This article is from
Creation 33(3):28–31, July 2011

Browse our latest digital issue Subscribe

Turtles at loggerheads with evolution


Gary Bell, oceanwideimages.comLoggerhead turtle

Loggerhead turtles, thus termed because of their massive heads with large crushing jaws,1 certainly get around. Just as the aptly-named ‘Crush’ in the animated movie Finding Nemo famously rode “the EAC” (East Australian Current), so real loggerheads migrate not just from north to south along the east coast of Australia2 but also across the wide expanses of the Pacific and Atlantic oceans. For example, the journey that loggerhead turtles take from their nesting beaches in Japan to their feeding areas along the Californian coast and back is the longest migration known for a marine animal.3 The enormous range of loggerhead turtles encompasses all but the most frigid waters of the world’s oceans. How are loggerheads able to navigate across thousands of kilometres of open ocean, all the way back to the very beach where they hatched, to lay their eggs?

For over a decade now, it has been known that loggerheads, even as hatchlings, can use the earth’s magnetic field to help them tell north from south and steer themselves along the right latitude.4 How could such an amazing ability have arisen by evolution? As famous evolutionist J.B.S. Haldane noted in 1949, evolution could never produce “various mechanisms such as the wheel and magnet, which would be useless till fairly perfect”.5 To detect the earth’s magnetic field, loggerhead turtles must have some sort of magnetic sensor—thus, by Haldane’s criterion, proving evolution false.6

Despite this, modern evolutionists have blithely continued to credit the loggerhead’s navigational capabilities to evolution, illogically disregarding the sophisticated design required for magnetic field sensing. And now recent findings have caught evolutionists by surprise, as it has been discovered that loggerheads’ positional and directional sense is way better than expected—explaining it without a Creator just got a whole lot harder.

Loggerhead longitude long-shot

wikipedia.orgNewly hatched loggerheads
Newly hatched loggerheads are only about 5 cm (2 inches) long. They spend the first 7 to 12 years of their lives far out at sea, eventually returning to reproduce in the same area where they hatched.

Notwithstanding loggerhead turtles’ ability to use magnetic cues to determine latitude, it was widely believed that this wasn’t possible for longitude, because of how little the earth’s magnetic field varies in the east-west direction around the globe. (When you travel north or south away from the earth’s magnetic poles, their pull weakens substantially. In contrast, when travelling straight east or west, the intensity of the magnetic pull essentially doesn’t change—only the angle of the magnetic pull changes, and that only to a very slight degree.) As Princeton University evolutionary biologist James L. Gould put it in 2008, regarding turtles and other migratory animals’ uncanny ability to steer an accurate course: “A skeptic could reasonably believe that the latitudinal cue is magnetic, but that determining east-west position depends on magic.”7

However, loggerheads have surprised evolutionists by demonstrating, “against reasonable expectation”,7 that the turtles can clearly determine longitude.8,9 The researchers took turtles that had just hatched in Florida but had never been in the sea and put them in a pool surrounded by computer-controlled magnetic coil systems. The magnetic coils were set to reproduce the geomagnetic characteristics of two points on the loggerheads’ trans-Atlantic migratory route at identical latitude—one in the western Atlantic, near Puerto Rico, and the other in the east, near the Cape Verde islands. Turtles in the ‘Puerto Rico’ tank swam northeast, just as loggerheads in the wild do when setting off on their migration, riding the currents that circle the Sargasso Sea and loop around the Atlantic. In the ‘Cape Verde’ pool however, the loggerhead hatchlings headed northwest, as if returning on the homeward leg of their circular migratory route.

wikipedia.orgAdult female
Adult female loggerheads lay eggs in clutches of 100 to 150 eggs, burying them in dry sand. They do not hatch until about 60 days after being laid (during which time they might fall prey to wild pigs, raccoons, foxes or people—the eggs are very nutritious). After hatching underground, hatchlings dig their way up through the sand, waiting just beneath the surface until cooler temperatures signify nightfall. Then they pop out and scurry towards the ocean in a race against birds and other predators.

So, loggerheads can detect both the intensity (field strength) and the inclination (angle) of the earth’s magnetic field to create “a mental map that covers all four points of the compass”.10 Actually, it’s more like a GPS11 than a mere direction-finding compass. As University of North Carolina researcher Nathan Putman pointed out, “a compass doesn’t really tell you where you are” whereas loggerheads’ mental magnetic map “gives them positional information”.12 I.e., “turtles determine longitudinal position by using pairings of intensity and inclination angle as an X, Y coordinate system.”

Putman adds that the findings might have a role to play in the development of human navigational technologies. “There may be situations where satellite might not be available, where this system of using two aspects of a magnetic field could be very useful,” he said.13

In one sense, one can appreciate evolutionists’ surprise at the loggerheads’ “astounding migrational abilities”10 in relation to longitude. After all, it took human navigators hundreds of years to figure out how to determine longitude in their long-distance voyages—even with the impetus of huge prizes offered by Spain, France and then Britain.14 (Eventually, John Harrison (1693–1776) with his chronometers won the most money—£23,065, equivalent to over £3.3 million today.)

