Defining Dinosauria

Richard Owen poses next to a Dinornis (moa) skeleton in 1879—but is it a dinosaur?

This group, which includes at least three well-established genera of Saurians, is characterized by a large sacrum composed of five anchylosed vertebrae of unusual construction, by the height and breadth and outward sculpturing of the neutral arch of the dorsal vertebrae, but the twofold articulation of the ribs to the vertebrae, viz. at the anterior part of the spine by a head and tubercle, and along the rest of the trunk by a tubercle attached to the transverse process only; by broad and sometimes complicated coracoids and long and slender clavicles, whereby Crocodilian characters of the vertebral organs also exhibit the same transitional or annectent characters in a greater or less degree. The bones of the extremities are of large proportional size, for Saurians; they are provided with large medullary cavities, and with well developed and unusual processes, and are terminated by metacarpal, metatarsal and phalangeal bones, which, with the exception of the ungual phalanges, more or less resemble those of the heavy pachydermal Mammals, and attest, with the hollow long-bones, the terrestrial habits of the species.

That’s how, in 1842, Richard Owen described “a distinct tribe or sub-order of Saurian Reptiles, for which I would propose the name of Dinosauria“, a group of organisms which needs no further introduction. But what, 170 years later, can be properly classified as a dinosaur? Former highschool science teacher Brian Thomas thinks he knows better than today’s scientists. He wrote on Wednesday, in “Four-Winged Dinosaur Definition Doesn’t Fly“:

Confounding the Patriarchs

In late 2013, as a response to an article by Brian Thomas rounding up what he considered the ICR’s greatest hits of the year, I wrote a post consisting of historical quotes altered to support each creationist claim Thomas brought up. For example – pertaining to the usual comet trope – Confucius almost certainly never said:

Heaven, in the production of things, is sure to be bountiful to them, according to their qualities. Hence the comet that is flourishing must be replaced often, as the bulbs don’t last like they used to.

Hardly the pinnacle of comedy, I know, but I never claimed to be any good. I mention this old post not to revisit past failures but to bring attention to the underlying point of this bastardisation of Marcus Aurelius:

He who has seen present things has seen all, both everything which has taken place from all eternity and everything which will be for time without end; for all things decay predictably and exponentially (except isotopes).

Anyone who has been reading creationist arguments for very long has probably noticed this for themselves: while YECs vehemently deny that radioactive isotopes decay in a predictable and inalterable fashion that could be used to accurately determine the passage of time, they themselves often contend that other processes decay in the same way. Humphreys’ ideas about planetary magnetic fields might be the example that most commonly appears here, but today Brian Thomas provides us with a new one. He writes, in “Did Adam Really Live 930 Years?“:

Disappearing Genes

We’re not actually talking about four-leaf clovers today.

Gah, some real writers block on this one. Sometimes I get halfway through a post and I know what I want to say, but I can’t wrestle it into my usual style. It tends to happen when the topic is generally fairly boring, yet at the same time intensely interesting to me personally in a way that I can’t show to anyone else. I want to go down all kinds of rabbit holes, but this isn’t terrible conducive to producing a coherent and informative blog post. So I’ve stopped writing and opened a text document, and I’m going to try give you a tour of the more interesting bits.

First: the Brian Thomas article is “Clever Clover: Evidence for Evolution?“; the paper is “Adaptive gains through repeated gene loss: parallel evolution of cyanogenesis polymorphisms in the genus Trifolium (Fabaceae),” (press release, pdf). Some clover plants produce cyanide, some don’t, the pattern isn’t what you might expect – you see both forms in the same species, and the versions that lack cyanide (having it is the default) seem to have evolved independently via the same pattern of gene deletion. You get the idea, I hope.

We Don’t Know Everything About Electric Fish

There are six different lineages of so-called “electric fish,” each of which evolved its potential independently and convergently. The most famous of these is the electric eel, though speaking of convergent evolution that species is not actually an eel. The portion of the body that produces the electric field is called the “electric organ,” and appears to be derived from muscle cells, but are quite different from each other. A recent paper in Science – “Genomic basis for the convergent evolution of electric organs” (pdf, press release) – investigating representatives of four of six lineages determined that, despite their differences, the same underlying genetic and cellular processes have been leveraged (or hijacked) in each case.

Nathaniel Jeanson has an article up today about this paper called “Darwin’s ‘Special Difficulty’ Solved?” His conclusion is, if anything, unusually weak, and it’s difficult to know what to make of it. He begins by quote-mining Darwin, a common tactic but one which the ICR doesn’t seem to often resort:

Crooked Dealer at Sima de los Huesos

A fossil from Sima de los Huesos.

