• Migration and Recolonization of the Earth Following a Global Flood.


    The Elephants in the Room: Rapid Migration and Recolonization of the Earth Following a Global Flood.

    Mastodons, mammoths, camels, horses, giant bison and giant sloths roaming the mountainsides of the Rocky Mountains may seem like something that only Hollywood could dream up but there is abundant evidence that North America was once home to a thriving community of animals that today we might associate with the African Serengeti.

    Previously (The Snowmastodon Fossil Discovery) we visited a high alpine reservoir dug out of what used to be a high alpine lake. The sediments that had filled in that lake preserved tens of thousands of bones from more than 40 vertebrate animals species. How did this lake form?  How did it fill up with sediment? How did all these bones come to be preserved here? How did the animals preserved here get to Colorado?

    Today we are going to explore the latter question by comparing two radically different interpretations (conventional science vs young-earth creation science) of the history of this location and North America in general. By doing so we will illustrate the monumental task that young earth creationists face as they attempt to interpret this evidence within their highly restricted timeline of Earth’s history. For those not familiar, young-earth creationists (YECs) presume a literal interpretation of Genesis requires that the Earth was created less than 10,000 years ago, that a global catastrophic flood destroyed all breathing land-living animals just 4350 years ago. Though not recorded explicitly in Scripture, they are convinced that the Earth experienced a colder climate but they believe there was only one single Ice Age that reached its maximum extent around 4000 years ago.

    Let’s first consider the prediction from the YEC timeline of Earth history that all of the land animals alive today must trace their ancestry to a single point in the “mountains of Ararat” where Noah’s Ark ran aground.  This raises a number of questions about the distribution, species diversity and population sizes of animals today.

    How did thousands of Ice Age animals get to Snowmass, Colorado?

    Expected (1) YEC response: Each animal preserved at the snowmastodon site is the descendant of a particular pair of animals of their “kind” that departed from Noah’s Ark in the Middle East no more than 4350 years ago. They migrated by walking over land bridges or floating on ocean vegetation mats to North America prior to making their way to the Colorado Rockies where they took up residence around this high alpine lake.

    Camelops was an ancestor of modern Old World camels. It lived widely across western North America and was taller and heavier than modern camels. It is unknown if it had any humps.

    I think it is fair to say that the Snowmastodon site is a mammoth problem for the young-earth advocate.  But it is much more than that, it is an entire ecosystem problem. That is a bit much to tackle, so today we will just focus our attention on elephants and the other megafauna–the large mammals–that are found preserved under this alpine meadow. There are extinct horse species preserved here, remains of an extinct camel related to the camels found in the Middle East and giant bison species probably related to the bison that lives in North America today. There are also remains of a giant sloth (Megalonyx jeffersonii) in addition to coyotes, a bear, deer, and bighorn sheep.

    Each species of animal present at this fossil site represents just one or two species of their “kinds” that YEC claim were preserved on Noah’s ark. Interestingly, most of the animal species (e.g. mammoths, mastodons, giant sloths, giant bison, camel) identified in the lake deposits are extinct today. This observation raises several questions including, why did these animals go extinct if they were adapted to similar climates that exist today and how did so many different kinds of animals migrate all the way to the Colorado Rockies in such a short period of time?  

    Migration and Recolonization of the Earth Following a Global Flood.

    There were many species of ground sloths some of which could stand nearly twice as tall as an adult human. The one in at snowmastodon was only about human height. Image credit: Exhibit in the fossil collection of the American Museum of Natural History, Manhattan, New York City, New York, USA. Wikipedia.

    Consider the case of the members of the giant sloth genus Megalonyx which includes several species which formerly lived throughout North America (see figure below). These larger-than-man sloths should cause any young-earth creationist to ponder the re-population of the  world from a single point only 4350 years ago. The apparent commonness of these animals throughout the entire North American continent contrasts strongly with the complete absence of evidence for their existence outside of the new world (Xenarthrans – another biogeographic puzzle for young earth creationists).   Why should the remains of giant sloths—and all other sloths for that matter—be found only in the New World if they migrated from Noah’s Ark in the Middle East? How did they manage to leave no fossils in the Old World while leaving thousands of fossils in the New World? What was their migratory path to the New World and how could these slow-moving, large animals have made their way into the Colorado Mountains in such a short period of time? Why, if they were so widely distributed and abundant just 4000 years ago or less in the YEC chronology, did they then all disappear? The temporal and geographical distribution of these fossils makes no sense in the restricted timeline of the young-earth paradigm.

    Migration and Recolonization of the Earth Following a Global Flood.

    Distribution of Megalonyx (giant ground sloth) fossils from The Paleobiology Database.

    For me, the most dramatic discovery in this high elevation alpine lake was the evidence that mastodons and mammoths once roamed these mountainsides. In fact, North America was once populated from end to end and top to bottom with elephants (see figure below). Both mastodons and mammoths were a dominant part of the North American ecosystem with mastodons being more common in southern latitudes and mammoths in northern latitudes though there is significant overlap in their natural ranges. Scientists have recovered tens of thousands of elephant bones at hundreds of locations.  If you consider how few bones will be preserved in the geological record it becomes apparent that tens if not hundreds of millions of elephants must have roamed North America at any point in time. This raises a population growth question for YECs, how could populations of elephants have expanded to such enormous sizes in the very short time available in the YEC post-flood chronology?

