Creationists disagree on the extent of Noah’s Flood. The main reason young-earth creationists insist the Flood was a global event is their model demands it. The Flood is the mechanism they use to explain the earth’s geological features. Rather than forming over millions or billions of years as most scientists believe, young-earth creationists maintain the earth’s features are the result of global floodwaters and processes that accompanied the Flood, like erosion, volcanism and tectonics.1 They also attribute the majority of the fossil record, virtually everything below the Tertiary strata, to the Flood.2
One problem for the global-Flood view is explaining how the earth was repopulated with land animals after the Flood. Young-earth creationists who recognize the problem of fitting all the land animals on the ark now conclude Noah only took pairs of the Genesis "kinds." These, they say, were the ancestral seeds God provided to repopulate the world. As the "kinds" left the ark, they gave rise to the many different species on Earth today. For example, horses, zebras and donkeys descended from an equine "kind," dogs, wolves, coyotes and jackals from a canine "kind," and cattle, bison and water buffalos from a cattle "kind."3
If true, the amount of post-Flood speciation must have been staggering. Young-earth creationists estimate Noah took 8,000 to 20,000 species on the ark. They also say a significant number of these species went extinct shortly after the Flood.4,5 Based on their dating method, approximately 7 million species have existed since the Flood–about 2 million have gone extinct and 5 million are alive today. Therefore, nearly 7 million species must have arisen from far less than 20,000 species in a time frame of a few hundred years.6
How could new species have appeared so fast? Young-earth creationists say the "kinds" on the ark had a built-in capacity for change.7 Within each "kind" was created a rich genetic coding that permitted them to shift their major characteristics to adapt to a wide range of post-Flood environments.8 They say this genetic system would have generated new species rather quickly because the changes occurred through recombination of existing genes in the rich genomes of the "kinds," not mutations as evolution requires.9
According to the young-earth model, this rapid speciation was triggered by environmental pressure working on small, isolated populations. After the Flood, the earth experienced several hundred years of residual catastrophism.10 As the animals left the ark, small groups became geographically isolated. Each group, having a small gene pool, suffered genetic loss as they reproduced–each losing a different portion of their original genetic information. Thus, over time, each group started looking, acting and living differently than original "kind."11
Young-earth creationists insist the Biblical account of history not only accommodates such rapid speciation but requires it.12 However, many creationists consider the fixity of species to be a central pillar of biblical creationism. Given the implications of the young-earth model, it is important to take a critical look at some of the assumptions.Post-Flood Conditions
The young-earth model is predicated on the belief the Flood was a worldwide catastrophe that left the earth ecologically unstable with earthquakes, volcanoes, temperature fluctuations and harmful radiation.13 However, the global-Flood model contradicts a vast body of geological and geophysical data.14 Scientists find no evidence of recent tectonics, volcanism or erosion on a scale nearly as great as the global Flood model requires.15 There are also too many organisms in the fossil record to assert they came from a single generation of living creatures that were killed by the Flood–the earth simply could not support that many organisms.16,17
In fact, if the Flood was as catastrophic as young-earth creationists maintain, it is doubtful anything would have survived. The young-earth model would require vertical land erosion of more than 700 feet per day and tectonic uplift of more than 200 vertical feet per day. Anything more than just one foot of erosion or tectonic uplift is sufficient to destroy most modern cities. Though the ark was seaworthy for a local flood, the G-forces produced by such cataclysmic movements would have destroyed it and its occupants.18
Some species also argue against the global-Flood model. The opossum, for example, shows little change over millions of years. The Cretaceous opossum of 70 million years ago–which most young-earth creationists would classify as pre-Flood because the fossils are found in strata they classify as Flood deposits19–is very much like the opossum of today. Such continuous series of similar fossils tells us no divergence has occurred. This indicates the opossum and other species experienced fairly uniform conditions before and after the Flood.20
Equally important, the Bible does not state the Flood changed the earth. Nowhere does the Bible speak of the volcanism, mountain uplift and continent formation embedded in the young-earth model. Nor is there any indication the post-Flood world was unstable. If that were the case, surely Noah would have expressed concern about the post-Flood conditions and God would have given Noah special instructions on how he was to survive. Instead, the Bible tells us Noah and his family immediately began farming and planted a vineyard–impossible if the conditions were as harsh as young-earth creationists suggest.21Animals on the Ark
The young-earth model assumes Noah took pairs of the originally created "kinds" on the ark–virtually everything but insects and sea creatures.22 However, the Genesis flood account uses two different Hebrew words, nephesh and basar, to describe the animals taken aboard the ark. The word nephesh refers to "soulish" creatures that can relate to humans. The word basar refers to certain birds and mammals that interact with humans.23 Thus, the ark did not contain representatives of all the originally created "kinds." It only contained certain species of birds and mammals that lived within the reach of the Flood’s devastation and were important to Noah’s short-term survival.
The young-earth model also assumes the animals on the ark were unique–they possessed special genetic coding that allowed them to quickly adapt to the post-Flood environment and produce new species. However, nowhere does Bible state the animals on the ark were different or endowed with special qualities. Nor is there a single example from field research that supports this claim. If modern species descended from common ancestors on the ark, we would expect to find evidence of intermediate forms. We would also expect to see thousands of new species arising today. However, nothing we observe suggests today’s species descended from common ancestors on the ark.24
In fact, rapid post-Flood extinctions seem to argue against the position the ark animals were endowed with special qualities. Young-earth creationists maintain God programmed the animals so they could survive and repopulate the earth. Yet, according to their model, a significant number of animals became extinct shortly after the Flood. For example, they contend Noah took dinosaurs on the ark but they were not able to survive the harsh post-Flood conditions and went extinct.25 If God endowed the ark animals with special qualities so they would survive, why did so many species go extinct? And, if only certain animals were endow these special qualities, why did God have Noah take the other animals aboard the ark?