A little more than 10 years ago molecular biologists believed that they had found evidence in human genes that all people share a common female ancestor, dubbed Eve, who lived in Africa about 200,000 years ago. The claim has seemingly been challenged on both genetic and fossil evidence, and it had been supported by a repetition of the same kind of analysis. There is an argument that one would expect all current humans to have one common ancestor based on sampling statistics alone.
Then comes corroboration from a different kind of genetic study. While the earlier claim was based on DNA transmitted only through the maternal lineage (mitochondrial DNA), the new report uses DNA transmitted and possessed only by males (the Y chromosome). Michael F. Hammer, a researcher in molecular evolution, reported that his analysis of a part of the Y sex chromosome indicates that modern humans descended from a common male ancestor who lived 188,000 years ago. Although the new report does not say where that ancient man, whom some are calling 'Adam,' lived, his age is close enough to Eve's for this kind of work.
Both analyses are based on counting mutations that distinguish a portion of one modern person's DNA from that of others and using a "molecular clock" that assumes the mutations arise at a known, constant rate.
Even though the studies refer to a single man or woman in the past, they do not imply that those people were a couple or even that they were the only parents of all humans. Their primary significance is in pointing to the time when anatomically modern human beings, Homo sapiens sapiens, evolved from a more primitive ancestor, generally thought to be an archaic form of humans. Many experts propose that the founders of the modern species numbered around 10,000.
Many anthropologists believe this transition happened in Africa and that the subspecies spread to other parts of the world, replacing more primitive forms of humans such as Homo erectus. Others, however, dispute the genetic evidence and argue that modern people evolved in many parts of the world as products both of the people already living there and of immigrants.
There is evidence for this contrary view in fossils. In 1992, for example, researchers found skulls in China that appeared to blend traits of Homo sapiens and the ancestral species, Homo erectus. The skulls are from hominids who they say lived nearly 400,000 years ago, suggesting the transition was happening long before "Adam' or "Eve' could have lived?
Lucy
Evolutionary or phylogenetic relationships for the hominids are proposed by comparing anatomical features of specimens found in the fossil record and those of still existing species. The available hominid fossils in most cases are partial crania, partial jaw bones, isolated teeth, and infrequently partial upper and lower limbs. Rarely do paleoanthropologists find a complete cranium, let alone a nearly complete skeleton. Typically a hominid species is defined by just a few bone fragments, and many times the remains have been crushed and shattered and damaged prior to fossilization and afterwards deformed by geological processes. Recently two researchers took a look at the reliability of phylogenic analysis by comparing proposed characteristics obtained from gene and protein sequences and those obtained from analysis of cranial and dental features for two currently existing groups of primates, the hominoids (gorillas, chimpanzees, and humans) and the papionins (baboons, mangabeys, and mavcaques). In both cases the molecular phylogenies differed significantly from those derived using cranial and dental characteristics. The researchers concluded that crainodental characteristics cannot be used as reliable indicators of existing primate species evolutionary relationships. "Without a reliable phylogeny, little confidence can be placed in the hypotheses of ancestry..." (Mark Collard and Bernard Wood, "How Reliable Are Human Phylogenetic Hypotheses?" Proceedings of the National Academy of Sciences USA 97 (2000) 5003-6)
Confidence in genetic approaches to this problem should also be tempered by another report. Three British geneticists, led by L. Simon Whitfield, carried out analysis of both mitochondrial DNA and Y chromosome DNA from the same people. The mitochondrial data yielded a time of origin of modern humans between 120,000 and 474,000 years ago. The Y chromosome data indicated the origin was probably between 37,000 and 49,000 years ago. And two more Y chromosome studies using newer techniques and larger sample sizes were reported in "Proceedings of the National Academy of Sciences USA 97 (2000)": report numbers 7354-59 and 7360-65 and they add more evidence for the younger dates. They both support a 50,000 year ago origin for humanity. They also seem to point to a rapid population expansion around 28,000 years ago.
"However, the 50,000 year time may be too long, and the true time may be about 36,525 years, which rounds off to 40,000 years, because it has been shown by Awadalla, Eyre-Walker, and Smith, in Science 286 (24 December 1999) 2524-2525, that "... The assumption that human mitochondrial DNA is inherited from one parent only and therefore does not recombine is questionable. Linkage disequilibrium in human and chimpanzee mitochondrial DNA declines as a function of the distance between sites. This pattern can be attributed to one mechanism only: recombination. ... Many inferences about the pattern and tempo of human evolution and mtDNA evolution have been based on the assumption of clonal inheritance. These inferences will now have to be reconsidered."" (Were Adam and Eve Africans?)
Conclusion: While the results of chromosome research is incredibly exciting, it is still in its infancy and often the findings are overly publicized as is unfortunately often necessary to obtain funding for further research. Hopefully in the future these researchers will consider the true accuracy of their results and will truthfully report their findings without biasing their results by other theories and theological beliefs. We feel that further more accurate research will probably result in more recent dates than any of those discussed above. As has been concluded about one mitrochondrial study, "Many scientists are quite skeptical of the estimated date, ... caution that the mitochondrial clock is none too reliable. "The date is very dubious--it's 135,000 years plus or minus about 300% ..." (from http://web.raex.com/~kitten/origin.htm)
Know therefore that the Lord thy God,
he is God, the faithful God,
which keepeth covenant and mercy with them that love him
and keep his commandments to a thousand generations;
(Deuteronomy 7:9 KJV)
Many scholars have interpreted the Hebrew words translated as "thousand generations" as "a proverbial expression meaning endlessly or forever" and not to mean a literal thousand generations. For the word translated as generations is more properly translated as "a revolution of time" or can also be "an age" as well as a generation. However, possibly one should reconsider that the translation as a literal "thousand generations" is also appropriate, much like for many centuries many "scholars" ignored the translation of "he that sitteth upon the circle of the earth" in Isaiah 40:22 as an indicator that possibly the earth was round.
Source: http://www.accuracyingenesis.com/eve.html
