Dr. John Morris, president of the Institute for Creation Research is at it again. Apparently not content with advertising his abject ignorance of zoology as he did a few months ago when he listed tunicates (phylum chordata) along with sea stars as members of the phylum echinodermata, he is now letting everyone know that he is equally incompetent to comment intelligently on the subject of paleontology (I know, I am as shocked as you are).
More specifically he has come out attacking the classic fossil evidence for the evolution of the horse in the September (2008) issue of ICR’s Acts & Facts.
Morris: Horse evolution prominently appears in textbooks as a supreme example of the evolution of one body style into another. All students remember the “horse series” sketches, tracing the development of a small browser named Hyracotherium (formerly known as Eohippus) with four toes on the front feet and three on the rear, into the large one-toed horse of today. Intermediate steps included the three-toed Mesohippus, a modified horse with one toe touching the ground… [Emphasis mine]
Wrong right off the bat. The fact is that with Mesohippus all three toes touch the ground as can be seen in the above photo of a mounted fossil at the Chicago Field Museum. This is especially true when it is taken into account that Mesohippus probably would have had pads on its feet similar to those found in tapirs.
Morris: …the one-toed Merychippus; Pliohippus, also with only one toe; and finally our modern horse, Equus, who along the way had acquired high-crowned molars and other adaptations.[Emphasis mine]
Merychippus was not one-toed, it was three toed like Mesohippus, though its side toes were more reduced in size. They are even visible in the illustration Dr. Morris used in his article (which he may have taken from an NCSE publication which rebutted many of the common creationist claims about the fossil record of the horse):
Here is a larger, more detailed, illustration of the foot bones of Merychippus:
Morris: Of course, modern horses exist in great variety, with many unusual adaptations that allow them to cope with widely varied environments. Numerous species are recognized, almost all of which are known to hybridize. Obviously, there is a great deal of latitude in horse characteristics.
All modern ‘horses’ (horses, zebras, asses) in fact belong to a single genus, Equus, and are, relatively speaking, fairly similar. Equus is the sole surviving genus of a once much more diverse Family, equidae, which is made up of as many as 30 different genera.
Morris: Furthermore, various strains can be bred to accentuate one trait, such as the tiny horses about as large as a dog. Horses display a great deal of adaptability.
But no breed of living horse (or ass or zebra) displays the sets of characteristics found in the extinct genera. Big or small they are all still Equus.
Morris: Early evolutionary theories hypothesized progress in a direct line from one type to another, and fossils were displayed within that framework. In recent decades, this view of directed evolution has been generally disavowed, and no particular form is now considered to have been the goal of “non-directed” mutation and natural selection. Once free to examine the data without this “directed” overprint, evolutionary scientists were quick to recognize that changes among horses had been abundant, extensive, and unpredictable.
There are some things to note, however. During the same time period that some of the descendants of Hyracotherium supposedly developed into full-blown horses and elephants and other mammals, others persisted unchanged. [Emphasis mine]
While current thinking among most paleontologists is that the historically recognized genus Hyracotherium is paraphyletic (that fossils that should have been classified as separate genera have been lumped together), and that only some of these (Eohippus) are in fact in the horse Family (the others belonging to other related Families of the same Order, perissodactyla) (Rose & Archibald 2005), no paleontologist that I am aware of, past or present, has considered any of the “Hyracotherium” species to be ancestral to elephants (Order proboscidea) and it is certainly not the current view among paleontologists that this is the case.
I cannot say for certain why Dr. Morris would suggest that they were (he didn’t get it from a standard zoology or paleontology text) but I do have a hypothesis which I will discuss in a few moments.
Morris: It seems that evolution does not always change things–often it leaves them alone. Selection pressures that acted so strongly to produce major modifications in some life forms left others in stasis.
First, Dr. Morris doesn’t make reference to any actual fossils here, so there is no way to judge whether what he is saying is accurate or not, and one should always check, especially with creationists.
For example, creationists often talk about a type of lob-finned fish called coelacanths which scientists had thought to have gone extinct at the end of the Cretaceous period some 70 million years ago (until 1938 when some were found still living of the coast of Africa). Creationists point to the coelacanth and say things like: “look coelacanths haven’t changed in 70 million years (years we don’t believe existed), more proof that evolution doesn’t happen”.
For example Macropoma, which belongs to the same Family (Latimeriidae), is only about a third the size of Latimeria, and there are also a few other differences in the details of their outward anatomy. There were probably many genetic, physiological, and even behavioral differences as well but those don’t fossilize so it would be difficult for us to know. And although Latimeria is similar to some Cretaceous genera, there are earlier coelacanths that were much less similar in appearance (though still recognizable as belonging to the same Order).
