Share
A- A A+

Article from:

Creation  Volume 26Issue 4 Cover

Creation 26(4):28–33
September 2004

Free Email News
By Design
by Dr Jonathan Sarfati

US $15.00
View Item
God the Master Designer DVD
by Dr Jonathan Sarfati

US $13.00
View Item
The Creation Answers Book
by Various

US $14.00
View Item
Creation  Volume 26 Issue 4 Cover

First published:
Creation
26(4):28–33
September 2004

Browse this issue

Subscribe to Creation magazine

A coat of many colours

Captivating chameleons

by

The chameleon (the name of which means ‘ground lion’ in Greek) is a lizard with many remarkable features. About 90 species have been identified,1 and 59 of them live in Madagascar.2 However, there are only two genera,1 which probably means that there were originally only one or two created kinds, which now have many varieties.3

They live mostly in trees and eat mainly insects, although large chameleons can eat birds. Most chameleons grow to 17–25 cm (7–10 inches) long, while the longest can reach 60 cm (2 ft).4 Chameleons are sometimes insulted as ‘the most primitive group of lizards’,5 but they have many unique design features.

Colour change

Panther chameleon

Chameleons are famous for being able to change their colour. However, ‘It is a popular misconception that the chameleon changes its colour to match that of the background.’1 Rather, they have a basic pattern that provides camouflage, and the colour changes are due to heat, light, and can also reflect their mood! For example, if a panther chameleon gets angry, then red and yellow replace its normal colour.6 Perhaps other chameleons recognize this as a warning to keep away? Many believe that the chameleon’s colour helps to communicate its mood to other chameleons—‘wearing its heart on its sleeve’, so to speak. One type of male chameleon, when he wants to attract a female, will change from brown to purple and light blue, with his eyelids turning yellow with green spots.

How do they do it? They change colour with their highly structured skin. Underneath a transparent outer layer, there are two layers of red and yellow pigments, contained in cells called chromatophores. Below that are two more layers, one reflecting blue and another reflecting white. Deeper still is a layer of the dark brown pigment melanin contained in cells called melanophores.7 These are the most important for colour change, because they have ‘tentacles’ reaching into the upper layers.

The colour changes when the cells expand or contract. E.g. a calm chameleon might look green when its yellow chromatophores are partly contracted, letting reflected blue light through as well. An angry chameleon may be yellow because the yellow cells are large enough to block the blue light from shining through.2 Yellow can also result when the blue layer is missing, allowing the white light from the next layer to shine through and brighten the other colours.

Magnification of the chameleon’s skin

The chameleon’s highly structured skin seen magnified. The outer layer of skin is made of keratin, like the material in our skin and fingernails. Their skin does not expand as the animal grows, and requires shedding periodically. An adult sheds about every four months, while a baby approximately every few weeks. A chameleon’s skin usually looks green. However reactions to heat and cold, stress, shock and other stimuli may result in the skin appearing black, and may even create stripes and spots.

The skin lightens when the melanophores pull melanin inwards. But when a chameleon is enraged, the melanin spreads into the outer layers and the skin may blacken.

Telephoto lizards8

Chameleons have large eyes that can move independently. They also use a unique ‘telephoto principle’ to measure distances. Consider an old-style camera where you turn a dial to bring an object into focus—you could tell how far away the object is by reading the distance setting of the dial when the object is focused.9

For the chameleon to focus accurately, the lens must form a large image on the retina. The chameleon’s eye produces the largest image of any vertebrate compared to its size. This is formed by an ‘astonishing’9 negative lens,10 likely ‘unique among animals’,9 i.e. it makes light diverge rather than converge.

The chameleon can see a sharp image of an object from almost any distance away. That is, its eye can accommodate very well, so it can even clearly see an object just 3 cm (just over an inch) away. In contrast, in human vision, objects become blurry if they are closer than twice that distance. We really need objects to be 30 cm (1 ft) away before we can see them as clearly as a chameleon can.

