Abominable mysteries

One of the most annoying things I run across regularly is when someone takes a perfectly good piece of scientific research and twists it to support their own highly unscientific pre-existing beliefs.

The latest in this long parade of frustration I found out about because of my good friend, the amazing writer Gil Miller, who is a frequent contributor of topics for Skeptophilia.  Gil sent me a link to a fascinating paper that came out a month and a half ago in Nature about one of the most perplexing puzzles in evolutionary biology -- the sudden diversification of flowering plants during the Cretaceous Period, something on the order of 150 million years ago.  They went on to outcompete every other plant group, now comprising ninety percent of the known plant species, totaling about 13,600 different genera.  If you look around you, chances are any plant you happen to see that isn't a moss, fern, or conifer is a flowering plant.

What caused their explosive rise and diversification, however, is still unknown.  Their success might well be due to coevolution with pollinators, especially insects, which had a sudden spike in diversity around the same time, but that's speculation.  The current study vastly expands the genetic data we have on current genera of flowering plants, rearranging a few groups and solidifying what we know about the branch points of different clades within the group.  However, it still doesn't solve the reason behind what Darwin called "the abominable mystery" of why it all happened -- something the authors are completely up front about.

[Angiosperm phylogenetic chart from Zuntini et al., Nature, April 2024]

Well, any time an evolutionary biologist says "we don't yet understand this" -- especially if it's something Darwin himself noted as odd or mysterious -- it's enough to get all the anti-evolution types leaping about making excited little squeaking noises, and it didn't take long for this paper to appear in an article over at Evolution News (don't let the name fool you; the site is sponsored by the staunchly creationist Discovery Institute).  The article (so I can save you the trouble of clicking the link and adding to their hit rate) glosses over all of the stuff Zuntini et al. did explain, and highlights instead the fact that they never accounted for the reason behind flowering plant diversification (which wasn't even the purpose of the study).  The article ends with, "Nature clearly did make jumps in the history of life and this cannot be explained with an unguided gradual accumulation of small changes over long periods of time, but requires a rapid burst of biological novelty that is best explained by intelligent design."

Basically, what we have here is yet another iteration of the God-of-the-gaps argument; "we don't yet understand it, so musta been that God did it."  The problem is, you can't base a conclusion on a lack of data.  For the intelligent design argument to work, you'd have to show that it explains the data better than other models do.  Simply saying "we don't know, therefore God" isn't actually an explanation of anything, something that atheist philosopher Jeffrey Jay Lowder brought into sharp focus:

The objection I have in mind is this: the design hypothesis is not an explanation because, well, it doesn’t explain. ...  [I]t seems to me that a design explanation must also include a description of the mechanism used by the designer to design and build the thing.  In other words, in order for design to explain something, we have to know how the designer designed it.  If we don’t know or even have a clue about how the designer did it, then we don’t have a design explanation.

Which is it exactly.  Science works because it not only self-corrects, it holds explaining things in abeyance until there's enough data there to warrant a robust explanation.  A mystery is just a mystery; maybe we'll figure it out at some point and maybe we won't, but until then, it doesn't prove anything.  Science doesn't simply look at a lack of information and then throw its hands in the air and say, "Well, must be X, then."

To quote eminent astrophysicist Neil deGrasse Tyson, "If you don't know what it is, that's where the conversation stops.  You don't go on and say it 'must be' anything."

Honestly, it's astonishing that the creationist types are still using the God-of-the-gaps approach, because the truth is, it's more damaging to their position than it is helpful.  The reason was noted by German theologian Dietrich Bonhoeffer: "[I]t is [wrong] to use God as a stopgap for the incompleteness of our knowledge.  If in fact the frontiers of knowledge are being pushed further and further back (and that is bound to be the case), then God is being pushed back with them, and is therefore continually in retreat."

But that line of reasoning -- from a respected theologian, no less -- doesn't seem to be slowing them down any.

So I'll apologize to Zuntini et al. on behalf of the entire human race for these unscientific yayhoos taking a really lovely piece of research and claiming it supports their beliefs.  The tl;dr summary of this post is: it doesn't.  At all.  At worst, the study indicates that there's still stuff we don't understand, which is a damn good thing because otherwise the scientists would be out of a job.

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Science shorts

Today, I want to look at some awesome shorts that were too good to pass up.

No, not that kind.

In the last couple of days I found three recent bits of research that are just plain cool, and I couldn't resist sharing them with you.

First, we have a new discovery out of China showing that flowering plants were around a great deal earlier than we'd thought -- the early Jurassic Period, 174 million years ago.  This pushes back the earliest evidence of flowering plants by a good fifty million years!

Called Nanjinganthus dendrostyla, this little flower grew during a time when we'd thought there was nothing much around, botanically speaking, but gymnosperms (relatives of today's spruces, firs, and pines), ferns, and other more primitive plants.  But a fantastically well-preserved group of fossils has shown that they shared the space with some of the earliest angiosperms, or flowering plants.