Thus the ability to determine longitude, requiring such intense and directed human intelligence, would surely not be found in the “tiny brains”10 of loggerhead turtles—for surely such could not have arisen through evolutionary processes?

Indeed not—and therefore the fact that turtles have that capability points to its having originated from an intelligence surpassing that of humans, i.e. loggerheads have such features by design, not by evolution. In light of Romans 1:20 (those who deny the Creator are “without excuse”), one can see there’s a reason that turtles are at loggerheads with evolution. They were created to thwart evolutionary storytelling!

And it’s not just in relation to their design. There’s no joy for evolutionists in the fossil record, either.

Gary Bell, oceanwideimages.comcarapace
The shell on the back of the turtle is called the carapace, while the shell on the belly side is called the plastron. Loggerheads are the largest of all hard-shelled turtles (cf. leatherbacks which are bigger but have soft shells), with adult males generally reaching about 90 cm (3 ft) in shell length and weighing about 110 kg (250 lb). However, some reports say that larger specimens over 450 kg (1,000 lb) have been found!

Turtle fossils ‘all the way down’

As if there weren’t already enough paleontological and other challenges posed by turtles to evolutionary theory,15 the past decade has made it even more difficult to fit these singular creatures into an evolutionary ‘tree’. Many and varied have been the century-long attempts to explain the origin and phylogenetic relationships (which presume a common ancestry of all living things) of turtles. Traditional ideas have been up-ended by more recent morphological and molecular studies.16 But there is still no consensus—on the basis of comparisons of body form (morphology), evolutionists have variously claimed tuataras, lizards and snakes as turtles’ closest relatives, but molecular comparisons draw other evolutionists to favour crocodiles and birds as the “living sister group” of turtles.16

Gary Bell, oceanwideimages.comjaws
Loggerhead turtles can use their powerful jaws to crush prey like conches, crabs and other animals with hard shells. But they also eat softer foods such as jellyfish, seaweed and a brown alga called sargassum.

The recent discovery of a turtle fossil in Upper Triassic strata in China, presumed by evolutionists to be 220 million years old,17 has re-ignited another debate. Dubbed Odontochelys semitestacea, two reviewers (Tyler Lyson and Scott Gilbert) say the fossil “reopens the debate regarding the origin of the turtle shell”.18 This is the debate as to how the turtle’s carapace might have arisen in an evolutionary stepwise process from other parts of the turtle body over long periods of time. But, as evolutionists have admitted, “the turtle body plan is quite unique among vertebrates and is difficult to derive from a generalized pattern of the amniotes.”19 (Amniotes = reptiles, birds, mammals.) And in the absence of definitive transitional fossils, such evolutionary speculation is exactly that—speculation!20 Stasis is a feature of the turtle fossil record—turtles have always been turtles.21 The title of the paper by Lyson and Gilbert summed up the evolutionary conflict perfectly, Turtles all the way down: loggerheads at the root of the chelonian tree. This sentence from their closing paragraph is just as candid:

“The new discovery of the beautifully preserved fossil O. semitestacea produces more questions than it answers, reopening questions of turtle origins, shell evolution, and original paleoecology.”18

You can find a correct answer, based on true history, to the question of the origin of turtles, and the timing of the fossilization of the O. semitestacea turtle fossil, in the Bible. Turtles were created on Day 5 of Creation Week (see box) only about 6,000 years ago, and this fossil dates from the Flood of Noah’s day, about 4,500 years ago—a hugely violent, worldwide event. That’s why this and so many other fossils are, like it, “beautifully preserved”.18 But this explanation only works for those who don’t want to “deliberately forget”—2 Peter 3:5–6.

Loggerheads are no landlubbers

Loggerhead turtles (Caretta caretta) live in oceans all over the world, except in the most frigid waters. Having paddle-like flippers for swimming, and streamlined carapaces, loggerheads are renowned for their long-distance oceanic migrations (up to 4,800 km or 3,000 miles),1 and pin-point accurate navigation. (Adult females often exhibit natal beach nesting, i.e. laying their eggs on the very same beach where they themselves hatched.)

Despite their evident aquatic prowess, evolutionists say these sea turtles are “limited by their land-dwelling ancestry”, as they must breathe air and nest on dry land.2

But a creationist perspective makes much more sense. Their need to breathe air is no impediment to them at all, being able to dive for up to 20 minutes, and even rest for hours without breathing. (In any case, loggerheads’ food is mostly found in the relatively shallow coastal waters, where their average dive is only three to four minutes.) Their ‘attachment’ to land during their lifetimes is minimal: no more than two months as eggs buried in sand, a few hours at most as hatchlings journeying from nest to sea, and a few hours again for adult females when making landfall to lay eggs. So loggerheads are best viewed as sea creatures, created on Day 5 of Creation Week.