Fossils belonging to the Order Coelacanthini first appear in the fossil record during the Middle Devonian period (about 390 million years ago) and are last found in rocks from the end of the Cretaceous period, however they seemed to have reached their peak of diversity during the Triassic (about 248 to 206 Million Years Ago) (Forey 1998, p. 245). However, despite having been given the colorful moniker of “living fossil”, the living genus Latimeria is not represented in the fossil record at all.
All that being said it should also be understood that evolutionary theory does not require that a group of organisms (like coelacanths or equids) must change radically over time. If a successful phenotype (shape, physiology, & behavior) is evolved then as long as it remains successful there is no reason it must change. Evolutionists have been telling creationists this for a hundred years (every time they bring up something like the coelacanth), maybe it’s finally starting to sink in.
Morris: Their fossils are found in the same strata intervals, so they must have lived in the same environment.
The term “same strata intervals” is problematic here. Yes, different lineages of equid coexisted during several periods of the Cenozoic, but just because they were found in strata of comparable age does not necessarily mean that they lived in the same environments. In fact changes in the dentition of some lineages seems to indicate that many were living in different environments (forested areas vs. grasslands).
Morris: Evolution apparently does not apply across the board. If a theory can accommodate any possibility, it is a weak concept indeed.
What nonsense. Just because different lineages evolved along separate trajectories doesn’t mean that “any possibility” can be accommodated by evolutionary theory. How about this Dr. Morris, why don’t you go out and find us a Mesohippus fossil buried in Permian age strata? That would be difficult to explain under our current understanding of how the evolution of mammals proceeded.
Morris: It is now acknowledged that horse evolution as recorded in the fossils follows no recognizable pattern, and that the evolutionary “tree” looks more like a multi-branching “bush.”
No, there is still a “recognizable pattern”, just not a simple straight-line Hyracotherium to Equus pattern. “Bushes” still have roots and branching limbs. In reality the equid Family is just one small branch on the bush of life.
Morris: The successive forms indicating straight-line evolution appear only in textbooks; they do not appear in the fossils.
This is not to say that there was not an ancestor descendant relationship between various species of equid over geologic time. If we knew the exact lineage (something virtually impossible to determine in fossils) from a Hyracotherium grade equid to modern Equus we could theoretically line them up from ancient ancestor to modern descendant and excluded any side-branches and it would look very much like the ‘textbook’ illustration of the horse lineage.
The reason modern evolutionary biologists frown upon the old style horse evolution illustrations is not because there is some doubt about the fact that horses evolved, it is because they give the false impression that A) evolution primarily proceeds via anagenesis rather than cladogenesis (straight lines rather than branching ones), and B) that we know with certainty that the fossil types represented in the illustrations follow direct ancestor/descendant relationships. In other worlds Mesohippus might be the great-great aunt of Merychippus rather that the great-great grandmother. However just because we can’t be certain of which doesn’t mean they are not in the same family.
Morris: Sometimes fossils of different types that supposedly lived at different times appear together in the same strata layer.
Sure, there is often overlap in fossil types. This is a problem only in the minds of creationists who are stuck on the idea that evolution proceeds through straight-line anagenesis with the parent species going extinct as soon as it gives rise to a daughter species. To extend the family metaphor they seem to believe that under evolutionary theory you can’t have any aunts, uncles or cousins and that your mother must die during childbirth. But that is not how evolution works.
Morris: In Oregon, the three-toed grazer Neohipparion (very much like Merychippus) has been found with Pliohippus.
“Very much like” is again a problematic statement. Neohipparion was perhaps “very much like” Merychippus when compared to Hyracotherium or Equus, but there were still important differences. For example as the photograph below illustrates the teeth of Neohipparion were more hypsodont (high crowned) than those of Merychippus, which was one of the earliest grazing equids.
Morris: In the Great Basin area, Pliohippus has been found with the three-toed Hipparion throughout the timeframe supposedly represented. Evolutionary scientists freely admit this situation–and to their credit often attempt to correct the misconceptions–but still the horse series appears in the textbooks.
I love this part: “evolutionary scientists freely admit this situation” as if it were a problem of some kind that paleontologists have been forced recently to ‘admit’ to. It isn’t. Paleontologists have simply described what they find in the fossil record and the overlap Morris describes here is old, old, news.