One of the Nanjinganthus dendrostyla fossils 

After careful microscopic analysis of the flower, the researchers put it together like this:

So cool, even if it's not something you'd necessarily want as the centerpiece of your garden.

The significance of the discovery goes beyond its age.  There are some other features that bear mention, as is described over at the blog In Defense of Plants (linked above):

Another surprising feature is the presence of an inferior ovary that, by its very definition, sits below the sepals and petals.  It has long been hypothesized that early angiosperms would exhibit superior ovaries so this discovery means that we must rethink our expectations of how flowers evolved.  For instance, it suggests we may not be able to make broad inferences on the past based on what we see in extant angiosperm lineages.  It could also suggest that the origin of flowering plants was not a single event but rather a series of individual occurrences.  It could also be the case that the origin of flowering plants occurred much earlier than the Jurassic and that Nanjinganthus represents one of many derived forms.  Only further study and more fossils can help us answer such questions.

The second story comes from zoology, and it concerns eyeless cave fish -- fish whose ancestors were trapped in dark caves, and evolved to lose their visual sense.  There's a fundamental misunderstanding that a lot of people have about these species, usually centering around the Lamarckian view that the fish lost their eyes "because they didn't need them any more."  The actual truth of the matter seems to be that if you're in perpetual darkness, using a lot of your energy to produce and maintain a structure as complex and delicate as the eye would be a waste, and diverting those resources to other, more useful purposes is a significant advantage.  It's a subtle point, but an important one.

In any case, this current research turns on two questions -- how cave fish navigate their habitat, and why they have asymmetrical faces -- a curiosity that they share with blind cave crickets.

It turns out that the two questions are related.  The convex side of the fish's skull contains more neuromasts, organs that are not only tactile sensors but give fish information about vibrations and water speed and direction.  All fish have these, but blind fish rely on them to create a mental map of their habitat.  Researchers found that most of the fish have skulls that bend slightly to the left, meaning they're getting tactile input mostly from the right.  And just as you expect, the fish whose skull bends to the left keep their right side in close contact to the walls, and tend to move counterclockwise around their habitat -- and the right-bending fish move the opposite way!

The whole thing brings to mind an article that appeared many years ago in the inimitable science spoof The Journal of Irreproducible Results, describing a little mammal called the Sidehill Gouger that has two short legs on one side and two long legs on the other, so it can stand upright on hillsides.  Thus, like our cave fish, some Sidehill Gougers always travel clockwise, and others counterclockwise.  The article goes into the genetics of the trait, describing how the offspring of a right and a left-handed Gouger produces some of each, but heterozygous individuals end up with diagonally opposite short legs.

They're called "Rockers."

I doubt there's any analog in the cave fish, but it's interesting and more than a little ironic that a piece from JIR actually ended up within hailing distance of reality.


The last story puts to rest the idea that scientists don't know how to have fun.  A couple of mechanical engineers from Boston University, Alexandros Oratis and James Bird, published some research this week in Physical Review Letters describing the physics of shooting a rubber band -- and how to optimize your strategy so it goes straight and doesn't smack your thumb on the way out.

After filming rubber band shooting with an ultra-high-speed camera, what Oratis and Bird found was that when it comes to tension, less is more.  When the rubber band is released, the release of tension in the band zooms forward, and the back end of the band follows, but at a slower speed.  When the tension release reaches your thumb, it allows your thumb to snap forward, dodging the band as it passes.  If you pull too hard, the speed of the tension release is higher, and it's simply too fast for your thumb to duck out of the way.  The result: you give yourself a nice stinging smack.

Wider rubber bands also work better, and for a similar reason; they have a higher tension, so when that's released, your thumb jerks forward more quickly.

Me, I wonder how many times Oratis and Bird popped each other with rubber bands while doing this research.


So there you have it.  Rubber band war strategy, lopsided cave fish, and extremely early flowers.  All of which illustrate what I've claimed all along: science is fun.

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Carl Zimmer has been a science writer for a long time, and his contributions -- mostly on the topic of evolution -- have been featured in National Geographic, Discover, and The New York Times, not to mention appearances on Fresh Air, This American Life, and Radiolab.  He's the author of this week's Skeptophilia book recommendation, which is about the connections between genetics, behavior, and human evolution -- She Has Her Mother's Laugh: The Powers, Perversions, and Potentials of Heredity.

Zimmer's lucid, eloquent style makes this book accessible to the layperson, and he not only looks at the science of genetics but its impact on society -- such as our current infatuation with personal DNA tests such as the ones offered by 23 & Me and Ancestry.  It's a brilliant read, and one in which you'll learn not only about our deep connection to our ancestry, but where humanity might be headed.

[If you purchase the book from Amazon using the image/link below, part of the proceeds goes to supporting Skeptophilia!]