Creationist horse feathers

If creationists keep spewing nonsense about horses and horse evolution, there may come a day when I run out of literary references and idioms involving horses to play off of in my post titles. But today is not that day.

Before I start I want to promise any regular readers of this blog that despite this being yet another post that is (in part) about creationists and horses, I promise there will be no mention of Hyracotherium this time. No quotes of Richard Owen. No references to hyraxes whatsoever, you have my word.

Once again the source of my ire is the Institute for Creation Research (ICR) who sent forth one of their minions, Christine Dao, to dutifully report what the institute’s “creation scientists” had to say about the recent news that the South Korea is going to be altering their school textbooks to pander to creationists in that country.

Dao: Science gained a victory when South Korea’s Ministry of Education, Science and Technology announced last month that textbook publishers will correct editions that contain misinformation regarding evolution.

Yes, absolutely, if there is misinformation in the textbooks we would certainly want to weed that out. The problem is, to a creationist, any of the data that makes up the mountain of empirical evidence supporting evolutionary theory is “misinformation”. Let us examine the two examples of supposed misinformation the South Korean “Ministry of Education, Science and Technology” is planning of removing from textbooks and the “scientific” reasons why the ICR agrees that they should be removed; starting in reverses order with “feathers” (figuratively speaking):

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“Gill slits” by any other name…

Charles Darwin once said that he thought the evidence from the comparative anatomy of embryos was “by far the strongest single class of facts” in favor of common descent (Darwin, 1860) and while it has since been eclipsed by genetics, it remains one of most compelling subsets of evidence for evolution. And perhaps the single most striking detail in the comparative embryology of vertebrates, are the structures colloquially known as “gill slits”.  

Embryonic “gill slits” or “branchial clefts” (branchia is Greek for gill) or more properly pharyngeal clefts (grooves, folds, etc.) are part of what is called the “pharyngeal apparatus” found in front (ventral) and sides (lateral) of the head/neck region of all vertebrates in the “pharyngula stage” of development. In “fish”, and the larva of amphibians, these develop into respiratory organs used to extract oxygen from water while in amniotes (“reptiles”, birds and mammals) they are modified into other structures.

Before I go on, a brief digression about “fish”. Throughout this article I will often use “fish” in the generic sense; but it should be noted that the term as it is commonly used—to refer to any vertebrate that swims in the water, has fins and gills—is not a valid scientific classification. This is because the three main types of animals commonly called “fish” —the Chondrichthyes (sharks, rays, skates and chimaeras), the Actinopterygii (ray fined fish, which constitutes the majority of living fishes), and the Sarcopterygii (lobe fined fish, the group from which four legged land animals, i.e. tetrapods, evolved)—are not a monophyletic group. That is they are not very closely related to each other despite some of their outward similarities (like gills). For example the living Sarcopterygii, lung fish and coelacanths share a more recent common ancestor with us (and all tetrapods) than with the other “fishes”.

OK, so the “pharyngeal apparatus” consists of a series of paired pharyngeal arches and fissures which develop on the exterior with a corresponding set of pharyngeal pouches on the inside of the throat, separated from the external fissures by a thin membrane (more on the details in a moment). And in fact the possession of these structures at some point in development, along with a hollow dorsal nerve cord, a notochord and a post anal tail, are the defining characteristics of the phylum chordata to which we and all other vertebrates belong.

Copyright © 1999 McGraw-Hill Companies, Inc.

Please note that the above illustration is diagrammatic and not intended to be photographically accurate (I have to say that lest I be accused by creationists of conveying a fraud). Below are actual photographs of both a skate embryo and a human embryo for comparison. Also note: the gill structures in the embryos of Elasmobranch fishes—the subdivision of Chondrichthyes which contains sharks, rays and skates—are much less derived than in other “fishes” and therefore generally more similar to those of amniote embryos than the corresponding structures in the bony “fishes” (which are significantly modified).

(Gillis et al 2009, p.5721)

The first of the arches, the mandibular arch, forms the jaw in all jawed vertebrates (Gnathostomes). Most vertebrates develop a total of six arches but the full complement is usually only retained into adulthood by hexanchiform sharks. Hexanchiformes are very plesiomorphic which means that they are more like earlier types of sharks.  Some species of hexanchiformes even develop a seventh arch. Likewise the extant jaw-less vertebrate, the lamprey, also have seven gill openings.

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Open mouth, insert hoof

Ken Ham, president/CEO of Answers in Genesis (USA), which is headquartered in Kentucky has attacked an exhibit at the Kentucky Horse Park on horse evolution in a recent post to his blog “Around the World with Ken Ham” and it is yet another glittering example of creationist scholarship.

Reading it immediately brought to mind the words supposedly* whispered by Thomas Huxley as he rose to respond to Samuel Wilberforce in their exchange at the 1860 Oxford evolution debate:

“The Lord hath delivered him into mine hands”.

The reason this came to mind was that it is clear from his comments that he has not bothered to educate himself on the subject and is just mindlessly repeating tired, long refuted creationist clichés on the subject of horse evolution.  In other words, he’s lobbing softballs at defenders of science like me.

Alright, without further ado let’s saddle up and ride forth into the mind of Ham:

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Creationists are just buggy about bugs

A few months back Frank Sherwin,  “Senior Science Lecturer” at the Institute for Creation Research, launched an amusing attack on evolution that is nigh on word-salad; this time focusing on insects, and how they are supposedly problematic for evolutionary theory.