But some might ask, how could sea turtles have survived the global Flood of Noah’s day, with no dry land available for nesting, if they were not taken aboard the Ark? The answer lies in the fact that females only nest every two to five years. So, once the Flood waters went down, the surviving sea turtles could begin reproducing again. Female loggerheads lay up to five clutches of eggs in one nesting season, with up to 150 eggs per clutch—that’s a lot of turtles! Thus loggerhead populations could rapidly recover from Flood losses and from any interruptive effect of the Flood on reproductive cycles. Loggerheads attain mature size between 10 and 30 years of age, and reproductive life span after reaching maturity is estimated at about 32 years. So, it’s no problem for loggerheads to survive the Flood.

  1. University of Michigan Museum of Zoology, Caretta caretta—loggerhead sea turtle, animaldiversity.ummz.umich.edu/site/accounts/information/Caretta_caretta.html, acc. 14 March 2011.
  2. Lohmann, C. and Lohmann, K., Sea turtles, Current Biology 16(18):R784–R786, 2006.
Posted on homepage: 1 October 2012

References and notes

  1. Chapter 10, “Loggerheads: A Crushing Jaw” in Spotila, J., Sea Turtles: A complete guide to their biology, behavior and conservation, The John Hopkins Community Press, Baltimore, Maryland, USA, 2004. Return to text.
  2. Turtle’s Finding Nemo journey, The Daily Telegraph, www.dailytelegraph.com.au/news/nsw-act/turtles-finding-nemo-journey/story-e6freuzi-1111116173039, 27 April 2008. Return to text.
  3. Lohmann, C. and Lohmann, K., Sea turtles, Current Biology 16(18):R784–R786, 2006. Return to text.
  4. Sarfati, J., Turtles—reading magnetic maps, Creation 21(2):30, 1999; creation.com/turtlemap. Return to text.
  5. Is Evolution a Myth? A Debate between D. Dewar and L.M. Davies vs. J.B.S. Haldane, Watts & Co. Ltd / Paternoster Press, London, 1949, p. 90. Return to text.
  6. And loggerheads, in company with all multicellular creatures, have an enzyme called ATP synthase, which is actually a rotary motor—a type of ‘wheel’ (see Creation 31(4):21–23, 2009; creation.com/atp-synthase), thus fulfilling Haldane’s other criterion. Return to text.
  7. Keim, B., Navigational ‘magic’ of sea turtles explained, Wired Science, wired.com/wiredscience/2011/02/turtle-navigation/, 24 February 2011. Return to text.
  8. Pearson, A., Loggerhead turtles have a magnetic sense for longitude, New Scientist, www.newscientist.com, 25 February 2011. Return to text.
  9. Putman, N., Endres, C., Lohmann, C., and Lohmann, K., Longitude perception and bicoordinate magnetic maps in sea turtles, Current Biology 21(4), doi:10.1016/j.cub.2011.01.057, March 2011. Return to text.
  10. Macrae, F., No need to shell out for a satnav: Loggerhead turtles use Earth’s magnetic field to make a mental map of their migration, www.dailymail.co.uk, 24 February 2011. Return to text.
  11. Global Positioning System; see also interview with satellite specialist Dr Mark Harwood, Creation 26(4):18–23, 2004; creation.com/what-goes-up. Return to text.
  12. Palca, J., For turtles, Earth’s magnetism is a built-in GPS, NPR News, wap.npr.org/news/front/134175104, 2 March 2011. Return to text.
  13. Sea turtles’ migration mystery is ‘solved’, BBC News, www.bbc.co.uk, 25 February 2011. Return to text.
  14. Gould, J., Animal navigation: The longitude problem, Current Biology 18(5): R214–R216, 2008. Return to text.
  15. Weston, P., Turtles, Creation 21(2):28–31, 1999; creation.com/turtles. Return to text.
  16. Zardoya, R. and Meyer, A., The evolutionary position of turtles revised, Naturwissenschaften 88:193–200, 2001. Return to text.
  17. Li, C. and 4 others, An ancestral turtle from the Late Triassic of southwestern China, Nature 456:497–501, 2008. Return to text.
  18. Lyson, T. and Gilbert, S., Turtles all the way down: loggerheads at the root of the chelonian tree, Evolution & Development 11(2):133–135, 2009. Return to text.
  19. Kuratani, S., Kuraku, S. and Nagashima, H., Evolutionary developmental perspective for the origin of turtles: the folding theory for the shell based on the developmental nature of the carapacial ridge, Evolution & Development 13(1):1–14, 2011. Return to text.
  20. The Odontochelys semitestacea fossil and the evolutionary controversy arising are discussed in detail in Sarfati, J., The Greatest Hoax on Earth—Refuting Dawkins on evolution, Creation Book Publishers, Atlanta, USA, pp. 141–143. (Available via creation.com/store.) Return to text.
  21. ‘Living fossil’ turtle evidence—no evolution, Ref. 15, p. 29; Bell, P., Evolutionary Stasis: Double–Speak and Propaganda, Creation 28 (2):38–40, 2006; creation.com/evolutionary-stasis. Return to text.

Helpful Resources