Deep secrets: cetacean communication
Posted on homepage: 16 June 2008 (GMT+10)
Not until the 1940s did serious research begin on the world of underwater animal sounds.1 For the first time, thanks to the underwater microphone, researchers had the clicks, whistles and songs of aquatic mammals at their fingertips. But the hard question of what the animals were communicating has kept researchers busy ever since.
The vocabularies of the cetaceans (whales and dolphins) are stunning. A recent scientific paper made headlines when researchers discovered that dolphins actually use their whistles to tell the names of other individual dolphins,2 and might even refer to a third animal by name in ‘conversation.’
In contrast to most terrestrial mammals, the communications of whales and dolphins are primarily auditory (sound) rather than visual.3,4 This auditory design is ideal because vision is extremely limited underwater (appreciable sunlight extending to only some 200 m (700 ft)5 ). Many fish are vocally uncommunicative, but this does not mean that they are poorly designed. The key is that social aquatic animals rely on auditory communication.4 The cetaceans are social animals and rely on their social structures for ecological survival, whereas most sharks, for example, are quiet loners.
Giant voices for giant creatures
Blue whales are particularly impressive. They use low frequency, intense tones, and have been known to dominate the low frequency sound field of an entire coastal region for months.1 Their calls include extremely deep songs that actually extend into the range of ‘infrasound’, too low for humans to hear.3,6 Infrasound can be heard over extremely long distances—biologists can detect vocalizing whales from hundreds of kilometres away.3 Researchers believe that the songs help orient the whales in long distance travel, both by communicating to other whales, and by listening to the echoes off the ocean floor to give them a sense of geographic position.3
While baleen whales are specialized for low-frequency hearing, the toothed whales are specialized for high frequencies.3 Sperm whales produce intense high-frequency clicks,1 earning them the title of loudest animal on earth.7 The sperm whale ‘devotes about a quarter of its body length’ to the spermaceti organ,8 whose main function is to focus and intensify loud clicks9 (at the equivalent of 170 decibels on land).7,10 What else this organ is used for is still largely unknown, and some have even suggested that it is used as a battering ram in competition with other whales.11 The function of the clicks is a matter of some speculation as well! They are almost certainly used for echolocation,12 a sonar-like system of ‘seeing’ by hearing echoes,13 and there may be other uses.14
Designed to learn
Cetaceans and also seals are unique in another way: they are accomplished vocal learners. Leading researcher Peter Tyack has noted: ‘Humans are the only terrestrial mammal with well-developed abilities of vocal learning.’3 This represents a significant puzzle for an evolutionist. Tyack continues: ‘ … most nonhuman terrestrial animals appear unable to modify their vocal repertoire based upon what they hear. Several groups of marine mammals, including seals, whales, and dolphins, have highly developed skills for vocal learning.’3 The problem for the evolutionists is that the cetaceans are very far from humans in the evolutionist’s ‘family tree’ (called a phylogeny). This means that vocal learning had to evolve independently on land and in the water. Not only that, but evolutionists also believe that cetaceans and seals were land dwellers who entered the sea at different times. That means they had to independently evolve countless specializations for marine life—including the exceedingly unique gift of vocal learning. The evolutionary scenario looks more improbable all the time.15
The case of whales’ abilities to learn sounds is just one example showing that unique characteristics of animals cross the bounds of the evolutionary phylogenies over and over. Biblical creationists would expect animals made by the same Designer to have many similarities (a good design can be used in many settings). Evolutionists often explain these circumstances as ‘convergent evolution’ (evolution just happening to hit upon the same solution twice, independently), but this tends to mask the true situation: the circumstances are not evidence of evolution, but an anomalous fact to be explained away.16 Anomalous facts like this plague the evolutionists’ theories about whales.17 The more logical solution is not convergent evolution, but common design by a Divine Designer, by whom ‘were all things created’ (Colossians 1:16).18
Design explanations are intuitive when discussing the whales’ communication systems. Even evolutionists who don’t believe in a Designer have allowed the word ‘design’ to slip into their writings on the topic. Peter Tyack notes that a number of researchers believe that long-range signals have ‘design features’ for communication.3
Design explanations are not ‘science stoppers,’ as some evolutionists say. As creationists, we recognize that there is a purpose for whales’ communication. We know that on Day 5 of Creation Week, God created the whales perfectly suited for their needs. The belief in a purpose and order in the universe was the driving force that gave birth to the scientific enterprise. As Johannes Kepler said, the ‘secrets [of science] … are set before our eyes like a mirror so that by examining them we observe to some extent the goodness and wisdom of the Creator.’19 What could be more fitting than studying the whales’ signals to discover the purposes for which the Creator designed them? Because we expect to find engineering and design in the whales, creationist scientists have the most hopeful and meaningful impetus for research possible.