As usual it is stated with the confidence and the faux authority that is typical of “creation science” practitioners but when you actually look at it and try to make sense of what is being said it quickly becomes apparent that much of it is really unintelligible nonsense.

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Hyracotherium misinformation at scientificamerican.com

I am going to give another wag of the finger, this time to Scientific American. They posted a number of paintings of reconstructions of various extinct “horses” in a picture gallery titled “Ancient Miniature Horses”, which includes an entry for the famous “dawn horse”, Hyracotherium.

However, the problems lies not in the painting, which is probably a reasonable guesstimate of what Hyracotherium might have looked like in life but rather with the blurb of information included with the painting:

Hyracotherium This genus of small early horse roamed the early woodlands of Asia, Europe and North America some 55 million to 45 million years ago. It was already larger than Sifrhippus, weighing about 22.7 kilograms. But when Richard Owen first discovered Hyracotherium in 1876, it was so diminutive that he thought it was some unknown hyrax species, a group of extant mammals that live in Africa and the Middle East. 

Painting by Heinrich Harder used by S.A.

No, no, no, a thousand times no! It is bad enough when creationists claim that Hyracotherium is merely a hyrax (rather than a ancestral horse) and claim that Richard Owen thought so as well but to have a venerable science publication like Scientific American falling into the same pit of misinformation is extremely vexing.

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There’s something fishy about that fish

Institute for Creation Research President Dr. John Morris has taken to recycling; in this case he’s dusted off some nonsense from an article he wrote 3 years ago titled “Evolution’s Biggest Hurdles” (Morris 2008) and repackaged it as “The Biggest Problems for Evolution” (Morris 2011).

As I usually do I started out writing a point by point re-rebuttal to Morris’s new article; even though I already wrote a fairly extensive rebuttal to the earlier version. However, as I was writing, and as it got longer and longer, I realized that I was going to bury the lead way too deep. So, I am dropping most of the rehashing and jump to the new issues I want to address.

First though just a little of the lead in for context:

Morris: Even though the gaps in the fossil record are found between each basic animal type, there are two huge gaps in particular that should be emphasized. The evolutionary distance between single-cell organisms and the vast array of multicellular, highly complex marine invertebrates precludes even rapid evolution.

Oh boy, this is déjà vu all over again.

From earlier context (see below) the “rapid evolution” he is referring to here is supposed to be punctuated equilibrium, however P.E. about apparent, geologically, “rapid” transitions (say a few tens of thousands of years) and concerns species level transitions (like those necessary to evolve horses and zebras from a common ancestor) not multicellular organisms from unicellular ones. Again, I’ll have more on his use of P.E. below.

As for the gap between unicellular and multicellular organisms the (really) short answer is: choanoflagellates (colony forming single celled organisms that are strikingly similar to cells found in sponges called choanocytes). Again, see my earlier post You can tune a piano but you can’t tunicate” for more.

Morris In the supposedly 600-million-year-old layers of rock designated as Cambrian (which contain the first appearance of varied multi-cell life), sponges, clams, trilobites, starfish, etc., are found without the required evolutionary ancestors.

Wrong, wrong, wrong. I covered this before as well.

1) There are fossils of multicellular organism in Precambrian strata (the Ediacaran biota for example).

2) Amongst those Precambrian multicellular organisms are sponges and jellyfish.

3) “Clams” (bivalve mollusks) are known from the Cambrian but only from few tiny extinct types.

4) Starfish or sea stars (Class Asteroidea) fossils do not appear in the fossil record until the Ordovician.

Morris: The gap from marine invertebrates to the vertebrate fish is likewise immense.

Again, Dr. Morris doesn’t want you to know about invertebrate chordates or the evidence for a relationship between chordates and echinoderms. I’ll have more on this in a few moments.

OK, now we get to it:

Morris:  To make matters worse for the evolutionists, fish fossils are also found in Cambrian strata.

If we define the colloquial term “fish” in the usual way (in reference to all aquatic, gill bearing, vertebrates) then yes, a few genera of “fish fossils” have indeed been found in Cambrian strata.

However the word “fish”, is not a scientific term, so the question must be; exactly what sort of “fish” has been found in the Cambrian strata? Dr. Morris does not grace his readers with any further comment on this question; there is however a prominent illustration of a fossil fish that accompanies the article. Here is a screen shot of the page the article appears on:

And here is a larger version of the fish fossil picture:

I think it is fair to say that most people who are not particularly familiar with vertebrate phylogeny and paleontology—including most of Dr. Morris’s readers—might assume when they read in his article that “fish fossils are also found in Cambrian strata” that the large centrally displayed picture of a fossil fish might in fact be one of the Cambrian fish Morris is referring to.

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A Tale of Two Dinosaurs

The Institute for Creation Research has graced us once again with a brilliant display of their scientific prowess. This time the focus of their efforts revolves around the recently published description of a newly unearthed dinosaur species Eodromaeus murphi.

Eodromaeus is a small (slightly over a meter in length) South American dinosaur from the mid-Triassic (230 MYA). This date makes it one of the earliest dinosaurs and its describers, Ricardo Martinez et al., argue that it should be classified as a basal theropod ―the carnivorous branch of the “lizard-hipped” or saurischian dinosaurs (Martinez et al., 2011).

What has ICR’s, or more specifically ICR “science writer” Brian Thomas‘ knickers in a twist is that in the same paper in which they describe Eodromaeus the authors also argue for the reclassification of another dinosaur, Eoraptor (described back in the early 1990’s), which is from the same location and roughly the same time period as Eodromaeus.

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