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

Evidence from nuclear Dna

If, as supporters of the African Eve hypothesis claim, there was a population movement of anatomically modern humans out of their place of origin in Africa resulting in total replacement of the previous hominid populations in Europe and Asia, this should be supported not only by mitochondrial DNA evidence but also by DNA evidence from the cell’s nucleus. However, in his analysis of the early African Eve reports, Templeton (1993, p. 65) said, “. . . there is no single set of assumptions that allows the mtDNA and nuclear data to be compatible with an out-of-Africa replacement hypothesis.”

One group of researchers (Breguet et al. 1990) looked at variation in the B locus of the gene for the human apoprotein. According to Templeton (1993, pp. 68–69), their detailed analysis led them to conclude that “Cauca-soid populations (located from North Africa to India) were closest to the ancestral genetic stock and that worldwide genetic differentiation at this locus is best explained by westward and eastward gene flow from this geographical region and not by a sub-Saharan origin.” For researchers like myself, who are operating from a perspective influenced by the ancient Sanskrit writings of India, which posit recurrent appearances of the human species (after planetary deluges) in the Himalayan region, this is quite interesting.

More recently, researchers have found yet another problem with the African origins theory. This problem involves the globin gene cluster in humans. A gene or part of a gene at a particular location on a chromosome may appear in several different forms called alleles. One individual will have one allele, and a second individual another allele. In analyzing globin alleles in various populations, authors of a recent textbook found that the observed degree of variation implied an age much greater than 200,000 years for modern human populations. Indeed, looking at another part of the globin gene cluster, the authors stated that “two alleles from a non-coding (and therefore neutral) region have apparently persisted for 3 million years.” They concluded, “To date, it is unclear how the pattern found in the globin genes can be reconciled with a recent African origin of modern humans” (Page and Holmes 1998, p.132). The globin evidence is consistent with Puranic accounts of extreme human antiquity.

Some researchers, considering the complexities surrounding genetic data, have suggested that fossils remain the most reliable evidence for questions about human origins and antiquity: “Unlike genetic data derived from living humans, fossils can be used to test predictions of theories about the past without relying on a long list of assumptions about the neutrality of genetic markers, mutational rates, or other requirements necessary to retrodict the past from current genetic variation . . . genetic information, at best, provides a theory of how modern human origins might have happened if the assumptions used in interpreting the genetic data are correct” (Frayer et al. 1993, p. 19). I agree that genetic evidence does not always trump archeological evidence. This means that the archeological evidence for extreme human antiquity documented in Forbidden archeology provides a much needed check on the rampant speculations of genetic researchers.

So where do we stand? The whole question of human origins, analyzed from the perspective of genetic evidence, mitochondrial DNA evidence in particular, is confusing. For example, some scientists say that a small population of the genus Homo arose from australopithecus about 2 million years ago in Africa. This population developed into Homo erectus , and then spread throughout Eurasia developing into Neandertals and Neandertal-like populations. About 100,000 years ago a small population of anatomically modern Homo sapiens emerged in Africa, and then spread around the world, replacing the earlier populations of Homo erectus and Neandertals, without mixing significantly with them (Vigilant et al. 1991; Stoneking et al.1986). These anatomically modern humans then developed in different regions of the world into the different races we see today. Other scientists, looking at the same genetic, archeological, and paleontological evidence, conclude that the different races of anatomically modern humans emerged simultaneously in different parts of the world, directly from the Homo erectus and Neandertal populations in those parts of the world (Templeton 1993). According to this idea, anatomically modern humans would have emerged in large populations over wide geographical areas, not in some small founder population confined to a small area. Another group asserts that there was a small initial population of anatomically modern humans, confined to a small geographical region. But this group holds that this population differentiated into the different racial groups we see today while still confined to this small geographical area. The racial groups then are supposed to have migrated out of this area and expanded their numbers in particular parts of the world (Rogers and Jorde 1995, p. 1). In short, there is considerable confusion about the genetic evidence and what it means.

Y Chromosome evidence

In the foregoing discussion about mitochondrial DNA, I briefly mentioned nuclear DNA, the DNA found in the nucleus of human cells and gave a few examples. Let us now look carefully at another example of such evidence—the Y chromosome.

Human beings have 23 pairs of chromosomes in the nucleus of each cell. One of these pairs of chromosomes determines the sex of the individual. The pair of sex chromosomes in females is made up of two X chromosomes (XX). The pair of sex chromosomes in males is made up of one X chromosome and one Y chromosome (XY).

So, how is the sex of a particular individual determined? The repro-ductive cells (sperm and eggs) are different than the other cells in the body. Nonreproductive cells have the full complement of 23 pairs of chromosomes, for a total of 46 chromosomes. But a sperm cell or egg cell gets only half that number, just one set of 23 chromosomes instead of

23 pairs of chromosomes. When the sperm and the egg combine, the full number of chromosomes (46, or 23 pairs) is restored. When an egg is produced in a female, it will always have an X chromosome, because in the female, the pair of sex chromosomes is always XX. So when the chromosome pair XX splits to form eggs, each egg will get one X chromosome. But in the male, the pair of sex chromosomes is XY. So when the pair splits to form sperm, some of the sperm will have an X chromosome, and others will have a Y chromosome. If a sperm carrying an X chromosome combines with an egg, the fertilized egg will have an XX pair of sex chromosomes, and the egg will develop into a female child. If a sperm carrying a Y chromosome combines with an egg, the fertilized egg will have an XY pair of sex chromosomes, and the egg will develop into a male child. The Y chromosome is passed down only from father to son. Females do not carry the Y chromosome.

Certain parts of a chromosome are subject to a process called recombination, whereby parts of one chromosome are exchanged with parts of another chromosome. But a large section of the Y chromosome is not subject to such recombination. Theoretically, the only changes that accumulate in this nonrecombining part of the Y chromosome would be random mutations. The Y chromosome is the male counterpart of the mitochondrial DNA, which is passed down only from the mother and is also supposedly not subject to variation other than random mutations. The Y chromosome can therefore be used in human origins research in just about the same way as mitochondrial DNA—as a molecular clock and geographical locator. Some researchers propose that just as there was an African Eve, there was also an African Adam, or, as some call him, a “Y-guy.” As we shall see, however, the conclusions that can be drawn from Y chromosome studies are not very perfect, and therefore some researchers view “Y-guy” as “a statistical apparition generated by dubious evolutionary assumptions” (Bower