References and notes
- Cato, D.H. and McCauley, R.D., Australian research in ambient sea noise, Acoustics Australia 30(1):13–20, 2002. Return to text.
- Zabarenko, D., Dolphins recognise their own name, <www.abc.net.au/science/news/stories/s1634076.htm>, 25 July 2006. Janik, V.M., Sayigh, L.S. and Wells, R.S., Signature whistle shape conveys identity information to bottlenose dolphins, Proc. Nat. Acad. Sci. USA 103(21):8293, 23 May 2006, Epub., 12 May 2006. Return to text.
- Tyack, P.L., Functional aspects of cetacean communication, in Mann, J., et al., eds., Cetacean Societies, University of Chicago Press, Chicago, pp. 270–288, 2000. Return to text.
- Tyack, P.L., Dolphins whistle a signature tune, Science 289:1310–1311, 2000. Return to text.
- The ocean: mankind’s last frontier, Encyclopaedia Britannica and Bantam Books, New York, p. 141, 1978. Return to text.
- Bedard, A.J. and Georges, T.M., Atmospheric infrasound, Acoustics Australia 28(1):47, 50, 2000. Return to text.
- Trivedi, B.P., Sperm whale ‘voices’ used to gauge whales’ sizes, <news.nationalgeographic.com/news/2003/11/1103_031103_tvspermwhale.html>, 26 July 2006. Return to text.
- A more specialized form of the ‘melon’ found in other cetaceans, where it is believed to act as a sound-focusing lens. Return to text.
- Ref. 3, pp. 273–274; see also Whitehead, H., and Weilgart, L., The sperm whale, in Mann et al., eds., ref. 3, pp. 167–168. Return to text.
- Chapman, D.M.F. and Ellis, D.D., The elusive decibel: thoughts on sonars and marine mammals, Canadian Acoustics 26(2):29–31, 1998. Return to text.
- Carrier, D.S. et al., The face that sank the Essex: potential function of the spermaceti organ in aggression, The Journal of Experimental Biology 205:1755–1763, 2002. Return to text.
- Ref. 3, p. 282, and ref. 7. Return to text.
- Ref. 3, pp. 280–283. Echolocation poses basic problems for evolution. See Weston, P., Bats: sophistication in miniature, Creation 21(1):28–31, 1998; <www.creation.com/bats>, and Meyer, A., The world of whales, Creation 19(1):26–29, 1996; <www.creation.com/whale>. Return to text.
- Norris, K.S., and Mohl, B., Can odontocetes debilitate prey with sound?, American Naturalist 122(1):85–104, 1983. Return to text.
- See Sarfati, J., Refuting Evolution, chapter 5, Master Books, Arkansas, USA, 1999. Return to text.
- On convergent evolution, see Menton, D.N., If we resemble apes, does that mean we evolved from apes?, <www.creation.com/apes>, 25 August 2000. Return to text.
- Woodmorappe, J., Walking whales, nested hierarchies, and chimeras: do they exist?, Journal of Creation 16(1):111–119, 2002; <www.creation.com/walkingwhales>. Return to text.
- See <www.creation.com/homologous>. Return to text.
- Quoted in Nickel, J., Mathematics: is God silent?, rev. ed., Ross House Books, California, USA, pp. 115–116, 2001. Return to text.