yet even the 15th ed. of the Encyclopedia Britannica, 2:221 says: "[it] was influential ...but has been of little significance in elucidating either evolution or embryonic growth." Haeckel had taken liberties in three directions: he selected only those creatures who came closest to fitting his theory i.e. their embryos looked vaugely similar; he distorted his drawings to make them appear more alike than they really are and he completely omitted the earliest embryonic stages that look noticeably different. For example, he had made the eye of the dog twice as large to match that of the human and doubled the length of the lower vertebrae of the human to match the tail of the dog. As bad as this was, a further scandal came to light in 1997. Professor Michael Richardson published a paper containing a series of photographs showing that the early embryonic stages of the fish, the salamander, the tortois etc. i.e. the top horizontal array of embryos, were not at all the look-alike embryos Haeckel had drawn. New Scientist (Sept.6, 1997) declared this news as "Embryonic Fraud Lives On." But, the establishment had clearly been rattled because, incredibly, Richardson issued a letter five months later in Science (May, 1998) to say that "the principle underlying Haeckel's drawings does not negate Darwinian evolution ..." William Ballard. Bioscience 1976, 26:36; Michael Richardson(7 authors). Anatomy & Embryology, 1997, 196:91; Elizabeth Pennisi. Science 1997, 277:1435.
8. A Proposal. Although unstated, traditional teaching assumes a progressive increase of genetic information as molecule becomes man. The evidences offered by textbooks in support of this progression and discussed here can hardly be considered convincing while other evidences such as the origin of life experiments or the evolution of the horse are equally as dubious. Students familiar with the Internet are becoming aware of these deficiencies and, if not confused, are left skeptical. A suggested alternative is to consider a progressive decrease of genetic information. The fossil evidence supports it: Life, much the same as it is today, began suddenly in the Cambrian era and has adapted, degenerated or become extinct. Adaptation can occur quickly permitting considerable variation within the limits of the species but loss of genetic information is a known continuing process (e.g.telemeres); this eventually leads to intersterility within the species but it is not speciation. The horse and the donkey, tiger and lion, sheep and goat or camel and llama were likely single species but with domestication or isolation have become intersterile. Alternatively, the wolf, fennec, fox, coyote, colishe, jackal and domestic dog are all interfertile thus have not speciated even though they have been given separate species names. It would be an instructive and insightful exercise to ask students to consider or to list actual evidences that support either progressive acquisition or progressive loss of genetic information.
Photo: Charles Darwin in 1854.
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