| Feature Article - November 2001 |
| by Do-While Jones |
Evolutionists say, “whales are one of the better examples of evolution.” Let’s see just how good an example they are.
New fossils have been reported since our August 1999 essay, “In a Whale of Trouble.”
| On page 277 of this issue [Nature Vol. 413], Thewissen and colleagues describe their discovery of partial fossil skeletons from the earliest cetaceans--a group of mammals that today consists of whales, porpoises and dolphins. The fossils, which are some 50 million years old and were found in Pakistan, take us a huge step forwards in understanding the origins and evolutionary relationships of whales. Until now, the limbs of all known early cetaceans reflected an amphibious or wholly aquatic lifestyle. But the newly discovered fossils show that the first whales were fully terrestrial, and were even efficient runners. They also reveal that cetaceans are more closely related to the oldest known even-toed ungulates--a group of hoofed mammals that includes cows, hippos, pigs, camels and giraffes--than to any other mammals. These conclusions are based on solid anatomical data, and contradict the previous hypotheses of both palaeontologists and molecular biologists. 2 |
In other words, Thewissen has found some new fossils that show that what has previously been taught about whales evolving from Mesonychids is wrong. The fossils he found were of an animal called Pakicetus. Creatures like Pakicetus are called “pakicetids.”
| Pakicetids, which existed in the early Eocene epoch, some 50 million years ago, are the earliest known cetaceans [whales, etc.]. But, until now, only the skulls of these animals had been described. Cetaceans from the middle Eocene, 45 million years ago, have been known for more than a century, but here, too, few limb remains were discovered, until about 20 years ago. Since then, numerous fossils from North America, Pakistan and Egypt have revealed that these early cetaceans had mobile elbows and external hindlimbs with articulated knees. However, they were already fully aquatic, except for Ambulocetus, which was amphibious--much like sea lions. So there was no detailed information about the anatomy of the cetaceans' terrestrial ancestor. 3 |
Until recently, everything we have known about pakicetids has been based entirely on skulls. On the PBS program, Phillip Gingrich explained how he found the first Pakicetus skull 30 years ago. He didn’t find any “postcranial bones” (bones below the skull). He thought he had found the skull of a wolf, but it had a structure that looked like the middle ear of a whale. Therefore, he assumed that he had found an ancestral whale. He probably believed that the body, if he found it, would be something like a small whale.
| Recent cetaceans [modern whales and dolphins] are very different to other mammals, so another question that has dogged this field is that of which group of mammals contains their closest relatives--which is their "sister group"? The cranial and skeletal anatomy of cetaceans is highly modified compared with that of land mammals, and fossils of early cetaceans are so rare and generally incomplete, that the affinities of the group are difficult to establish. On the basis of tooth and ear morphology, palaeontologists contend that cetaceans are most closely related to the mesonychians--a group of extinct ungulates from the early Tertiary. But molecular biologists favour hippos--which form one of the families of modern even-toed ungulates (artiodactyls)--as the sister group. 4 |
Translation: Modern whales don’t look very much like land animals, so it is hard to imagine what land animals they are closely related to. Whale skulls and skeletons are so different from land animals that evolution must have changed them very much. Furthermore, there are so few ancient whale fossils that we don’t really have much to compare with other animals. The shapes of their teeth and ears lead paleontologists to say whales must be related to wolf-like mesonychians. But the DNA evidence is strongly against this. So molecular biologists say whales evolved from a cow-like (or hippo-like) artiodactyl.
| Thewissen and colleagues' discovery allows us to address both of these problems. The newly found fossils include several skulls and postcranial bones from two early pakicetid species--which, it seems, had the head of a primitive cetacean (as indicated by the ear region) and the body of an artiodactyl. All the postcranial bones indicate that pakicetids were land mammals, and it is likely that they would have been thought of as some primitive terrestrial artiodactyl if they had been found without their skulls. Many of the fossils' features--including the length of the cervical vertebrae, the relatively rigid articulations of the lumbar vertebrae, and the long, slender limb bones--indicate that the animals were runners, moving with only their digits touching the ground. 5 |
Translation: The new fossils include body bones with the skulls, so we now know what Pakicetus really looked like. It looked just like a land mammal. Not only that, it looked just like a land mammal that could run very well. If it had been found without a skull, nobody would have thought that it was a whale ancestor. The only thing about this creature that is even remotely whale-like is the middle ear portion of the skull.
