Natural Selection in the Meadow of Science

Imagine a meadow full of flowers. Imagine yourself as a bee, looking for flowers that have the nectar that you want to eat. Which ones will you go to? There are only so many hours in the day, and you have to make the best use of your time in the sun. You may choose the biggest and brightest flowers, if for no other reason than that they grabbed your attention.

Natural selection results. The bees choose the biggest and brightest flowers, and these are the ones that get pollinated and produce a lot of seeds. In addition to natural selection, there is also sexual selection. The big, colorful flowers attract pollinators to bring, and to take away, pollen, which is the male function of the flower. I am unclear on the concept of how a pollinator can enhance a flower’s male success without also enhancing its female success, but the scholarly articles about pollination customarily make this distinction.

Now imagine that the meadow is full of graduate students looking for jobs in academia. They want their scholarly articles not to just get published but to get noticed. How can a graduate student do this?

Of course, the article has to be well written and technically accurate. An inaccurate article is as counter-productive as a flower that, due to a genetic or developmental defect, cannot produce seeds.

And this used to be all that mattered. Scientific articles had to be correct, not necessarily interesting. As a matter of fact, old scientific articles seemed to me to compete with one another to see how boring they could be.

But now, scholarly articles have to catch the reader’s attention.

I think this is a positive development. Like many other professors, I am overwhelmed with work. I do not have time to read a bunch of scientific articles. All I can do is to visit the websites of the professional organizations to which I belong (for example, the Botanical Society of America), click on each monthly issue of the journal (American Journal of Botany, AJB), and scroll through the titles. If one catches my attention, I click on it. Right at the top, under the title and names of authors, is a summary, called an abstract. It might be one or two hundred words long. And that is usually all I have time to read. If I want to look at it again, I highlight and copy the title and put it in a digital file to which I can refer later. Even this I mostly do on vacation.

You can see how important it is to have a clear and interesting title. The title might be all that most members of the Society read. Sometimes, the titles sound more like something from National Geographic than from AJB. (I repeat, this is a good thing.) Here are some examples, from 2017 and 2018:

• There was an article about the beautiful red-spotted golden flowers of Mimulus guttatus. I have long admired this flower, and was surprised to learn that in addition to being beautiful it had a nifty trick. The stigma (the surface on which pollinators deposit the pollen) closes itself up when it is touched. This is valuable for flowers that require pollen from a different flower. The ones that pollinate themselves, however, have lost the ability to close up their stigmas. The title began, “Losing one’s touch.”
• Plant species related to Amsinckia, which produces flowers on a stalk that unfurls like the neck of a violin, are found in both North and South America. Genetic analysis has revealed that seeds of these plants journeyed from one hemisphere to the other 18 times. Interesting, but I might have missed it were it not for the first part of the title: “Memoirs of a frequent flier.”
• There was an article about parasites seeking host vines. But these vines might be hard to find, interspersed with many other plants on which the parasites cannot live. The title began, “Reading between the vines.”
• There was a series of articles about the computer-based analyses of plant evolutionary history. One was about the plant family Campanulaceae (bellflowers). The title began, “Can we build it? Yes, we can, but should we use it?” The title of another article, about the plant family Apocynaceae (milkweeds), began, “Evolution on the backbone.” The author was referring to the backbone of the phylogenetic tree, not animal backbones.
• The August, 2018 AJB issue focused on how the “tree of life,” which shows the evolutionary relationships of all living species of plants, can be improved by adding in extinct, fossilized species, thus making it “The Tree of Death.” One of the article titles began, “Wanted dead or alive (probably dead).”

Interesting titles are good not just for us scientists, but also for science journalists, who write popular articles for everyday people to read. In case science journalists look over the titles, they will only notice the interesting ones. With a boring title, your research will never get mentioned in popular magazines or websites. One of the world’s leading journals, Science, has popular summaries of its technical articles near the front of each issue. The titles sometimes stretch themselves to the limit to get your attention.

