This article is from
Journal of Creation 36(3):17–18, December 2022

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A floating island with growing trees and monkeys observed


Both uniformitarian and creation scientists find it challenging to explain how plants and animals migrated to where they are today other than by land bridges and simple migration.1 Uniformitarian scientists at one time thought, against all odds, that many of these organisms had to have rafted long distances on vegetation mats that were ripped up during storms. Then, when plate tectonics was accepted in the 1960s and 1970s, they thought their biogeographic difficulties were solved. The organisms could simply have ridden the plates to their destinations. However, further analysis has shown that plate tectonics, the vicariance theory,2 would work for only a few organisms. Outstanding examples that necessitate rafting include finding various similar mammals in both Africa and Madagascar and monkeys and rodents that somehow made the trip from Africa to South America.3,5

Uniformitarian challenges to vegetation rafting

However, rafting also brings up numerous challenges. Some researchers say it is ‘impossible’.4 Other than anecdotal tales from four sailors reported in newspapers between 1902 and 1924 collected by Van Duzer,6 there are no observations of mammals on floating islands at sea.

However, there are numerous floating islands in bogs, wetlands, lakes, and rivers. Most of these floating islands are created by mosses that reach out from the banks and then break off. Nonetheless, the example of lizards being swept off one Caribbean island by a hurricane to a nearby island on a vegetation mat7 is a trivial example. The rafting of mammals, with their high metabolic rate and resource requirements (and, for many mammals—large size), appears to be the most difficult problem for biogeography.


Mazza et al. list many variables that all must be satisfied for a successful colonization over water, but they can be grouped into three main considerations: (1) biological variables (table 1), (2) characteristics of the vessel (table 2), and (3) physical variables (table 3).4 Nonetheless, these variables do not exhaust the issues.

To colonize a faraway land, there must be enough interfertile animals on the rafts. Just considering the vessel, it must be able to provide enough food and fresh water, be capable of staying afloat until it reaches the new location, and be carried by the right currents. Natural rafts that have all these characteristics have never been observed. It also has been noted that floating islands descending to the ocean from rivers are quickly broken up by waves.4 If a floating island reached the open ocean, it would not last long. Mazza et al. summarize the many difficulties:

“Nonetheless, given the many complex, intricate and interdependent variables involved in over-sea dispersal of terrestrial mammals, the probability that they could reach remote islands by this means [vegetation rafts] appears vanishingly small.”8

Although admitting to many challenges of vegetation rafting, especially for mammals, Ali and Vences shoot back that such oceanic rafting is still possible and that the alternative of short-lived land bridges suggested by Mazza et al. would have to be miraculous.9 Ali and Vences suggest that for small mammals, large, uprooted trees and vegetation mats could have carried food, and that water might have come from high precipitation in rain belts. Regardless, as improbable as rafting seems to be, it is the only uniformitarian possibility.

Floating islands with trees and monkeys now observed

There are numerous small floating islands on isolated water bodies adjacent to the Magdalena River of northwest Columbia.10,11 The rafts are composed of aquatic plants, bound together and floating. As the floating islands grow, they can support large woody vegetation such as vertical trees. These floating islands typically are 30 m long, but some are greater than 100 m long. One floating island was observed to have trees up to 10 m tall and monkeys on the limbs. Theoretically, as the river floods, it could pick up one of these floating islands and send it down river to the ocean, where it could even float for a distance on the ocean. Apparently, ocean travel has not been observed. Still, the authors believe this observation provides potential for explaining cross-ocean transport.

Photo by the authorfig1-plant-top-piling
Figure 1. A plant growing from the top of a piling along the Columbia River, Portland, Oregon, USA

A more viable creation science explanation

Despite the new observation, the evidence still suggests that the uniformitarian ideas of vegetation rafts and short-lived land bridges are very unlikely. For one, the rafts would be too small, assuming the vegetation was ripped up by a storm, deposited in a river, and carried to the ocean. Then there are the numerous other challenges presented by Mazza et al.4 listed in tables 1–3.