    Migration and Recolonization of the Earth Following a Global Flood.

    Locations of Proboscidean fossils in North America from The Paleobiology Database. There are over 1300 documented/published collection sites. There may be as many undocumented sites. The snowmastodon site hasn’t even been included yet in this database!

    This re-population problem has not escaped the notice of YECs who have generally swept aside such questions by appealing to simple idealized exponential population growth models for animals reproduction.  For example, Nathaniel Jeanson from Answers in Genesis, has responded to the problem of population sizes including that of the long-lived elephants. Using an ideal population growth model that includes maximum observed reproduction for each female elephant and no deaths before senescence (i.e. no predation or illness) he projects that by 100 years after the Flood if the two elephants that got off the ark experienced ideal population growth conditions there could have been 750 elephants on the whole face of the Earth and by 200 years, 300,000 individuals. Continued exponential growth results in hundreds of millions of elephants by 400 years and by 1000 years after the Flood more elephants could have been alive than the environment could support.  Hence, it is theoretically possible that billions of elephants could have lived on Earth in the 4350 years of the YEC compressed chronology.

    But theoretical possibilities often tell us little of practical realities. For example, is it realistic to assume that elephants did not experience any or even very little predation? After all we have evidence from the fossil record that humans killed elephants and certainly lions and tigers and hyenas will opportunistically kills elephants as well.  Furthermore, in the YEC accounting of the post-Flood world it was still a chaotic place, experiencing large volcanic eruptions, floods and massive climate change. There are many fossils of many juvenile elephant fossils attesting to the fact that not all elephants would have achieved reproductive age much less has the maximum offspring necessary to continue exponential growth.

    The factors above would greatly reduce overall population growth but that is just the beginning of the population and migration challenge to YEC chronology. It isn’t just about showing how large numbers can be attained, a realistic model must also account for the particular distribution of those elephants, their existence as many species and when they lived and went extinct. When these factors are examined we begin to see some very consequential problems with the YEC timeline.

    Consider first that there are over 100 identified fossil species of elephants. YECs have suggested that all the species of the “elephant family” were derived from a common ancestor on the ark. If this is true then each of those species must have “evolved” from the common ancestral pair on Noah’s Ark.  Therefore the total number of all elephants that has lived on Earth must include every individual from each species, extant and extinct, of all the pachyderms commonly referred to as elephants.

    Most elephant species are known only as fossils. From their locations in the fossil record we would infer that they would have gone extinct not long after their origins after the Flood under a YEC paradigm.  From  fossils we further observe that dozens of elephant species have existed on every continent and in abundant numbers–some species are known from hundreds of locations found continent-wide–well before man migrated into most of the world. In the severely compressed YEC chronology of Earth’s history, elephants appear to exist in great numbers nearly immediately after Flood.  Oddly, the species that are common today also have a fossil record but one that does not go nearly as deep as other elephant species.  It is as if dozens of species of elephants populated the entire world before the modern species of elephants appeared on Earth and are the only survivors of a once much larger group.

    The YEC model must predict why many species only persisted for a few hundred years but for us to be aware of them through their fossils we would expect that they should have had very large population sizes since fossilization is very rare (this is especially true for the YEC who thinks that fossilization requires very rare conditions outside of a global flood, and these elephants must have lived and died after Noah’s Flood). Furthermore, the rapid speciation necessitated by this model–dozens of species forming within just a few generations of elephant reproduction–is also untenable but we won’t discuss that at this time.

    The presence of multiple species of elephants living contemporaneously at the same locations raises some additional questions for the YEC biologist. How is it that mammoths and mastodons which are supposedly related by common ancestor on Noah’s Ark live with each other and yet retain their species distinctiveness? There were millions and millions of each species living in North America, many in the same locations, yet  members of each species are so uniform in appearance that  a child could easily distinguish  a mastodon versus a mammoth while at the same time have difficulty finding a significant difference between two mammoths. How did these species become so different from one another but then not change significantly as they grew into populations of millions of animals (2)? Put another way, YECs say that a hallmark of being in the same “kind”–a monophyletic group of an ancestor and all of its descendant species–is the ability to interbreed. How could so many mastodons and mammoths have lived in the same place and yet never interbred with one another if they are the same “kind” and thus had the same ancestral parents?

    Above we saw that idealistic population growth models can theoretically account for populations of billions of elephants within a 1000 years but let us trace the YEC timeline for elephants. Two elephants get off the ark. After 100 years a maximum of 750 individuals is projected using Nathaniel Jeanson’s maximum model of population growth. These 750 elephants must have diversified into at least 10 species by this time and therefore each species was represented by an average of only 75 individuals.  Entire species groups must have set out on massive migrations leading away from the Middle East.  It is unclear to me why most of these species, or any other animal for that matter, felt compelled to travel 10,000 miles when the region they came from was very sparsely populated and therefore probably much more suited for life than the areas they would have to travel through (imagine you are giant sloth making your way across the Beringia land bridge between North America and Asia) to get to new habitats.

