Monday, March 13, 2017

Learning more

Tully Monster

Sometimes creationists criticize theistic evolutionists because merging theology and the science of the day is always dependent on what exactly the science of the day is. Historically, we know that science changes. We know there are big "paradigm shifts" that change our perspective on every part of a field, even though such shifts are rare. Modifying theology in light of the changing landscape of science seems like a poor idea, especially if you want to mess around with more important issues of Christian theology. Perhaps it's best to leave the theology alone, and wait to see if the science modifies itself.

Unfortunately, what I think is a legitimate point about the nature of science often comes across quite badly.  I've heard creationists sneering at reports of scientists changing their minds. I've heard creationists laughing at such reports and saying, "Scientists really don't know anything!" Others have exclaimed, "It's all just speculation!" I've heard speakers basically imply that science is unreliable and can't be trust at all. I certainly get the sense from some of these folks that they really are anti-science.

We really need to be careful how we phrase this argument. On the one hand, modifying major points of theology in light of the science of the day is not necessarily a good plan, but that doesn't mean science is bogus. What we should be saying is that perhaps we should let the science work itself out, because that's what science does. Scientists learn new things, and they modify what they thought they "knew" about the world in light of new knowledge. Science values discovery. We love learning new things.

Besides all that, casting aspersion on science cuts both ways. How can we credibly present scientific research that supports a young-age creationist position and then turn around and disparage science? That's just shooting ourselves in the foot.

With that said, let's learn some new things. Back in 2014, I was very excited to read reports of the discovery of the weird critter Dendrogramma:
...these peculiar creatures were dredged from the ocean bottom off Tasmania in 1986.  They are definitely animals, but they don't look like anything previously known to science.  The authors classified their discoveries in a new family Dendrogrammatidae, but they declined to go any farther.  The specimens are probably a whole new phylum of animals, but we don't know for sure.  They could be really, really weird-looking worms or jellyfish or something like that.  Having DNA sequences would help clear that up, but the samples were treated with formalin, which makes recovering DNA difficult.
Last year, there was a less heralded report in Current Biology written by O'Hara and colleagues identifying Dendrogramma. Their research team found additional specimens of Dendrogramma, from which they could isolate DNA sequences. Although these critters are very weird looking, they are not so exotic after all. Turns out they're in the jellyfish phylum Cnidaria, and specifically in a family called Rhodaliidae. So Dendrogramma is a really odd-looking jellyfish-type critter instead of a new phylum altogether.

More recently, I blogged about the strange fossil Tully monster (above) being identified as a vertebrate. I wrote,
These critters are really strange, with eyes mounted on stalks and a mouth at the end of a long, narrow snout.  What could this thing possibly be? McCoy and colleagues published a research paper this year that described a detailed examination of 1,200 different fossils of Tully monsters.  They concluded that, believe it or not, the Tully monster is a kind of vertebrate, possibly similar to lampreys.  This research won't end the discussion of this strange creature, but McCoy's paper will remain a standard reference on Tully monsters.
It turns out that I was right. That paper not only didn't end the discussion about Tully monsters, it spawned a completely new discussion of fossil preservation. In a recent paper in the journal Palaeontology, Sallan and colleagues argue that the features used to identify the Tully monster as a vertebrate were misidentified. They note that some vertebrate characteristics not found in Tully monsters should be more surprising if Tully monsters were vertebrates, because other vertebrates from the same fossil deposit do preserve those characteristics. Once again, I'm sure we haven't heard the last of the Tully monster.

Should we conclude from these studies that scientists are clueless? Quite the contrary, the self-correcting nature of science is a valuable thing. These studies help us understand how further research is important. Nothing in science is unquestionable. We can always learn new things. And that goes for creation research, too. Who knows what the next discovery will bring?

O'Hara et al. 2016. Dendrogramma is a siphonophore. Current Biology 26:R457–R458.

Sallan et al. 2017. The ‘Tully Monster’ is not a vertebrate: characters, convergence and taphonomy in Palaeozoic problematic animals. Palaeontology DOI 10.1111/pala.12282.

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