Zebras and the truth of Genesis
Posted on homepage: 4 December 2019 (GMT+10)
What’s black and white and testifies to dynamic design in creation?
If you’re thinking zebras, you’d be right.
More than just fashionable horses, these iconic African mammals have captivated—and mystified—humans for millennia. In ancient Rome, the hippotigris (‘horse tiger’) thrilled crowds at circuses.1 In the nineteenth century, humans attempted, not very successfully, to tame zebras for being ridden with saddles and for pulling carriages.2 And to this day, zebras continue to surprise the scientists who study them. Ironically, one of the most puzzling things about zebras is the very feature that makes them so outstanding—those unforgettable stripes.
Herbivorous as well as handsome, zebras spend their days grazing the grasslands and woodlands of southern and eastern Africa. Zebras roam in smaller harems of a male and several females, or in larger herds together with animals like impalas or wildebeests.3 These mixed herds allow many pairs of eyes to stay alert for predators, a task for which zebras are well-equipped given their large, rotatable ears and acute senses of hearing, smell, and vision.
Such features would have been useful for communication and navigation even before animal carnivory entered the world at the Fall. Similarly, hooves well-designed for running now also help zebras escape or resist predators in today’s fallen world.4
In their shape, sounds, and movements, zebras seem uncannily like the horses and donkeys familiar to us. Yet there’s something indelibly wild about these beasts—and it’s not just their sense of style. Where do zebras ‘fit’ in relationship to the tamer equines beneath human saddles? Why do they have those iconic stripes? And what does all this tell us about Genesis?
Meet the ‘horse kind’
If we were to backtrack through history to check out the inhabitants of Noah’s Ark for the pair of zebras that are often depicted as going on board, what would we find?
According to many creation scientists, we would likely not find anything looking exactly like zebras today, but rather a pair of horse-like creatures. At least one of them would likely feature stripes (just like some horses and asses do on parts of their body), though perhaps not as spectacular and body-wide as the stripes on zebras today. You see, zebras belong to the ‘horse kind’, which includes modern horses, donkeys, and other members of the genus Equus, hence sometimes called the ‘equine’ kind. Since it also likely included at least some other genera in the family Equidae, such as the extinct genus Merohippus, an alternative term is the equid kind.
So Noah wouldn’t have needed two of each of these animals on the Ark—two zebras, two donkeys, two Shetland ponies and so on. He would only have needed one male and one female of this kind, which would have incorporated in various degrees the characteristics of those familiar to us today. From these two individuals would have descended, at the least, all the equines known to us, including the many breeds of horses and donkeys on contemporary farms, along with the three zebra species alive today. The genetic potential to create all these descendants already existed in the original duo on the Ark, with different bits of this original genetic information reshuffled or lost via genetic sorting-and-culling processes like natural or artificial selection.5,6
The case of the ‘resurrected’ quagga
A prime example of these processes unfolding in real time is the Quagga Project. The Quagga Project is an initiative to breed zebras to resemble quaggas, a subspecies of plains zebras which went extinct in the 19th century. Unlike ordinary zebras, quaggas mostly bore stripes only on the front part of their bodies, with the rear being light-brown and thus horse-like (see photo top right). Progress toward breeding quagga look-alikes is already well underway, with foals born through the Quagga Project showing fewer and fainter stripes within just a few generations of artificial selection.7 However, offspring apparently cannot (re)gain full striping without a striped individual being introduced back into the population.8 This illustrates both the genetic potential of a few individuals to result in diverse-looking descendants, and that this diversity often reflects a one-way loss of genetic information—in this case, the genes responsible for body stripes. Processes like artificial or natural selection cannot add the sort of genetic information required to turn a running land creature into a marine mammal, as molecules-to-man evolution requires, but they can help explain the variation we see within equines today. Whether striped zebras or part-striped quaggas, these are all still equines.
