The Dating Gap
by Marvin L. Lubenow, M.S., Th.M.
Evolution places severe demands upon fossils used to support it. A fossil in an evolutionary sequence must have both the proper morphology (shape) to fit that sequence and an appropriate date to justify its position in that sequence. Since the morphology of a fossil cannot be changed, it is obvious that the dating is the more subjective element of the two items. Yet, accurate dating of fossils is so essential that the scientific respectability of evolution is contingent upon fossils having appropriate dates.
Popular presentations of human evolution show a rather smooth transition of fossils leading to modern humans. The impression given is that the dating of the individual fossils in that sequence is accurate enough to establish human evolution as a fact. However, because of severe dating problems which are seldom mentioned, this alleged sequence cannot be maintained. To present the fossil evidence as a relatively smooth transition leading to modern humans is akin to intellectual dishonesty.
It is impossible to give an evolutionary sequence to the human fossils because there is a coverage gap involving the dating methods which evolutionists believe are the most reliable—radiocarbon and potassium-argon (K-Ar). This gap is from about 40,000 ya (years ago) to about 200,000 ya on the evolutionist's time scale. It covers roughly the period known as the Middle Stone Age (MSA). This coverage gap lies beyond what is considered the effective range for radiocarbon and prior to what is considered the effective range for potassium-argon. This problem period may be even larger because: (1) some dating authorities believe that the effective range for K-Ar doesn't begin until about 400,000 ya, and (2) many of the older fossils are found at sites that lack the volcanic rocks necessary for K-Ar dating and hence cannot be dated by this method at all.
Although young-earth creationists challenge the legitimacy of all of the dates obtained by the long-term radiometric methods, even evolutionists are beginning to admit that this dating gap presents a problem for them. However, the real seriousness of this problem seems to elude them, even when they occasionally refer to it in their writings.
In the past 15 years, the major focus of human evolution has shifted from the origin of "all" humans to the origin of "modern" humans, and the very time during which modern humans are alleged to have evolved from their more primitive human ancestors is the period covered by this gap. At least 406 human-fossil individuals are placed by evolutionists in this 40,000-to-200,000 ya time-period gap and hence are questionably dated. The inability of the radiocarbon and the K-Ar methods to cover this time period explains why many alternate dating methods have been devised to attempt to give coverage in this area. However, these alternative methods have serious problems of their own.
Of the 84 anatomically modern Homo sapiens fossil individuals dated by evolutionists beyond 40,000 years, 59 of them (70%) fall into this 40,000-to-200,000 ya gap. (Anatomically modern Homo sapiens fossils that are dated more recently than 40,000 years of age are not of great significance for evolutionary purposes and are not under consideration here.)
There are four Neanderthal fossil individuals that are dated more recently than 40,000 years. They are the Amud I and Shukbah remains from Israel and the Saint-Cesaire and Arcy-sur-Cure remains from France. All other Neanderthal remains, some 300 fossil individuals, or approximately 98.6% of all of the Neanderthals, fall into the period covered by this gap. (It is well known that another reason why many of the Neanderthal fossils are poorly dated is because they were found long before the importance of documenting fossils in their geological context was fully appreciated.)
The relatively new fossil category created by evolutionists, the "archaic Homo sapiens" category, contains at least 64 fossil individuals. Twenty-eight of them (44%) fall within this time gap. Nineteen of the 222 Homo erectus fossil individuals (9% of the total) likewise fall into this time gap. In all, 406 human-fossil individuals which evolutionists feel are crucial in documenting the evolution of modern humans fall into the gap between radiocarbon and K-Ar dating and hence have uncertain ages.
Creationists have noted an interesting pattern in evolutionist writings regarding the dating of fossils. Shortcomings of a dating method in current use are not generally acknowledged by evolutionists. Only when they feel they have devised a better method for a specific time period, do they publicly admit the weaknesses of the method they had been using previously. The result is that the public assumes the dating methods used at any given time are adequate, whereas the dating specialists working with those methods know that this is not necessarily the case.