While other groups of young-Earth creationists may hold differing opinions, the Institute for Creation Research insists that Neanderthals were humans too. This is all very well, but for reasons that are not at all clear they take this position to the extreme, minimising, misreporting, or denying any genetic and morphological evidence of differences between modern humans and their former contemporaries, and trampling over the more nuanced scientific view that Neanderthals were very closely related to us yet also a distinct group. Today Brian Thomas writes “Human Remains in Spain: Neandertal or Not?“, going so far that he ties himself up in knots.

A paper in Science – “Neandertal roots: Cranial and chronological evidence from Sima de los Huesos” (pdf), published on the 20th of June – investigated the accretion model of Neanderthal origins. The cliffs notes on this idea seems to be that the notable Neanderthal-specific features appeared at different times in a stepwise fashion, with those associated with the jaw for example developing before those related to the brain. The skeletons at the Sima de los Huesos cave in Spain, being around 430,000 years old according to this paper, lie in the middle of this transition and so provide a test case (who said you couldn’t test things in “historical science”?). The authors looked at the bones of 17 individuals and did indeed find Neanderthal faces with more archaic brains. They write:

Tomkins’ 70%

Because mammalian eggs are produced early in life, while sperm are created continuously, fathers are responsible for a greater share of new mutations passed down to their offspring than mothers. This slightly complicates genetics-based time-since-last-common-ancestor estimations, leading to recent results to the effect that the human-chimp split happened about twice as far back as previously thought. Adam Benton has more information, if you’re interested.

This new paper has prompted Jeffrey Tomkins, the ICR’s go-to geneticist, to publish “Chimp DNA Mutation Study–Selective Yet Surprising.” Tomkins is known for contesting the typically-cited genetic similarity figures of 94-99% and having calculated using his own method a “conservative” (i.e. maximum) figure of nearer 70%.

The Case of the Missing Polyploidy

Osmunda regalis, a royal fern.

For Wednesday 16 April Brian Thomas writes: “Fossil Plant Chromosomes Look Modern.”

An 180 million year-old royal fern fossil has been discovered in Sweden that is so stunningly preserved that it still shows the components of individual cells. The nucleus – and even the nucleolus – can be easily seen, and cells that appear to be in the process of division show their chromosomes. The paper, “Fossilized Nuclei and Chromosomes Reveal 180 Million Years of Genomic Stasis in Royal Ferns,” in Science, is unfortunately closed access, but phys.org has pictures. The preservation is good enough, in fact, that the researchers report that they’re basically the same as in living royal ferns. The “living fossil” creationist argument is probably well familiar to you, so the content of Thomas’ article shouldn’t be all that surprising.

Dismissing Inflation

On rare occasion the ICR manages to publish articles on recent news items in an approximately timely manner. Today’s DpSU, “‘Smoking Gun’ Evidence of Inflation?” by Jake Hebert, is one example, attempting to counter the rather inconvenient announcement of evidence supporting the cosmological hypothesis known as inflation.

While quicker than is typical for the ICR, Hebert is by no means the first to comment on this issue. Discovery Institute cdesign proponentsist Stephen Meyer was quoted as saying that

…it’s really odd for people from a Creationist perspective to deny a theory that says the universe began out of nothing physical.

Naturally, many of his fellow creationists have a decidedly different view.

The Tiny Tranquil Flood

Callan Bentley is an American geologist who runs the blog known as Mountain Beltway on the American Geophysical Union’s network. If, for some strange reason, you don’t follow him there you may well at least know of him as the scientist who pointedly refused the use of one of his photos in the Discovery Institute’s book Darwin’s Doubt.*

At some point in February he and Alan Pitts were apparently looking at sediment exposed by a some road cuts in the Appalachian mountains. Specifically they were looking at what they thought was the Hampshire Formation, which is supposed to be terrestrial in origin (i.e. rivers rather than oceans). But within the outcrop they found a few metres of black marine sediment, containing bands of limestone and a variety of fossils. Bentley wrote:

Doing the Planetary Freestyle

That break lasted longer than I thought, but less than I feared. Longtime readers will have noticed that posting tends to slow or vanish entirely around this time of year due to the start of school: it’s only the second week of university now,* which isn’t so bad. It’s also the start of US daylight saving time this week, which helpfully brings typical ICR posting time to a slightly more manageable hour.

Nothing has visibly changed in Dallas in my absence. Today’s Creation Science Update is by Brian Thomas, and called “Asteroid Medley Challenges Naturalistic Origins.” I’ll admit that I had to look that word up to see whether it has a meaning beyond the realm of competitive swimming, but it seems so.