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Whale Evolution: a Whale of a Tale Creation Research Society Quarterly 2012. 49:122–134. 122 Creation Research Society Quarterly Whale Evolution: A Whale of a Tale Jerry Bergman* Abstract review of the evolution of whales from terrestrial land animals finds A that the evidence used to support the current theory is either wrong or very questionable. A focus is on the hip bone and fetal teeth evidence because they are commonly used as proof for the land mammal-to-whale evolution theory. The putative fossil evidence for whale evolution from terrestrial animals is also evaluated, concluding that the examples used are likely all extinct mammals and not transitional forms. Introduction be only about 20 feet long, but baleen A major problem has been deter- The term “whale” is a common noun and blue whales can grow up to 100 feet mining which terrestrial animal whales that can refer to all marine mammals long. Toothed whales are, on average, evolved from. Charles Darwin proposed called cetaceans (members of order smaller then baleen whales, ranging one of the first theories of whale evolu- cetacea), including dolphins and por- from 3 to 32 feet long, although most tion, suggesting they evolved from bears. poises. In this paper the term “whales” are from 10 to 30 feet long. Blue whales He wrote, “I can see no difficulty in a excludes both dolphins and porpoises. can weigh up to 150 tons. race of bears being rendered, by natural Classification of whales divides them selection, more and more aquatic in into two groups; toothed whales and their structure and habits, with larger baleen whales, the latter of which use The Origin of Whales and larger mouths, till a creature was large brush-like structures to filter food The evolution of whales is one of the produced as monstrous as a whale” from the ocean. most difficult evolutionary enigmas, and (Darwin, 1859, p. 184). Other theories Toothed (odontoceti) whales are di- numerous theories have been proposed. include proposals that whales evolved vided into six main families: pilot whales, Historically, whales were classified as from a cow-like animal, a hippopotamus- fin whales, minke whales, blue whales, fish. It was only when Linnaeus changed like animal, a hyena-like animal called humpback whales, narwhal whales, and his original classification and reclassi- a pachyaena, a wolf-like animal called delphinidae, such as dolphins and killer fied them as mammals that their origin pakicetid, a primitive group of hoofed whales (orca). Baleen whales (suborder became an issue (Slijper, 1962). One animals called mesonychids, or even a Mysticeti) are divided into three main current theory is that marine animals catlike animal called a sinonyx. families, right whales, rorqual whales, evolved into terrestrial animals; then The hippo theory, long the leading and gray whales. Of the 76 known whale whales evolved from a terrestrial ungu- candidate because of its DNA similari- species, 66 are toothed whales, and 10 late ancestor (or from some extinct wolf- ties with whales, has recently lost favor are baleen whales. Some species grow to like animal) back into a marine animal. because the proposed hippo precursor lived too recently and in the wrong part of the world to be a whale ances- tor. Since the 1960s, another popular proposal (based on dental similarities * Jerry Bergman PhD, Biology Department, Northwest State College, Archbold, OH and molecular data) has been that Accepted for publication March 3, 2012 whales evolved from hoofed, carnivo- Volume 49, Fall 2012 123 rous mammals called mesonychians, specifically an extinct archaic ungulate (e.g., Thewissen et al., 1998; Harder, 2001). New findings, though, have placed mesonychians in the artiodacty family (even-toed ungulates including camels, hippos, pigs, and ruminants) based on Artiocetus clavis and Rodhoce­ tus balochistanems fossils (Milinkovich and Thewissen, 1997). Others argue that mesonychians cannot be ancestor to whales for several reasons, including all “phylogenetic studies indicate that pakicetids are more closely related to living cetaceans than to artiodactyls and mesonychians” (Thewissen et al., 2001). The latest theory, proposed in 2007 (see Figure 1), is that whales evolved from an Indohyus, a putative 48 million-year- old terrestrial animal the size of a small raccoon that looked like an antler-less Af- rican mouse long-tailed deer (Thewissen, et al., 2007). Some have even described this animal as an overgrown, long-legged rat, looking nothing like a whale. The main evidence it was a whale ancestor is Indohyus’s thickened ear bone, a feature that so far has been seen only in Indohyus and cetaceans (Thewissen, et al., 2007). All of these proposed theories have some support but also problems. For example, whale evolution from artio- dactyls is supported mainly by DNA se- quences yet this is problematic because all artiodactyl teeth have three lobes, a trait lacking in both cetaceans and me- Figure 1. Drawings of the skeletons