For example, in the August 2, 2019 issue of Science, there is a technical article titled, “Laboratory mice born to wild mice have natural microbiota and model human immune responses.” If you read this title carefully, you can see that it is a pretty exciting article, bringing together two important aspects of modern medicine: microbiota (e.g. in your gut) and immunity. The summary at the front of the journal is titled “Walk on the wildling side,” and the news summary title is “Born to be a wildling.” The news summary titles tell you almost nothing about what the research is about; they exist solely to grab your attention. “Wildling” comes from the title of a 2018 movie.

In the immediately previous issue, there was a technical article about neutral mutations; that is, they are DNA mutations that have no measurable effect on the organism. Geneticists call these mutations cryptic. The title of the technical article is “Cryptic genetic variation accelerates evolution by opening access to diverse adaptive peaks.” The news summary article was entitled “Tales from the crypt(ic).”

Even the technical articles sometimes make a big stretch to gain attention. Several years ago there was a Science article about a Mediterranean volcano. The title began, “Bang!”

This has been going on for a long time, though less than at present. A 2002 article in the journal Oecologia is entitled, “It takes two to tango but three is a tangle: Mutualists and cheaters on the carnivorous plant Roridula.”

But sometimes the titles promise more than they can deliver. One 2017 article in AJB was entitled “Ecological and evolutionary consequences of tri-trophic interactions: Spatial variation and effects of plant density.” The title made me excited. It would make you excited, too, if you are a plant ecologist. It sounded like ecology at its best: biological processes having ripple effects up and down the food chain, that is, three trophic levels. I can almost hear John Muir saying that everything in the universe is hitched to everything else and that he would love to read the article.

But then I looked at the summary of the article. The seeds themselves are the first trophic level; the insects that eat the seeds, the second; and the parasites that eat the insects, the third. But the article simply showed that insects will be more abundant in places where there are more seeds, and that the parasites that afflict the insects are not affected by seed or insect density. The first conclusion was something we have already known for decades; the second conclusion was that the parasites didn’t affect the system. I thought that I was going to learn something new about ecology, in general, and was disappointed. If the authors had entitled the article “Seed predators eat more seeds when there are more seeds, and parasites have no effect on them,” the article would not have been noticed, perhaps not even published. All this, in spite of the fact that there was nothing technically wrong with the article.

If you want a job in the academic world, you have to publish articles with interesting titles (good) and that maybe promise more than they can deliver (not so good). Overall, I am glad that scientific titles are more interesting than they used to be. I certainly made some stretches for the chapter titles in my most recent book. But sometimes, just sometimes, a clever title makes me wonder if the author is hiding something.

The Ascent of Jacob Bronowski

I just finished reading a pre-publication copy of Timothy Sandefur’s upcoming The Ascent of Jacob Bronowski. If even I, a reader of many popular science books, have barely heard of Jacob Bronowski, you can bet that most people have forgotten him. But before there was Neil DeGrasse Tyson, before Stephen Jay Gould, before Carl Sagan, there was Jacob Bronowski (1908-1974) whose passion was to open up the minds of non-scientists to the power and beauty of science.

Bronowski’s work was based on a fundamental assertion of faith that I share, but which I sometimes question. It is that most people are smart enough to understand science, at least in its basic outlines, and smart enough to use the scientific mode of thought. This is the basis of my book, to be released in December, ScientificallyThinking. Bronowski’s gospel was to get scientists to speak clearly and simply to non-scientists and open their eyes to science. I believe that most people are smart enough to do this, but relatively few people really want to. Most people would rather sit in their backwater of ignorance and listen only to things that reinforce their lazy prejudices.

Bronowski (known to his friends as Bruno) was the perfect example of a Renaissance Man, that is, someone who is interested in everything. I first learned this term back about 1977 when a friend called me a Renaissance Man. I was a biology major who wrote novels, wrote orchestra music, and studied history and languages. Perhaps only a Renaissance Man (or woman) can make the connections necessary to bring people from all different modes of thought together. This was certainly Bronowski. An English child of eastern European immigrants, he started off as a poet. But he was also interested in mathematics, which led to statistics. (Statistics differs from pure mathematics because pure math deals with the certainties of deduction, while statistics tries to understand the messy reality of the world through induction. At least, that’s my summary of it.) His mathematical expertise got him involved in the effort for the Allies to win World War II, and later to make industrial production more efficient.