The latest illustration of not admitting the uncertainties of older dating methods until newer ones have been developed centers around a new method proposed for dating human fossils in this 40,000-to-200,000-years ago time period. This new method, announced in the journal, Science, involves racemization of amino acids in ostrich eggshell. The amino-acid method was developed some time ago for dating bone material at archaeological sites. Because bone is porous, it is subject to ground-water leaching. Hence, the method fell into disfavor because it gave questionable dates. However, because ostrich eggshell is thought to be a rather closed system, it is claimed that items found in association with it can be dated more accurately by the amino-acid-racemization method.
The admissions now being made about the dating methods that have been previously used by evolutionists to cover this time period are particularly interesting. These admissions have profound implications for human evolution. In the Science article on ostrich-eggshell dating, the authors state that many of the dates assigned to human fossils in this 40,000-to-200,000-years ago period based on the older methods were only "provisional," and that all such dating is "uncertain." These are remarkable admissions. Anyone familiar with the paleoanthropological literature knows that this is not the way most of the dates for fossil discoveries in that time period have been presented. This time period is critical for human evolution, and evolutionists have consistently claimed a degree of certainty in their dating which now appears to be unjustified.
The author does not wish to imply that the ostrich-eggshell-dating method is a legitimate one. The point is that, for evolutionists to claim they now have a "better" method for dating human fossils discovered in the future does not correct the inaccurate dates of human fossils that were discovered in the past. The dating flaws of the past cannot be rectified because: (1) many of those fossil sites have been destroyed or altered, so that reconstruction to allow for redating of fossils after the fact is not possible; and (2) to find ostrich eggshell that can be shown to have been in unquestioned association with those previously discovered fossils is virtually impossible.
The uncertainty of fossil dates in the Middle Stone Age is just the tip of the iceberg. For evolutionists, the problem is far more serious, but few are willing to acknowledge it. William Howells (Harvard University) states that the dating problems involve the entire Middle Pleistocene (100,000 to 700,000 ya, according to evolutionists). This would involve many more fossils than just those in the Middle Stone Age. Howells writes: "It cannot be too strongly emphasized how much uncertainty attaches to placement of all but a few of the fossils, absolutely or relatively, especially for the Middle Pleistocene." Creationists recognize that the problem is far greater than even Howells suggests. But it is refreshing to know that some evolutionists are speaking frankly about the dating problems involving the human fossils.
Human evolution demands precise dating of the relevant fossils. Evolutionists now admit that the dates for the human fossils in the significant Middle Stone Age period and elsewhere are uncertain. It means that there is no such thing as a legitimate evolutionary fossil sequence leading to modern humans. It also means that evolutionists cannot make accurate statements regarding the origin of modern humans based on fossils discovered thus far. Their continuing to do so reveals that their statements are based on a belief system, not on the practice of a rigorous science.
- Richard G. Klein, The Human Career: Human Biological and Cultural Origins. (Chicago: University of Chicago Press, 1989): 254, 292.
- For charts listing all of the fossils in this time period, see Marvin L. Lubenow, Bones of Contention. (Grand Rapids: Baker Book House, 1992)
- A. S. Brooks, P. E. Hare, J. E. Kokis, G. H. Miller, R. D. Ernst, and F. Wendorf, "Dating Pleistocene Archaeological Sites by Protein Diagenesis in Ostrich Eggshell," Science 248 (6 April 1990): 60-64.
William W. Howells, Homo erectus:—Who, When, and Where: A Survey,
"Yearbook of Physical Anthropology" 23, 1980
(Supplement 1 to the "American Journal of Physical Anthropology"): 8.
* Professor of Bible and Apologetics at Christian Heritage College in El Cajon, California.
Cite this article: Marvin L. Lubenow, M.S., Th.M. 1993. The Dating Gap. Acts & Facts. 22 (10).