of one proposal of whale evolution from the sonychians. Thus, this lineage would re- first putative whale to the modern whale. The skeletons are shown on the right. quire a complicated tooth evolution that On the left is the approximate proportions of the animals themselves. The modern “includes reversals, convergences or both” Baleen whale superimposes the skeleton on the size illustration to save space. Note (Milinkovich and Thewissen, 1997, p. the first putative animals in the evolution of whales are extremely small compared 623). Ellis (1987, p. 8) concluded that to modern-day whales, a fact obscured when the fossils are shown as a set. This “all known fossil whales seem to be fully is also a major problem for the theory of whale evolution. The animals, starting developed aquatic mammals; we do not from the bottom, are Indohyus, Pakicetus, Ambulocetus, Rodhocetus, Dorudon, know the steps that led to their return to and at the top, the modern whale Balaena. (Illustration courtesy of Richard Geer) the sea.” This conclusion still holds true. Evolution from Terrestrial Mammals evolutionists typically hypothesize that that transformation of a land tetrapod Evolutionists have always faced the prob- they evolved from some type of terrestrial into a sea mammal requires virtually lem that whales are mammals. Thus, mammal. A problem with this view is all of the tetrapod’s hundreds of major 124 Creation Research Society Quarterly land-adapted traits to be converted 2. Weight-bearing: Land-dwelling ence thirst, a sensory system not needed into sea-adapted designs. Nonetheless, animals consume about 40 percent of by sea-dwelling creatures. In contrast, whale evolution directly from a fish ap- their energy just to move their bodies, marine animals also need to regulate pears even less probable because of the but sea-dwelling creatures use water for body water, but they must do so in very enormous differences between fish and support (Zahn, 1988, p. 28). For this different ways than terrestrial animals. whale anatomy and physiology. As ex- reason the transition from land to water 5. Kidneys: Because water has to be ample, fish use gills for breathing while requires major muscular and skeletal used economically by terrestrial animals, whales use lungs; fish typically lay eggs, system design changes. Whales must they require an efficient kidney system. and whales breastfeed and give birth to not only lose their legs but also evolve The body’s protein metabolism system live young. flippers, pectoral fins, a fluke, and an either excretes or converts wastes. The Other problems with current pro- aerodynamic design, plus a brain and metabolic breakdown of protein pro- posal of whale evolution include the an appropriate nervous system to meet duces ammonia, which is toxic and is radical changes required in the integu- the needs of these many new structures therefore converted into urea, in the end ment system, lactation, breathing, div- and their requirements. reducing the amount of water excreted. ing, feeding methods, nervous system, 3. Heat Retention: Land tempera- In addition, a system of ducts and other eyes (they must be protected in water) tures often change rapidly and can fluc- structures are required for the kidney’s and hearing, and transformation from tuate over a wide range. For this reason, functioning. Sea-dwelling organisms, a walking to a swimming mode of life. land-dwelling organisms must possess a in contrast, discharge waste materials, Some additional examples include loss physical mechanism that can withstand including ammonia, directly into their of body hair, body streamlining, trans- enormous temperature fluctuations. aquatic environment. In short, in order formation of forelimbs into flippers, loss Not only do the temperature changes to evolve from water to land, living of hind limbs, evolution of flukes for in the sea occur very slowly and within things would have had to develop whole swimming, and backward movement a much narrower range, but the water new organ systems to deal with water of nostrils. Thousands of changes are is also much colder, and water has high regulation. Then, to evolve back into required to convert a land tetrapod to thermal conductivity, a major problem aquatic animals, another entirely new a fishlike mammal. All of these systems for warm-blooded mammals (Heyning system must be evolved especially to deal are interrelated and function as a unit, and Mead, 1997, p. 1138). Organisms with salt removal, since whales live in a requiring altering the interrelationships with a body system regulated according toxic saltwater world. of the whole system. Yet other changes to land temperature demands would 6. Breathing Opening: Terrestrial required for a large dog-sized tetrapod need to evolve a whole new protective animals breathe through their nose and animal to evolve into a whale include system to deal with very cold ocean water mouth. In contrast, whales have a the following: temperatures.
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