Terrific tongue

The chameleon needs this fine judgment of distance to capture prey with its tongue. This is another remarkable feature—the tongue can reach up to 1 ½ times the lizard’s body length. The acceleration of this ‘ballistic tongue’ is amazing—50 g (i.e. 50 times the acceleration due to gravity), while astronauts and jet fighter pilots will pass out at only 10 g. The chameleon uses special supercontracting muscle, ‘unique among vertebrates’ and otherwise found only in invertebrates.11 This is necessary to produce the tension over the great changes in muscle length.

A special high-speed X-ray camera is required for scientists to film the tongue through its entire movement (including inside the mouth).12

Suction cap

Most lizards catch insects on their tongue just by the stickiness of the moist surface. But the chameleon’s fast tongue also manages to capture large, smooth prey. It does this with yet another mechanism. Just before the tongue hits the prey, two muscles pull the central part of the tip backwards, forming a suction cap.5

Catapult

How does the tongue accelerate so much? Even supercontractile muscle can’t explain that totally—it would need to generate 10 times as much power as it does. Some animals generate high accelerations by using their legs as levers, but even a kangaroo rat13 can reach only 19 g while jumping.14

Close analysis reveals that the tongue has an ingenious catapult system.15 A catapult is a machine with a stiff frame, allowing a large force to store energy in an elastic material, then releasing it suddenly to accelerate a small mass. An article in the journal Science said, ‘The chameleon’s “sliding spring” is remarkably compact, efficient and easy to control.’14 The lead researcher, Dr Johan van Leeuwen, of Wageningen University in the Netherlands, said, ‘So far we have not seen a parallel structure in biology or mechanics—it is a completely novel design.’16

National Geographic said, ‘The collagen catapult is beginning to receive attention from engineers who believe it may have a variety of medical applications.’16

Created, not evolved

One of the papers5 on the tongue’s design had a curious section, ‘Evolutionary considerations’. The author admitted that the suction cap and the ballistic tongue are both essential to capture prey, i.e. one is useless without the other. Yet he interpreted this as evidence that they must have ‘evolved simultaneously … early in their evolutionary history.’ A far better interpretation is that chameleons have always been chameleons, and were designed with both these mechanisms fully functional.

There is a good lesson here. Practical biological research assumes that features of living things have a function, so it makes sense to find out how they work. This makes perfect sense if these features have been designed for a purpose. So all the useful research was carried out as if the researchers were creationists for all practical purposes. But then evolutionists try to make up just-so stories to explain how these features evolved. Yet this extra ‘Evolutionary considerations’ section added nothing whatever of practical value.17

So how does the chameleon’s insect-eating fit with the biblical teaching of death as the result of the Fall of Adam? First, insects are probably not ‘living’ in the sense of being ‘soulish’, as vertebrates are—the Bible never calls them nephesh chayyah (Hebrew נֶפֶשׁ חַיָּה = living souls/creatures). Second, this could have been a latent feature programmed into the genes by the Creator who foreknew the Fall.18

Chameleon catapult

  • The chameleon tongue has a bone, which provides the stiff frame. Surrounding the bone are at least 10 slippery sheaths. These contain coiled collagen fibres, which are the elastic material. The sheaths, in turn, are surrounded by the powerful accelerator muscles, providing the stretching energy.
  • When the chameleon wants to flick out its tongue, it activates these muscles. Now muscle is incompressible, i.e. its volume remains the same. (For example, when you flex your biceps, the muscle contracts, and to keep the volume constant, it bulges outward.) In the chameleon tongue, the muscles squeeze inward, and to keep the volume constant they lengthen along the tongue. This stretches the sheaths like elastic bands.
  • When the sheaths come to the rounded tip of the tongue bone, they slide forward and off. With the bone out of the way, the sheaths can relax inward and contract in length quickly. This forces the tongue off the bone, and the ‘sliding spring’ mechanism releases the stored energy to shoot the tongue forward at dazzling speed. Then the concentric sheaths extend like tubes of a telescope.1
Chameleon