Zebras—models of within-kind variation
A single created kind like equines can still contain an impressive amount of variation. Instances of this variation exist even among the three different zebra species alive today: plains zebras, Grevy’s zebras and mountain zebras. Differences between these species are evident not only in their subtly different markings, with plains zebras sporting the thickest stripes and Grevy’s zebras the thinnest,9 but also in their different numbers of chromosomes. While mountain zebras have only 32 chromosomes—the fewest of any living equine—plains zebras have 44 and Grevy’s zebras have 46.10 The equine with the greatest number of chromosomes is the rare, endangered species Przewalski’s horse, with 66.10 This variation in chromosome number, however, appears to be mainly due to the rearrangement or fusion of pre-existing chromosomes.10
Your friendly neighbourhood zebroids
Considering this remarkable variation within the genus Equus, how do we know that zebras, horses, and donkeys all belong to the same ‘kind’ created on Day 6 of Creation Week? For one thing, these different equines can interbreed. So many different combinations of hybrid foals have been born, in fact, that some researchers suggest that it is possible for any species of Equus to bear offspring with any other equine species.11 Multiple instances of such hybridizations exist between zebras and other equines, resulting in various types of ‘zebroid’ offspring; zebra-horse (zorse), zebra-pony (zony) or zebra-donkey (zonkey). Besides sporting varying degrees of striping, these ‘zebroid’ hybrids may also betray their mixed heritage through their temperaments, blending the tameness of a domesticated horse with the unpredictability of a wild zebra.8
But hybridization doesn’t only occur among captive equids. For instance, DNA sequence evidence points to significant past interbreeding between wild populations of Grevy’s zebras and Somali wild asses.10 Of course, the chromosomal reshuffling and corruption of genetic information can often leave some Equus hybrids unable to bear offspring themselves. In horse-donkey (mule) hybridizations, for instance, matched chromosomes from the male and female cannot all perfectly align to create fertile offspring. Nevertheless, rare instances of female mules giving birth have been documented.12 Ultimately, the very fact that different equids are able to reproduce despite the genetic events serving to separate them after creation points to their common descent from Noah’s pair of horse-like tenants. They are reproducing after their kind just like Genesis describes.
Why do zebras have stripes?
If all the members of Equus belong to the same kind, why do zebras look so different from other equines? For decades, scientists have pondered this question, speculating about why natural selection might favour zebras’ striped coats. One of the oldest and most commonly-held ideas is that stripes help zebras to camouflage themselves or to confuse predators. While this idea goes back to the 19th century,13 recent research suggests that there’s more to this story. By passing images of zebras through filters that enabled scientists to view zebra stripes the way that predators like lions do, for instance, the researchers realized that predators cannot even see the striped pattern on zebras at long distances.13 Except in wooded areas at close ranges then, stripes apparently do not help break up the zebras’ body outlines or otherwise confuse carnivores.
Other hypotheses for the function of zebra stripes speculate that striping facilitates social interactions, deters disease-carrying parasites, or keeps zebras cool on the hot savannahs. But stripes do not seem to be especially important for social interactions like individual recognition, despite each zebra having a unique striping pattern. For instance, non-striped equines can recognize each other easily.14 However, zebra stripes are reported to vary with the number of biting flies in a region,14 supporting research that stripes attract fewer parasites than solid colours do.15 This may be due to the way stripes polarize light, with thinner stripes being the least attractive to biting flies. Indeed, the range of stripe widths that most disrupts parasites is the range that zebra coats display.16
However, still other research shows that zebra striping relates more to regional differences in environmental temperature than to parasite distribution, suggesting that stripes play a role in thermoregulation.17 One hypothesis is that dark stripes absorb sunlight more strongly than light stripes, so the former become hotter. So air will rise above dark stripes and air from the light stripes will flow in to replace it. The air circulation cools the zebra. Still more recent research, however, suggests that although striped coats are cooler than pure black coats, stripes may not cool zebras any more than a solid grey coat would. For this reason, these researchers favour the hypothesis that zebra stripes help deter parasites.
[Update: After this article was published, new research further supported the parasite-defence function, in particular, biting flies. The stripes don’t repel flies as such, but make it much harder for them to make a controlled landing, which is required for them to be able to suck blood.18—Editors.]
Either way, these studies all assume that zebra stripes have a purpose and function. They agree that knowing this function would automatically explain the stripes’ origin—because they assume microbes-to-man evolution by natural selection to be true (and deliberate design false) in the first place. But design for a particular function is a perfectly scientifically valid explanation for striping—or any other biological feature. Of course, once genetic information for striping exists, natural selection can favour patterns which produce better cooling or disrupt biting fly vision, by eliminating those without such patterns.
