Based on a literal reading of Genesis, most "young-earth creationists" (YECs), believe that a violent global flood occurred only a few thousand years ago, and destroyed all land life on earth except the pairs of animals and eight humans aboard Noah's Ark. However, this position contradicts extensive scientific evidence, and many Biblical scholars interpret the Flood as a regional rather than global event (Morton, 1997), or regard it as an allegorical account.

Besides extensive geologic and paleontological evidence against a young Earth and recent global flood, YECs have a serious problem explaining the massive amount of genetic diversity seen in modern populations of humans and many land animals, if as they maintain, each Genesis "kind" was reduced to a pair of individuals (or at most seven individuals) that left the Ark only a few thousand years ago.

Let's first discuss genetic diversity in modern humans. Each individual person normally has only two alleles (possible variations for a gene) for a given gene. That's because each person can inherit only one allele per gene from each parent. This creates a serious problem for young-Earth advocates. According to Genesis 7:7, only eight human beings were on Noah's Ark: Noah and his wife, their three sons, and their sons' wives. This means that that the Ark family had among them at most ten different alleles for each gene locus (3 x 2 = 6 for the wives, plus 2 each for Noah and his wife--their sons would have received all their alleles from their parents). Even if we allow the remote possibility that all three of Noah's sons were adopted, and thus that all eight people on the ark were unrelated, each could have carried only 2 different alleles for each gene locus, and the entire ark family would have 2 x 8 = 16 alleles for each gene locus. The problem for YECs is that among modern humans, many genes have dozens or more possible alleles per gene. For example, the human leukocyte antigen complex has 59 different alleles (Ayala et al, 1993).

So where did all the additional alleles in the modern population come from? In mainstream science, such alleles are largely the result of evolution, whereby natural selection acting on mutations (including sometimes gene duplication as well as point mutations and "crossing-over" mutations) over of millions of years produces the new alleles. Strict creationists must account for these changes in only a few thousand years, despite the fact that studies of populations subject to severe genetic bottlenecks do not produce large and rapid changes, but the opposite, genetic stagnation and low diversity for thousands of years.

The problem becomes even more severe when one considers that only about a thousand years before the Flood (as most YECs interpret Genesis), the entire human genome resided in two individuals: Adam and Eve. Each of them could have had at most 2 alleles per gene, or 4 alleles per gene between them. This would also be the case if each "kind" of land animal was created as a single pair. Although the Bible does not clarify this, YECs insist that only two original humans were created.

The problem becomes still worse when animal life is considered. According to Genesis 7: 2-3 Noah was commanded by God to take on the Ark seven of each kind of clean land animal and bird, and two of every unclean animal. Although this appears to contradict Genesis 7:8 which indicates that "pairs" of each clean and unclean animals entered the Ark, in order to be generous and allow the most alleles, let's assume the first version is correct. This means that for clean animals, at most fourteen alleles are represented, and for unclean animals, four alleles. Since each species has tens of thousands of genes, and since many genes involve many alleles (sometimes dozens), the question must be asked again: where did all the alleles come from?

While some previous YECs such as Whitcomb and Morris (1961) or (Woodmorappe, 1996) suggested that a "kind" was roughly equivalent to a genus, a growing number of modern creationists suggesting (evidently to lessen burdens on the Ark) that Genesis "kinds" are even broader. Indeed, the AIG authors are now reviving what George M Price suggested decades earlier (Price, 1924) -that a "Genesis kind" or "baramin" is roughly equivalent to a taxonomic "family," or in some cases, even an order.

However, this only exacerbates the problem, as it requires even more alleles be generated (that is, evolve) after the Flood. Indeed, some genera consist of dozens or even hundreds of modern species, with scores of alleles for gene loci they shared in common. In other words, if a pair of animals representing a genus were taken on the ark, YECs would need to account for vast numbers of new alleles within many new species within a few thousand years or less (according to some recent YEC articles, only a few hundred years).

