Michael Cremo - Human Devolution - A Vedic Alternative To Darwin's Theory

Some (Thomson 1988, pp. 121–122) have proposed that early changes in development are obviously possible, simply because they have obviously occurred. This is a typical example of blind faith in evolutionary doctrine. Nelson (1998, p. 158) says: “Note that this position rests entirely on the assumption of common descent. There is little if any experimental evidence that ‘changes in early development are possible.’ I know of only a single example of heritable changes in metazoan cleavage patterns.” In other words, there is only a single experimentally verified example of a genetic change in the early development of an animal that has been passed on to its descendants. The change involves a mutation in the early development of the snail Limenaea peregra, which causes only the direction of the coiling of its shell to switch from right to left (Nelson

1998, p. 170, citing Gilbert 1991, p. 86) This is not a very significant change. It represents no new biological feature.

So today there is practically no experimental evidence that early changes in development can result in viable organisms with new features. Some scientists propose that although such changes are not possible in today’s organisms, they were possible early in the history of evolution, resulting in major changes in body plans. Foote and Gould (1992, p. 1816) suggest that this proposed early period of developmental flexibility was closed off hundreds of millions of years ago at the end of the “Cambrian explosion,” during which all major body plans now seen in living things supposedly emerged. After the Cambrian explosion there was “some form of genetic and developmental locking.” The proof of this, say Foote and Gould, is that no new major body plans have emerged since the Cambrian. Further, they say that we do not see today that creatures with major mutations in genes that control early development survive (Foote and Gould 1992, p. 1816). But this era of early plasticity of body plans, generated by changes in early developmental stages of the embryo, is purely speculative. Scientists cannot point to any specific reason, on the biomolecular level, exactly why Cambrian creatures could survive such major mutations.

Nelson (1998, p. 168) says: “Golden ages of evolution are postulated (e.g., the Cambrian explosion), in the complete absence of any mechanistic understanding, to accommodate the demands of a philosophy of nature that holds, in the face of abundant disconfirming evidence, that complex things come into existence by undirected mutation and selection from simpler things. Yet, however unlikely they may be, these golden ages of macroevolution are preferable by neo-Darwinists to taking at face value the demonstrable limits of organismal structure and function—for those limits imply the primary discontinuity of organisms one from another.” Discontinuity implies intelligent design of the separate species.

Scientists find it difficult to explain in any detailed way how these body plans (or Bauplans) came about from some common ancestor by evolutionary processes. Bruce Wallace (1984, cited in Nelson 1998, p. 160) tells of some of the problems involved in modifying a body plan: “The Bauplan of an organism . . . can be thought of as the arrangement of genetic switches that control the course of the embryonic and subsequent development of the individual; such control must operate properly both in time generally and sequentially in the separately differentiated tissues. Selection, both natural and artificial, that leads to morphological change and other developmental modification does so by altering the settings and triggerings of these switches . . . The extreme difficulty encountered when attempting to transform one organism into another but still functional one lies in the difficulty in resetting a number of the many controlling switches in a manner that still allows for the individual’s orderly (somatic) development.” It is like trying to transform a six cylinder engine into an eight cylinder engine while keeping the engine running through all the changes. Arthur (1987, cited in Nelson 1998, p. 170) says that “in the end we have to admit that we do not really know how body plans originate.”

What to speak of understanding how genes can govern major changes in body plans, to produce new organisms, scientists do not yet fully understand how genes direct the development of the body plan of any par-ticular species. R. Raff and T. Kaufman (1991, p. 336) speak of science’s “currently poor understanding of the way in which genes direct the morphogenesis of even simple metazoan structures.” Each human being starts as a single cell—a fertilized egg. The egg begins to divide into more cells. Each cell contains the exact same DNA, but the cells differentiate into various tissues and structures. How exactly this happens is not currently understood, even in very small multicellular organisms.

Some scientists believe that “homeotic” genes provide the answer to the specification of body plans and their development in an organism. In the late nineteenth century biologists noted that body parts of some animals sometimes grew to resemble other body parts. For example, in insects, an antenna might come to display the form of a leg (a condition called Antennapedia). Such forms were called homeotic. The prefix homeo means “like, or similar,” so a homeotic leg would be a body part that resembles a leg. In the twentieth century, the gene responsible for the mutation that causes Antennapedia in fruit flies was discovered and named antp . But the big question is not how a leg can grow in place of an antenna, but how such complex structures as legs and antennas came into existence in the first place—something not perfectly explained up to now by genetic researchers and developmental biologists.

Besides antp, there are other homeotic genes in the fruit fly, such as Pax-6, related to eye development. In 1995, Walter Gehring and his colleagues mutated Pax-6, causing eyes to grow on the antenna and legs of fruit flies. Pax-6 is similar in flies and mammals (humans included). Part of the gene (the DNA binding segment) is also found in worms and squids (Quiring et al. 1994). Researchers concluded that Pax-6 was “the master control gene for eye morphogenesis” and that it is universal in multicellular animals (Halder et al. 1995, p. 1792).

But Wells (1998, pp. 56–57) points out: “If the same gene can ‘determine’ structures as radically different as . . . an insect’s eyes and the eyes of humans and squids then that gene is not determining much of anything.” He adds: “Except for telling us how an embryo directs its cells into one of several built-in developmental pathways, homeotic genes tell us nothing about how biological structures are formed.”

In the case of the eye, evolutionists have to explain how this complicated biological structure arose not just once, but several times. Prominent evolutionists L. von Salvini-Palwen and Ernst Mayr (1977) say that “the earliest invertebrates, or at least those that gave rise to the more advanced phyletic lines, had no photoreceptors” and that “photoreceptors have originated independently in at least 40, but possibly up to 65 or more different phyletic lines.”

The Biological Complexity of Humans

The great complexity of the organs found in the human body defies evolutionary explanation. Darwinists have not explained in any detailed way how these organs could have arisen by random genetic variations and natural selection.

The eye

The human eye is one such organ of apparently irreducible complexity. The pupil allows light into the eye, and the lens focuses the light on the retina. The eye also has features to correct for interference between light waves of different frequencies. It is hard to see how the eye could function without all of its parts being present. Even Darwin understood that the eye and other complex structures posed a problem for his theory of evolution, which required that such structures arise over many generations, step by step. Darwin didn’t give a detailed account of how this happened, but pointed to different living creatures with different kinds of eyes—some just light sensitive spots, some simple depressions with simple lenses, and others more complex. He suggested that the human eye could have arisen in stages like this. He ignored the question of how the first light sensitive spot came into being. “How a nerve comes to be sensitive to light hardly concerns us more than how life itself originated” (Darwin 1872, p. 151; Behe 1996, pp. 16–18).