For example the graph below showing the geologic range of various fossil equids comes from a paper written in 1926 (Matthew 1926) and clearly shows that the genera in question overlap in time. Note however that the earliest Merychippus (the earliest grazing equid) predates the earliest Hipparion, Neohipparion and Pliohippus:
Morris: Any three fossils can be placed in a line and an evolutionary story can be told about the transformation of one into the other. And a different story could be told if the fossils were arranged in a different order.
This is nonsensical hand waiving. The fact is these are not just any fossils and they are not being arbitrarily lined up. These are fossil bearing a number of detailed similarities and lined up in the order in which they first appear in the fossil record (see geologic range chart above).
Evolution coherently explains why we find fossils with anatomical similarities arranged in the fossil record in this pattern. Creationism has nothing but desperate ad hoc silliness like some equids ran from the rising waters of Noah’s Flood faster than others.
Some young earth creationists seem to have realized that their standard position of horse evolution (that being expressed by Morris in his article) is untenable and have admitted that there is good evidence for there being a descent relationship between the various fossil equids and instead argue the equally untenable position that they represent rapid post Noachian Flood diversification of the horse “baramin” (a Bible-babble word for “kind”):
Even though many creationists have strongly criticized the equid fossil record, our present baraminological analysis actually supports the validity of this stratomorphic series. Using the baraminic distance correlation method of Robinson and Cavanaugh , we find significant similarity among all nineteen fossil horse species in our study [a fairly standard line-up from Hyracotherium to Equus – T.B.] but we find no evidence of discontinuity. Although some species in our dataset are negatively correlated, the linear structure of the equids as revealed by 3D ANOPA accounts for these negative correlations. We conclude that all nineteen species included in our analysis belong to the same monobaramin, which we interpret as a record of post-Flood intrabaraminic diversification. (Cavanaugh et al. 2003, p.147, emphasis mine)
So Dr. Morris, it’s not just evolutionists who recognize the evidence for horse evolution found in the fossil record.
Morris: It is interesting to note that Hyracotherium was so named because its specimens looked similar to the hyrax.
The general form of the skull was probably intermediate in character between that of the Hog and the Hyrax. The large size of the eye must have given to the physiognomy of the living animal a resemblance to that of the Hare and other timid Rodentia.
Without intending to imply that the present small extinct Pachyderm was more closely allied to the Hyrax than as being a member of the same order, and similar in size, I propose to call the new genus which it unquestionably indicates, Hyracotherium, with the specific name leporinum. (Owen 1841, emphasis mine)
[Start cut-n-paste from an earlier post (with some added graphics), because creationists refuse to learn.]
The Order Owen is referring to here is “Pachydermata” (after Cuvier) which is no longer considered a valid taxon. It included elephants (obviously), a variety of even-toed ungulates (cows, deer, hippos, pigs etc.), odd-toed ungulates (tapirs, rhinoceros and horses), and the hyraxes. So his placing Hyracotherium in the same order as hyraxes wasn’t really saying much for their being all that similar.
Further evidence that Owen did not see a particularly close resemblance between Hyracotherium and hyraxes came a few years later when he wrote a paper in which he attempted to refine Cuvier’s classification of “Pachyderms” (Owen 1848). In this paper Owen divided the “ungulatata” up into three different groups, the Proboscidia (elephants), the Artiodactyla (even-toed), and Perissodactyla (odd-toed) and he gave a list of examples of each of these and here is where it gets real interesting (ibid. p.139):
As you can see, in the list of Artiodactyls (even-toed ungulates) Owen lists Hyracotherium. In the Perissodactyla (odd-toed ungulates) he lists the hyrax and, of course, the horse (Equus).
So Owen placed Hyracotherium in one branch of the Order and hyraxes and horses in the other. If anything this would imply that he thought hyraxes and horses were more similar to each other than either was to Hyracotherium. He was wrong of course, but again, all he had of Hyracotherium was a crushed partial skull and a jaw fragment, so he can be forgiven. Modern creationists, on the other hand, have the benefit of all the knowledge we’ve gained since Owen’s time (if they chose to avail themselves of it), so they have no excuse except intellectual dishonesty. [End cut-n-paste]
Morris: This little “rock badger” can be seen alive in many zoos, complete with an interpretive sign listing its varied evolutionary antecedents. It looks very, very different from a horse, but most of its reputed predecessors could possibly be true variants of the horse.
This is a nasty little bit of what my friend Ed Brayton likes to call “virulent ignorance“. In this case it is the claim that Hyracotherium either is a hyrax (“rock badger”) or is nearly identical to them. Creationists like Dr. Morris could easily learn the facts by opening a few books, or lacking that much scientific curiosity, they could at least run a Google search for hyrax and Hyracotherium. If they ever bothered they would quickly learn that Hyracotherium was not a hyrax. This is not a judgment call, it is not a debate; it’s a fact.