Creationists often claim that evolution cannot produce any new genetic information, but in view of the above considerations, many thousands of new alleles must have arisen primarily through mutations and natural selection, which constitutes "new information" and "evolution" by any reasonable definitions. In fact, to account for the large numbers of alleles seen in current populations from the very limited ones at the presumed time of the Creation or Flood, would require more dramatic and rapid evolution than even mainstream scientists allow.

Proposed Mechanisms for "Hyperspeciation" (HS)

Furthermore, YECS disagree contradict each other (and sometimes even themselves) on what if any role mutations and natural selection were involved in hyperspeciation (HS). A long paper by AIG author Nathaniel Jeanson (2016a) cites mutations, natural selection, and genetic drift as possible mechanisms for HS (Jeanson and Lisle, 2016) --the same mechanisms that mainstream scientists have long cited as major factors in evolution. However, in another AIG article entitled "Did Natural Selection Play a Role in Speciation" he seems to imply the opposite, that the answer is "no." Instead suggests that only hybridization and initially created variation or "heterozygosity" is needed, which not only appears to contradict his longer article, but fails to explain how, without natural selection, variations would be inherited or help organisms adapt to changing environments, let alone rapidly form new species. Moreover, he seems to forget that no matter how much variation was contained among organisms at Creation or before the Flood, after the Flood all animals would have at most four alleles per trait --a horrendous genetic bottleneck (discussed further below).

The common YEC belief in a single "ice age" exacerbates these chronological difficulties. As David MacMilian (2015) notes: "... they are running out of time. Creationists believe in an Ice Age which ended about 700 years after the global flood, at which point most modern species most modern species would have had to already emerge. They must already propose an [exponentially rapid burst of evolutionary speciation evolution following Noah's flood; there is no way they can fit a full 40 million years of adaptation and speciation into the 200-odd generations that would have spanned this period."

MacMilian (2015) also notes that AIG's "Ark Encounter" museum displays entail a number of serious inconsistencies and paradoxes, and that if the implications of their charts and diagrams are taken to their logical extensions, they would need to accept evolution beyond the family level, but apparently their commitment to YECism and Biblical literalism prevents them from doing so.

Jeanson and Lisle (2016) present many large charts and graphs showing mutation rates in various taxa, implying that they support their hyper-speciation claims. However, such data seems largely moot unless they can show what percentage of the mutations are selected and inherited. Indeed, they need an extremely high percentage to produce hyper-evolution. They have not done this, nor explained such a high level of selected mutations would be achieved. Moreover, appealing to mutations and natural selection to support hyper-speciation notions appears to starkly contradict the frequent YEC claim that mutations are almost always harmful, and that natural selection is largely limited to eliminating negative traits rather than producing new and useful ones.

In summary, YECs have several major problems accounting for the vast genetic diversity seen in today's animal and human populations, besides all the additional diversity evidenced in the fossil record. YECs have not demonstrated that speciation can occur at rates anywhere close to that required in a post-Flood/YEC timeframe. They cannot identify any plausible mechanism to limit speciation, and thus cannot explain why "micro-evolutionary" changes would not accumulate into macro-evolutionary changes. Indeed, their hyper-speciation claims conflict with multiple aspects of the fossil record, which show significant evolutionary change, but over long periods of time. Their claims also conflict with evidence from population biology and genetics, and their own past assertions about the roles of mutations and natural selection in speciation. Ironically, an AIG website article by John Sanford (2014a) praises his own book Genetic Entropy as "tremendous" (Sanford, 2014b), even though it and argues that natural selection does not improve species fitness, that genomes are continually deteriorating, and that new genetic information is never created --exactly the opposite of what YECs need to support their hyper-speciation claims. Many other problems in YEC claims about hyper-speciation and the origin of animal diversity are provided in a series of articles by Joel Duff (2017b).

Conclusions

References

Ayala, F.J. et al. 1993. MHC polymorphism and human origins. Scientific American 269(6):78-83.