    Migration and Recolonization of the Earth Following a Global Flood.

    A single family group of mammoths had to have wandered to North America during the Ice Age which created a land bridge between Asia and North America. This would have been around 4200 years ago in the AiG chronology. At the same time a family group of mastodons had to make the same trek but remain reproductively isolated from the mammoths. Once in North America they had to rapidly reproduce and divide into thousands of families—but not change into new species as their ancestors had done just a few hundred years before—that then cover the continent from Alaska to Florida.

    But the mastodons, mammoths, giant sloths and other large animals of Snowmass Colorado had an even more arduous trip ahead of them. They pushed on through the deserts of Wyoming, Utah and western Colorado, made their way up the gorges of the Colorado River then up the mountain valley to Snowmass where they then made it to the top of this alpine ridge. If you have traveled along the Colorado River and up to Aspen you will know that this is no easy trip. To top it off they not only had to take up residence here at least part of the year but they had to die at the edge of the lake and not on the side of the ridge or in the valley below during the winter where they presumably would have migrated for some of the year. Either every animal that made it to the lake happened to also die in the lake itself or there was an enormous population in the area and only a small percentage ended up in that lake.

    Within the context of standard chronology, mammoths and mastodons both lived in North America for at least a million years. Therefore, finding both species and other megafauna in nearly every nook and cranny of the continent should be no shock. But if a family of mastodons arrived in North America just 4000 years ago, is it reasonable to expect to find their remains in nearly every corner of the continent and in so many different habitats especially given that almost as soon as they arrived they also went extinct?

    Let’s not forget that in the YEC-hypothesized chronology, humans arrive in North America almost synchronously with mastodons and mammoths and sloths(3).  It seems unlikely that these animals could rapidly reproduce and cover the continent if people were there to consume them. We know from multiple lines of evidence that people did kill mammoths. Sloths were also easy prey when they encountered humans and yet they populated the entire continent as well.  If man is partially or fully responsible for the demise of the North America megafauna, does the YEC chronology which maintains that man entered North America almost synchronously with the megafauna make any sense (4)? Why should we believe that humans had no effect on the growth of megafauna populations, and yet, once the populations grew to millions, the humans eradicated them?  This makes no sense at all. Humans reproduce and thus incur faster population growth than any of the megafauna.   Rather than seeing the megafauna spread over the entire continent and then suddenly decline we might expect that the megafauna would have great difficulty in establishing themselves in light of the competition with humans. Within the context of standard geological chronology humans entered into North America hundreds of thousands of years after the megafauna were already well established in the continent thus finding evidence that millions of elephants lived in North America is not a surprise.

    For YECs, the post-flood migration problem is serious. They have hand-wavy explanations for some animal migrations (e.g. rafting on vegetation mats across the ocean). These explanations are usually ad hoc hypotheses proposed to solve a specific animal migration problem.  However, the migration and population growth challenge is increased exponentially when one considers that it isn’t just one type of animal that had to get to this remote location in the Colorado mountains against all odds but hundreds of species, each of which have their own migratory challenges.

    The megafauna are just the beginning of the problem.  Do we really need to go on and discuss the likelihood of snakes slithering from the Ark all the way to North America and then up to this mountain lake in just a few hundred years!?


    1 Each of the YEC responses I provide are in some sense hypothetical because they are not direct quotes or responses to the specific question.   The “expected” YEC response refers to the what we would expect a YEC to say if they are consistent with the majority of their own literature on the subject.

    2 This raises the question of how YECs view speciation. They believe that tens or even hundreds of species can be derived from a single ancestral pair of animals but if mammoths, mastodons, African and Asian elephants all speciated from a common ancestor very recently we could ask, where are the intermediate animals or where are the transitional fossils.  YECs often accuse evolutionary biologists of not providing transition fossils as evidence of the connections between species but don’t YECs then face the same problem, assuming it is one?

    3 Here is one example from John Morris (President of the Institute for Creation Research) who in 2009 characterized the history and biodiversity of elephants this way: “I think we can reasonably say that the “elephant kind,” in obedience to God’s command given in Genesis 8:17, were filling the recently devastated earth adapting to various areas as they went. They flourished initially, but some varieties were eventually overwhelmed in major storms during the Ice Age, others hunted to extinction by humans, while still others survived to the present day.” (Morris 2009) Furthermore, Oard argues that the Ice Age killed off most of the megafauna because it makes no sense that animals dies while the climate was warming and conditions were improving. But this site in Colorado clearly contradicts his chronology since the megafauna were at this lake long after evidence of an Ice Age.

    4 Notice on this chart about the Ice Age the AiG produced that they refer to man migrating to North America by a land bridge and eating mammoths along the way. So they see the migration is nearly synchronous and they believe that humans would have hunted mammoths which would have greatly impacted the mammoths ability to population North America.



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