The skull and teeth of Hyracotherium are significantly different from that of the hyrax as are other details of the anatomy. As they say a picture is worth a thousand words:
Teeth play a big role in paleomammalogy (because they are the hardest part of the skeleton and because of how much they can tell us about an animal), so it is appropriate to compare the dental formula of Hyracotherium and hyraxes to see how similar they might be:
3 . 1 . 4 . 3
3 . 1 . 4 . 3
1 . 0 . 4 . 3
2 . 0 . 4 . 3
For the uninitiated the numbers in the formulas above represent the numbers of different types of teeth on one side of the upper (top numbers) and lower (bottom numbers) jaws. So in the case of Hyracotherium on one side of the upper jaw they had 3 incisors, 1 canine (larger in the males), 4 premolars and 3 molars.
Hyraxes on the other hand had 1 incisor (per side) in the upper jaw, 0 canine (apparently they have small canines as juveniles which they lose as they become adults (i.e. deciduous teeth or baby teeth), 4 premolars and 3 molars.
For comparison here is the formula for modern horses:
3 . 1 . 3(4) . 3
3 . 1 . 3. 3
In modern horses only the males usually have canines and some horses have a small fourth premolar (sometimes called a ‘wolf tooth‘) which seems to be an atavism left over from when their ancestors (like Hyracotherium) had 4 premolars.
As you can see no one who actually bothers to compare Hyracotherium with hyraxes could ever confuse the two. This leaves us with only a couple options when it comes to creationists like Dr. Morris who continue to talk as if they are either identical or nearly so. They are either too ignorant to speak intelligently on the subject and too intellectually lazy to educate themselves, or they do know the difference and choose to lie about it.
Willfully ignorant or dishonest, that’s pretty much the only two options in this case.
This false knowledge that creationists have about Hyracotherium being a hyrax might supply us with a possible explanation for Morris’s bizarre statement about Hyracotherium evolving into elephants. You see with the exception of sirenians (manatees & dugongs) hyraxes seem to be the most closely related animals to elephants. Elephants did not evolve from hyraxes; they only share a closer common ancestor with hyraxes than any other mammals (again except sirenians which share an even closer common ancestor with elephants).
So my hypothesis is that in Morris’s mind the ‘thinking’ went something like this:
Hyracotherium = hyraxes, hyraxes are said by biologists to be related to elephants and since evolution always makes things bigger/better (remember this is a creationist ‘thinking’) hyraxes must have evolved into elephants and therefore Hyracotherium evolved into elephants.
Morris: If you took the tiny three-toed ones out of the line-up, then the fossils would fit the creation picture, showing variety within a created kind.
Except that Dr. Morris has given us absolutely no reason to do so and other creationists (see the quote from Cavanaugh et al. above) agree with paleontologists that the fossil horse series, from Hyracotherium to Equus is legitimate. Instead what Dr. Morris has done, yet again, is give us plenty of reason to doubt his credibility when speaking about anything related to zoology or paleontology.
See also my earlier post on this subject: A horse is a horse, unless of course…
Cavanaugh et al. (2003) “Fossil Equidae: A Monobaraminic, Stratomorphic Series” in: Ivey, R.L., editor, Proceedings of the Fifth International Conference on Creationism, Creation Science Fellowship, Pittsburgh, pp. 143-153
Forey, Peter L. (1998) History of the Coelacanth Fishes
Hulbert, Richard (2004) “The Last Decade (More or Less) of Equid Paleobiology”, Florida Fossil Horse Newsletter 13(2)
Matthew, W. D. (1926) “The Evolution of the Horse: A Record and Its Interpretation”, The Quarterly Review of Biology, 1(2):139-185
Morris, John (2008) “The Mythical Horse Series“, Acts & Facts. 37(9):13
Owen, Richard (1841) “Description of the Fossil Remains of a Mammal (Hyracotherium leporinum) and of a Bird (Lithornis vulturinus) from the London Clay.” Transactions of the Geological Society of London, Series 2, VI: 203-208, 1 plate
Owen, Richard (1848) “Description of Teeth and portions of Jaws of two extinct Anthracotheroid Quadrupeds (Hyopotamus vectianus and Hyop. bovinus)…”, The Quarterly Journal of the Geological Society of London 4(1):103-141
Rose, Kenneth David & Archibald, J. David (2005) The Rise of Placental Mammals: Origins and Relationships of the Major Extant Clades, p. 206