Duff, Joel, 2017a. Walking Whales On Board Noah's Ark: The Inevitable End-point of Creationists' Post-Flood Hyper-Speciation Belief? Web article at: https://thenaturalhistorian.com/category/blog/

Duff, Joel, 2017b. YEC Hyper-speciation Archive. "Natural Historian" website menu at: https://thenaturalhistorian.com/yec-hyper-evolution-archive/

Jeanson, Nathaniel T., and Lisle, Jason, 2016. On the Origin of Eukaryotic Species' Genotypic and Phenotypic Diversity. Answers in Genesis web article at: https://answersingenesis.org/natural-selection/speciation/on-the-origin-of-eukaryotic-species-genotypic-and-phenotypic-diversity/

Jeanson, Nathaniel, T. 2016b. Did Natural Selection Play a Role in Speciation? How Species Arose after the Ark. AIG article at: https://answersingenesis.org/natural-selection/speciation/did-natural-selection-play-a-role-in-speciation/

MacMillan, David S, 2015. Dodging Darwin: How Ken Ham's Ark Encounter is Slowly Embracing Evolution December 30, 2015. Web article at: https://thenaturalhistorian.com/2015/12/30/dodging-darwin-how-ken-hams-ark-encounter-is-slowly-embracing-evolution/

Morton, Glenn. 1997. Why the Flood is Not Global. Web article at: http://home.entouch.net/dmd/gflood.htm

O'Brien, S. J., 1985 (Mar 22). Genetic basis for species vulnerability in the cheetah. Science. Vol. 227, Issue 4693, pp. 1428-1434. Web version at: https://msu.edu/course/zol/445/OBrien%20cheetah%20Science%201985.pdf

Price, G.M. 1924. The Phantom of Organic Evolution. Fleming H. Revell, New York, NY.

Sanford, John C., 2014a. Genetic Entropy. AIG website article at: https://answersingenesis.org/store/product/genetic-entropy-mystery-genome/?sku=10-3-114

Sanford, John C., 2014b. Genetic Entropy. FMS Publications. 270 pages. ISBN: 9780981631608. Reviewed by AIG at: https://answersingenesis.org/store/product/genetic-entropy-mystery-genome/?sku=10-3-114

Vuletic, Mark I., 2007, From "Defenders Guide to Science and Creationism" website at: http://www.vuletic.com/hume/cefec/4- 7.html

Whitcomb, John C, and Morris, Henry M. 1961. The Genesis Flood. John C. Whitcomb and Henry M. Morris. Presbyterian & Reformed Publishing.

Wood, Todd, 2002. The Ageing Process: Rapid Post-Flood Intrabaraminic Diversification Caused by Altruistic Genetic Elements (AGES). Origins, No. 54. On line edition available at: www.grisda.org/origins/54005.pdf

Woodmorappe, John, 1996. Noah's Ark: A Feasibility Study. El Cajon: Institute for Creation Research.

------------ For more information on the inheritance of human eye colors, see: http://en.wikipedia.org/wiki/Eye_color

Genesis 7 (NIV):

1 The LORD then said to Noah, "Go into the ark, you and your whole family, because I have found you righteous in this generation. 2 Take with you seven [a] of every kind of clean animal, a male and its mate, and two of every kind of unclean animal, a male and its mate, 3 and also seven of every kind of bird, male and female, to keep their various kinds alive throughout the earth. 4 Seven days from now I will send rain on the earth for forty days and forty nights, and I will wipe from the face of the earth every living creature I have made." 5 And Noah did all that the LORD commanded him. 6 Noah was six hundred years old when the floodwaters came on the earth. 7 And Noah and his sons and his wife and his sons' wives entered the ark to escape the waters of the flood. 8 Pairs of clean and unclean animals, of birds and of all creatures that move along the ground, 9 male and female, came to Noah and entered the ark, as God had commanded Noah. 10 And after the seven days the floodwaters came on the earth. -------