http://www.answersingenesis.org/home/area/re1/chapter5.asp
Cetaceans (whales and dolphins) are actually mammals, not fish. But they live their whole lives in water, unlike most mammals that live on land. But evolutionists believe that cetaceans evolved from land mammals. One alleged transitional series is prominently drawn in Teaching about Evolution and the Nature of Science. This chapter analyzes this and other arguments for cetacean evolution, and shows some of the unique features of whales and dolphins.
Wonderful whales
Cetaceans have many unique features to enable them to live in water. For example:
Enormous lung capacity with efficient oxygen exchange for long dives.
A powerful tail with large horizontal flukes enabling very strong swimming.
Eyes designed to see properly in water with its far higher refractive index, and withstand high pressure.
Ears designed differently from those of land mammals that pick up airborne sound waves and with the eardrum protected from high pressure.
Skin lacking hair and sweat glands but incorporating fibrous, fatty blubber.
Whale fins and tongues have counter-current heat exchangers to minimize heat loss.
Nostrils on the top of the head (blowholes).
Specially fitting mouth and nipples so the baby can be breast-fed underwater.
Baleen whales have sheets of baleen (whalebone) that hang from the roof of the mouth and filter plankton for food.
Many cetaceans find objects by echo-location. They have a sonar system which is so precise that it's the envy of the U.S. Navy. It can detect a fish the size of a golf ball 230 feet (70 m) away. It took an expert in chaos theory to show that the dolphin's ‘click’ pattern is mathematically designed to give the best information.1
One amazing adaptation of most echo-locating dolphins and small whales is the ‘melon,’ a fatty protrusion on the forehead. This ‘melon’ is actually a sound lens—a sophisticated structure designed to focus the emitted sound waves into a beam which the dolphin can direct where it likes. This sound lens depends on the fact that different lipids (fatty compounds) bend the ultrasonic sound waves traveling through them in different ways. The different lipids have to be arranged in the right shape and sequence in order to focus the returning sound echoes. Each separate lipid is unique and different from normal blubber lipids, and is made by a complicated chemical process, requiring a number of different enzymes.2
For such an organ to have evolved, random mutations must have formed the right enzymes to make the right lipids, and other mutations must have caused the lipids to be deposited in the right place and shape. A gradual step-by-step evolution of the organ is not feasible, because until the lipids were fully formed and at least partly in the right place and shape, they would have been of no use. Therefore, natural selection would not have favored incomplete intermediate forms.
Missing links
Evolutionists believe that whales evolved from some form of land mammal. According to Teaching about Evolution, page 18, they ‘evolved from a primitive group of hoofed mammals called Mesonychids.’
However, there are many changes required for a whale to evolve from a land mammal. One of them is to get rid of its pelvis. This would tend to crush the reproductive orifice with propulsive tail movements. But a shrinking pelvis would not be able to support the hind-limbs needed for walking. So the hypothetical transitional form would be unsuited to both land and sea, and hence be extremely vulnerable. Also, the hind part of the body must twist on the fore part, so the tail's sideways movement can be converted to a vertical movement. Seals and dugongs are not anatomically intermediate between land mammals and whales. They have particular specializations of their own.
The lack of transitional forms in the fossil record was realized by evolutionary whale experts like the late E.J. Slijper: ‘We do not possess a single fossil of the transitional forms between the aforementioned land animals [i.e., carnivores and ungulates] and the whales.’3
The lowest whale fossils in the fossil record show they were completely aquatic from the first time they appeared. However, Teaching about Evolution is intended as a polemic for evolution. So it reconstructs some recent fossil discoveries to support the whale evolution stories that Slijper believed on faith. On page 18 there is a nice picture of an alleged transitional series between land mammals and whales (drawn at roughly the same size without telling readers that some of the creatures were hugely different in size—see the section about Basilosaurus in this chapter). This appears to be derived from an article in Discover magazine.4 The Discover list (below) is identical to the Teaching about Evolution series except that the latter has Basilosaurus as the fourth creature and the Discover list has ‘dates’:
Mesonychid (55 million years ago)
Ambulocetus (50 million years ago)
Rodhocetus (46 million years ago)
Prozeuglodon (40 million years ago)
One thing to note is the lack of time for the vast number of changes to occur by mutation and selection. If a mutation results in a new gene, for this new gene to replace the old gene in a population, the individuals carrying the old gene must be eliminated, and this takes time. Population genetics calculations suggest that in 5 million years (one million years longer than the alleged time between Ambulocetus and Rodhocetus), animals with generation lines of about ten years (typical of whales) could substitute no more than about 1,700 mutations.5 This is not nearly enough to generate the new information that whales need for aquatic life, even assuming that all the hypothetical information-adding mutations required for this could somehow arise. (And as shown in chapter 9, real science shows that this cannot occur.)
... article continues... to to the page to see it