And what if these equine stripes—which humans can easily resolve at far distances, even if lions can’t—also serve as functional art, meant for human eyes? That would reflect a Creator who is both adept at designing lifeforms which are functionally efficient and who is inherently creative. And one who is interested in displaying His glory for the eyes of His most special creation—humanity.19
What then, do zebras reveal about Genesis? Their sharp senses and quick hooves are consistent with a once-perfect creation, corrupted by human sin, in which design features like large ears and fast legs may now be co-opted for detecting, fleeing from, or defending against, predators. Their ability to hybridize with other equids points to these animals belonging to the same kind, created on Day 6 of Creation Week. A pair of these survived the Flood and subsequently reproduced after their own kind, as Genesis describes. Finally, zebras’ iconic stripes attest to a Designer who produces very good creations, and who reveals His glory in the process. As far as zebras are concerned then, the truth of Genesis is black and white.
References and notes
- Ridgeway, W., The origin and influence of the thoroughbred horse, Cambridge University Press, 1905. Return to text
- Menzies, J.I., Man and the zebra, Oryx 1(3):127–133, 1951. Return to text
- Schmitt, M.H., Stears, K., Wilmers, C.C., and Shrader, A. M., Determining the relative importance of dilution and detection for zebra foraging in mixed-species herds, Animal Behav. 96:151–158, 2014 | doi:10.1016/j.anbehav.2014.08.012. Return to text
- For more on equine hoof design and response to the idea that horses are ‘icons of evolution’, see Holt, R., What About Horse Toe Evolution?, 25 July 2008. See also Sarfati, J., Horse legs: the special catapult mechanism, Creation 25(4):36, Sep 2003 . Return to text
- See creation.com/selection. Return to text
- Mutations (genetic mistakes) also contribute to the degrading of genetic information. They only very rarely if ever produce any genetic novelty, being inadequate to overcome the overall tendency for gene pools to run down—see creation.com/new-info and creation.com/sanford. Return to text
- Quagga Project News, media1.mweb.co.za/quaggaproject/news.htm, 5 Jul 2007, available via web.archive.org. See also quaggaproject.org. Return to text
- Catchpoole, D., Zebra or horse? A ‘zorse’, of course!, Creation 30(1):56, Dec 2007 . Return to text
- Melin, A. D., Kline, D. W., Hiramatsu, C., and Caro, T. Zebra stripes through the eyes of their predators, zebras, and humans, PloS ONE 11(1):e0145679, 2016. Return to text
- Jónsson, H., et al., Speciation with gene flow in equids despite extensive chromosomal plasticity, PNAS 111( 52):18655–18660, 2014 | doi: 10.1073/pnas.1412627111. Return to text
- Allen, W.R., and Short, R.V., Interspecific and extraspecific pregnancies in equids: anything goes, J. Hered. 88(5):384–392, 1997. Return to text
- Chandley, A.C., Fertile mules, J. Royal Soc. Med. 81(1):2, 1988. Return to text
- Ref. 9. Return to text.
- Caro, T., Izzo, A., Reiner Jr., R.C., Walker, H., and Stankowich, T., The function of zebra stripes, Nat. Commun. 5:3535, 2014. Return to text.
- Gibson, G., Do tsetse flies ‘see’ zebras? A field study of the visual response of tsetse to striped targets, Physiol Entomol 17(2):141–147, 1992. Return to text.
- Egri, Á., et al., Polarotactic tabanids find striped patterns with brightness and/or polarization modulation least attractive: an advantage of zebra stripes, J. Exp. Biol. 215(5):736–745, 2012. Return to text.
- Larison, B., et al., How the zebra got its stripes: a problem with too many solutions, Royal Soc. Open Sci. 2(1):140452, 2015. Return to text.
- Caro, T. and eight others, Benefits of zebra stripes: Behaviour of tabanid flies around zebras and horses, PLoS One, 20 Feb 2019. Return to text.
- Since He designed the information in the original kind, this would be so even if the full glory of a particular feature (e.g. the fullblown striping in today’s zebra) were not apparent in the original population—though it well might have been. Return to text.