Not only do the new Pakicetus fossils not look like modern whales, they don’t look like the other links in the alleged evolution of the whale. The current story is that Pakicetus evolved into Ambulocetus, which evolved into Rodhocetus, which evolved into Basilosaurus. Thewissen’s new fossil discoveries show that Pakicetus has practically nothing in common with Ambulocetus or Basilosaurus.
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Aquatic postcranial adaptations are pronounced in late Eocene basilosaurids and dorudontids, the oldest obligate aquatic cetaceans for which the entire skeleton is known, and therefore can be used to evaluate pakicetid morphology. Aquatic adaptations of basilosaurids and dorudontids include: presence of short neck vertebrae; thoracic and lumbar vertebrae that are similar in length; unfused sacral vertebrae; lack of a sacro-iliac joint; presence of a short tail with a ball-vertebra (a vertebra at the base of the fluke, with convex articular surfaces); broad fan-shaped scapula with anterior acromion and small supraspinous fossa; an ulna with a large and transversely flat olecranon; a wrist and distal forearm flattened in the plane of the hand; and tiny hind limbs.
Pakicetids display none of these features. 6 |
Thewissen assumes these significant differences are due to “pronounced adaptations.” In other words, he thinks there must have been an awful lot of evolution going on in a very short time because the bodies of Pakicetus and Basilosaurous bear practically no resemblance to each other. Another, perhaps more logical explanation for the significant differences, is that they aren't related to each other at all.
| But the most eloquent information provided by the fossils comes from the ankle bones, particularly the astralagus. This has two pulleys, which connect to both the tibia and the more distal ankle bones and allow a great deal of flexibility. This type of morphology is an adaptation for running. It was once thought to be unique to artiodactyls, but it is now clear that it also occurred in cetaceans. So, for the first time, morphological evidence shows that artiodactyls are the closest relatives of the cetaceans. 7 |
Did you follow that logic? Don’t feel bad if you didn’t. It wasn’t very logical. Pakicetus has ankle bones just like artiodactyls, which are land mammals that run very well. This isn’t very surprising to us because Pakicetus apparently was a land animal that could run very well. Pakicetus wasn’t a whale, or even remotely like a whale. But the name “Pakicetus” means “whale found in Pakistan.” Therefore, it is by definition, a cetacean (a whale). Since Pakicetus has arbitrarily been called a whale, and since it is related to the artiodactyls, therefore all whales evolved from artiodactyls. Anyway, that’s their logic.
| What causes scientists to declare the creature [Pakicetus] a whale? Subtle clues in combination--the arrangement of cusps on the molar teeth, a folding in a bone of the middle ear, and the positioning of the ear bones within the skull--are absent in other land mammals but a signature of later Eocene whales. 8 |
The only parts of Pakicetus that look like a whale are the teeth and the ears. Everything else looks different. If we were to apply homology objectively, then we would have to say that, on the whole, the evidence is that there is no relationship. But what about the teeth and ears? Are they really similar?
| Deep, near-vertical gouges constitute most of the dental wear in pakicetids. Cladistic arguments have been used to link this wear pattern to aquatic predation on fish, but no functional model or modern analogue is known. Moreover, this kind of dental wear also occurs in raoellid artiodactyls. Although this dental wear probably represents a distinctive way of food processing, it does not necessarily imply aquatic life. 9 |
So, whales aren’t the only kinds of creatures that have teeth like this. Some land animals do, too. Actually, ancient whale teeth are more like the teeth of mesonychids, which is no longer believed to be the ancestor of whales. Therefore, this similarity has to be explained away.
| Although there is a general resemblance of the teeth of archaeocetes [ancient whales] to those of mesonychids, such resemblance is sometimes overstated and evidently represents evolutionary convergence. 10 |
“Evolutionary convergence” means “coincidence.” It is the term evolutionists use for things that look like they evolved from a common ancestor, but don’t fit into their theory. They claim that two entirely different creatures evolved the same feature because they both lived in the same environment and both needed the functionality this feature provides. In other words, looks are deceiving in this instance. This is yet another example of how, when the similarity doesn’t support the desired conclusion, the similarity is dismissed.
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Unlike any other cetacean, the pakicetid outer ear was unspecialized and similar to that of land mammals. The external auditory meatus opens low on the side of the skull, and the mandible has a small mandibular foramen. In amphibious mammals, the external auditory meatus commonly opens dorsally. The mandibular foramen of late Eocene and Neogene cetaceans is large and transmits underwater sound to the middle ear. Enlargement also occurs in Ambulocetus, but the foramen is small in pakicetids.