Creation scientists have a much better option for explaining biogeography. First, the rafts of logs and vegetation are a result of a violent global Flood, so they do not have to drift down a river to the sea, but would already be floating on the oceans.1,12 Based on the estimated amount of coal, it is likely that the pre-Flood biosphere had about 10 times the amount of carbon, which could translate into 10 times the number of plants and trees compared to the present earth.13 Although masses of this vegetation were deposited within the sedimentary rocks,14 much of it would have continued to float on the oceans after the Flood. These logs and vegetation mats could be extensive and thick and last many years.15 They should be able to transport small animals, and possibly relatively large animals, across water bodies. The ocean currents and winds during the Ice Age would have been different than they are today. Although we do not know these variables, we are not constrained to explain biogeography by the present-day water currents and wind patterns. Moreover, there was much more rain during the early- to mid-Ice Age,16 so that the need for fresh water on the log mats would not necessarily have been a problem. It is likely plants and even trees grew on these post-Flood floating islands, providing food for animals. I have observed plants growing on wood pilings (figure 1), so the same thing could occur on the floating islands.


The recent observation of ‘floating islands’ large enough to support trees and monkeys provides interesting support for the biblical framework of animal dispersal after Noah’s Flood. Current long-age theories of biogeographical dispersal struggle to explain how rafting across oceans could be viable. However, the Flood would have provided much fodder for the formation of large floating vegetation mats akin to modern ‘floating islands’, but much larger, potentially enabling them to survive trips even across oceans.

Posted on homepage: 16 February 2024

References and notes

  1. Oard, M.J., The Genesis Flood and Floating Log Mats: Solving geological riddles, ebook, Creation Book Publishers, Powder Springs, GA, chapter 8, 2014. Return to text.
  2. Vicariance is: “fragmentation of the environment (as by splitting of a tectonic plate) in contrast to dispersal as a factor in promoting biological evolution by division of large populations into isolated subpopulations”. Vicariance, merriam-webster.com/dictionary/vicariance, accessed 8 Aug 2022. Return to text.
  3. De Queiroz, A., The Monkey’s Voyage: How improbable journeys shaped the history of life, Basic Books, New York, 2014. Return to text.
  4. Mazza, P.P.A., Buccianti, A., and Savorelli, A., Grasping at straws: a re-evaluation of sweepstakes colonization of islands by mammals, Biological Reviews 94:1364–1380, 2019. Return to text.
  5. De Queiroz, A., The resurrection of oceanic dispersal in historical biogeography, Trends in Ecology and Evolution 20(2):68–73, 2005. Return to text.
  6. Van Duzer, C., Floating Islands: A global bibliography, Canto Press, Los Altos Hills, CA, 2004. Return to text.
  7. Calsbeek, R. and Smith, T.B., Ocean currents mediate evolution in island lizards, Nature 426:552–555, 2003. Return to text.
  8. Mazza et al., ref. 4, pp. 1374–1375. Return to text.
  9. Ali, J.R. and Vences, M., Mammals and long-distance over-water colonization: the case for rafting dispersal: the case against phantom causeways, J. Biogeography 46:2632–2636, 2019. Return to text.
  10. Ali, J.R., Fritz, U., and Vargas-Ramírez, M., monkeys on a free-floating island in a Columbian river: further support for over-water colonization, Biogeographia—J. Integrative Biogeography 36(a005):1–8, 2021. Return to text.
  11. Lawton, G., On a raft and a prayer, New Scientists 3365/66:50–52, 18/25 Dec 2021. Return to text.
  12. Oard, M.J., Post-flood log mats potentially can explain biogeography, J. Creation 28(3):19–22, 2014. Return to text.
  13. Archer, D., The Global Carbon Cycle, Princeton University Press, Princeton, NJ, 2010. Return to text.
  14. Oard, M.J., Dinosaur Challenges and Mysteries: How the Genesis Flood makes sense of dinosaur evidence—including tracks, nests, eggs, and scavenged bonebeds, Creation Book Publishers, Powder Springs, GA, 2011. Return to text.
  15. Wise, K.P. and Croxton, M., Rafting: a post-Flood biogeographic dispersal mechanism; in: Ivey, Jr., R.L. (Ed.), Proceedings of the Fifth International Conference on Creationism, technical symposium sessions, Creation Science Fellowship, Pittsburgh, PA, pp. 465–477, 2003. Return to text.
  16. Oard, M.J., Frozen in Time: Woolly mammoths, the Ice Age, and the biblical key to their secrets, Master Books, Green Forest, AR, 2004. Return to text.