The tongue projector is more efficient than a man-made catapult—the latter loads and releases the energy along the same path, while the chameleon tongue releases the energy in a different path. This means that the tongue needs no extra moving parts to release the tension suddenly, because the energy is released as the tongue slips forward and off the bone. Also, while the acceleration is certainly sudden, the energy is still released steadily as the sheaths slide off in turn, rather than all at once. Otherwise a lot of the energy would be wasted in deforming the tongue, and be lost in vibrations.2

References

  1. Schilthuizen, M., Slip of the chameleon’s tongue, Science Now, <sciencenow.sciencemag.org/cgi/content/full/2004/308/1>, 8 March 2004.
  2. Müller, U.K. and Kranenbarg, S., Power at the tip of the tongue, Science 304(5668):217–219, 9 April 2004.

Related Articles

Further Reading

References and notes

  1. Article ‘chameleon’, Encyclopædia Britannica 3:69, 15th ed., 1992.
  2. Raxworthy, C.J., A Truly Bizarre Lizard, The Living Edens, 20 April 2004.
  3. For explanation of biblical kinds, see Sarfati, J., Refuting Compromise, chapter 7, Master Books, Arkansas, USA, 2004.
  4. They also have a unique ‘zygodactylous’ toe pattern, i.e. opposed bundles of two and three fused digits. Their teeth are attached to the jaw edge (called ‘acrodont dentition’).
  5. Herrel, A., Meyers, J.J., Aerts, P. and Nishikawa, K.C., The mechanics of prey prehension in chameleons, Journal of Experimental Biology 203:3255–3263, 2000.
  6. National Geographic Explorer—Chameleons, <magma.nationalgeographic.com/ngexplorer/0210/articles/mainarticle.html>, 21 April 2004.
  7. Holladay, A., How do chameleons change color and how do they know what color to change to?, Wonderquest, <www.wonderquest.com/Chameleons.htm>, 14 March 2001.
  8. Telephoto lizard, Focus, Creation 19(1):7, 1996.
  9. Land, M., Fast-focus telephoto eye, Nature 373(6516):658–659, 23 February 1995; comment on ref. 10.
  10. Ott, M. and Schaeffel, F., A negatively powered lens in the chameleon, Nature 373(6516):692–694, 23 February 1995.
  11. Herrel, A., Meyers, J.J., Timmermans, J.P. and Nishikawa, K.C., Supercontracting muscle: producing tension over extreme muscle lengths, Journal of Experimental Biology 205:2167–2173, 2002.
  12. Snelderwaard, P.Ch., de Groot, J.H. and Deban, S.M., Digital video combined with conventional radiography creates an excellent high-speed X-ray video system, Journal of Biomechanics 35:1007–1009, 2002.
  13. Weston, P., Kangaroo rats, Creation 26(3):18–20, 2004.
  14. Müller, U.K. and Kranenbarg, S., Power at the tip of the tongue, Science 304(5668):217–219, 9 April 2004.
  15. de Groot, J.H. and van Leeuwen, J.L., Evidence for an elastic projection mechanism in the chameleon tongue, Proceedings of the Royal Society London B, 271(1540):761–770, 7 April 2004.
  16. Trivedi, B.P., ‘Catapults’ give chameleon tongues superspeed, study says, 19 May 2004.
  17. See also Wieland, C., Evolution and practical science, Creation 20(4):4, 1998.
  18. See also Batten, D. (Ed.), Ham, K., Sarfati, J. and Wieland, C., The Answers Book [now The Creation Answers Book], chapter 6, Triune Press, Brisbane, Australia, 1999; and Q&A: Death and Suffering—Curse.

(Also available in Russian)


Give $5 for 5. Although this article may have only taken 5 minutes to read, it could have taken over 5 hours to write. Consider a $5 donation to support our ministry efforts. Support this site

Copied to clipboard
496
Product added to cart.
Click store to checkout.
In your shopping cart

Remove All Products in Cart
Go to store and Checkout
Go to store
Total price does not include shipping costs. Prices subject to change in accordance with your country’s store.