The pakicetid middle ear was highly specialized and included pachy-osteosclerotic ossicles, an involucrum and a plate-like sigmoid process. These features have been interpreted as adaptations for underwater hearing, and it has been suggested that the presence of an involucrum facilitates underwater high-frequency transmission in modern odontocetes even though the involucrum is also present in low-frequency mysticetes. In the case of pakicetids, the absence of air sinuses insulating the ears, the firm fusion of the periotic to the surrounding bones, and the presence of a flat tympanic membrane suggest that reception of airborne sound is well developed, but are inconsistent with good underwater hearing. It is most likely that the specializations of the pakicetid middle ear are analogous to those of some subterranean mammals and are related to the reception of substrate-borne vibrations or sound when the head is in contact with the ground. Turtles are in close contact with the substrate and gather sensory information using this method. 11 |
Thank you for suffering through those two paragraphs. All he said was that Pakicetus ears aren’t really like whale ears after all. We could have said it just that simply, but we wanted you to hear it straight from an evolutionary expert.
| Thewissen et al.'s discovery of these terrestrial cetaceans ["land-walking whales"] is one of the most important events in the past century of vertebrate palaeontology. Only a very few fossils, such as these, reveal a link between two groups of vertebrates that are hugely different in terms of shape yet closely related in terms of evolution. When there is a drastic shift in habitat--such as from land to water--the morphology of the newly adapted animals is generally so greatly modified, because of the high selective pressure, that any resemblance to the original ancestor is quickly obliterated. But the new fossils superbly document the link between modern whales and their land-based forebears, and should take their place among other famous 'intermediates', such as the most primitive bird, Archaeopteryx, and the early hominid Australopithecus. 12 |
These fossils actually revealed a lack of connection between land mammals and aquatic mammals. The resemblance wasn’t “quickly obliterated.” It was never there to begin with. But this lack of resemblance is cited as evidence for evolution! Why? Because this is one of “only a very few fossils” that had a snowball’s chance of being a transitional form. They can’t afford to let it melt away.
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At what stage did they come up with extra myoglobin in their muscles for storing oxygen on longer dives? When did humpbacks start singing one of the most elaborate, evocative songs ever heard? Because changes in physiology and behavior aren’t always associated with obvious shifts in anatomy, they can be harder to track. We only know that when modern whales emerged, they continued to refine their adaptations and prosper.
The diagram of the whale family tree remains far from finished. Many branches need to be filled in, and a revision lately has been suggested for the roots. 13 |
One of the many things that make whales different from land mammals is that they are able to store oxygen in their muscles for long periods of time, allowing them to remain underwater far longer than any land mammal can. They either acquired it through evolution, or were created that way to begin with. But even though there isn’t any explanation for how they could have acquired extra myoglobin, National Geographic hasn’t lost the faith. They are still convinced they acquired it through evolution.
They know that many branches of the tree are missing. They know that what they once thought was the root of the tree has been pulled out of the ground and thrown on the fire. Despite this they “know” that modern whales emerged and continued to refine their adaptations.
Evolutionists say, this is “one of the better examples of evolution.” If that’s all they have, the theory of evolution is in deep, deep water.
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Footnotes:
1
Chadwick, National Geographic, November 2001, “Evolution of Whales”, page 69
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2
Muizon, Nature, Vol. 413, 20 September 2001, “Walking with whales”, page 259 https://www.nature.com/articles/35095137
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3
ibid.
4
ibid. page 260
5
ibid.
6
Thewissen, et al., Nature, Vol. 413, 20 September 2001, “Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls”, page 227 https://www.nature.com/articles/35095005
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7
Muizon, Nature, Vol. 413, 20 September 2001, “Walking with whales”, page 259 https://www.nature.com/articles/35095137
(Ev)
8
Chadwick, National Geographic, November 2001, “Evolution of Whales”, page 68
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9
Thewissen, et al., Nature, Vol. 413, 20 September 2001, “Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls”, page 227 https://www.nature.com/articles/35095005
(Ev)
10
Gingerich, et al., Science, Vol. 293, 21 September 2001, “Origin of Whales from Early Artiodactyls: Hands and Feet of Eocene Protocetidae from Pakistan”, page 224 https://www.science.org/doi/10.1126/science.1063902
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11
Thewissen, et al., Nature, Vol. 413, 20 September 2001, “Skeletons of terrestrial cetaceans and the relationship of whales to artiodactyls”, page 227 https://www.nature.com/articles/35095005
(Ev)
12
Muizon, Nature, Vol. 413, 20 September 2001, “Walking with whales”, page 259 https://www.nature.com/articles/35095137
(Ev)
13
Chadwick, National Geographic, November 2001, “Evolution of Whales”, page 76-77
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