This mathematical work did not always lead Bronowski where he might have expected. Yes, he helped the Allies win World War II, but like many other scientists he was deeply disturbed by the effects of atomic bombs. He traveled in Japan after the bombs, and knew that the new power we had unleashed from the atom was completely disproportionate to any legitimate military goals even the best of countries might have. Also, his dedication to industrial efficiency led him on the ultimately quixotic quest to produce Bronowski Bricks from coal dust, sort of a fossil fuel version of charcoal briquets. The briquets reduced coal waste, to be sure, but they were very expensive to produce, and, according to Prince Philip, they looked like turds.

But Bruno’s wide knowledge, and being at the right place at the right time, threw him into the public spotlight in radio and television broadcasting. He produced, one after another, important science documentaries, culminating in his still-famous The Ascent of Man. He dabbled in lots of things at which he was not really skilled, such as writing a light opera libretto that was not very good (the music was by Peter Racine Fricker, who was on the music faculty when I entered the University of California at Santa Barbara). But he tried!

Science and art, said Bronowski, were both creative. Take, for example, Copernicus, who did some of the earliest work that proved the sun to be the center of the solar system, rather than Earth being the center of the universe. Copernicus had to imagine what the planets would do if he were at a central solar vantage point, but as an artist has to imagine what the final work would look like. Both scientists and artists test concepts: scientists, how well the concept explains the natural world, and poets, how well the poem expands our experience.

Another idea he had was that animals need intelligence in order to have free will. You have to be able to visualize possible futures before you can choose among them. Only humans can do this. I do not know if Bronowski actually solved the problem of free will, but he clarified it, at least for non-philosophers like me. He helped lay the foundation for the study of language acquisition. He said that only humans can make a sentence out of separate words, and then isolate one word and generalize about that one concept.

When he helped to start the Salk Institute, Bronowski moved to La Jolla, California. He would host scholars for discussions in his living room (where he also filed the final episode of Ascent). He was an inspiring partner for dialogue. While he knew everything about everything, he could make you feel brilliant even when he was saying you were wrong, according to more than one of his acquaintances.

Jacob Bronowski inspired us to think big, to see all human thought as a single fabric rather than as a collage of specialties. And he was an early inspiration for what we now call citizen science. They didn’t have the internet back then, but on his televised shows he encouraged viewers to send in postcards with their own scientific thoughts on them.

You can get a taste for the kind of spellbinding quality Bruno had by seeing this short YouTube clip from one of the Ascent episodes. Apparently when the BBC was filming this segment, they did not expect Bruno to walk out into the pond; this was extemporized.

I have a lot of different kinds of creative and intellectual output. I am not equally good at all of them, and am not world-class at any of them, as far as I can tell. But I can still do a lot of good with them. Bruno is my guiding light in this respect.

My Green, Green Happy Place

Sometimes I like to go to my happy place. This time, it was so that I could relax and enjoy my happiness at being a new grandfather. For some people, their happy place is a fantasy inside their minds. But for me, it is an actual place: the forest. In particular, the forest on Turkey Mountain outside of Tulsa.

The forest is a place with layers upon layers of stories. It is a palimpsest, that is, a document with layer upon layer of writing. On this particular like, I already knew almost all of the stories. One story was the geological history of the landscape. As I looked down from the mountain onto the Arkansas River, I remembered that this mile-wide river was once ten miles wide, as the glaciers up north melted. Another story was about human impact. The forest all around me grew in just the last century, since the time when this mountain was covered with oil derricks. Each species of tree, and each tree, had its own story: an evolutionary story of adaptation, and a developmental story of how each individual tree adjusted to its immediate environment of shade and sun, of deep soil or rock outcrop. The story is written from moment to moment. When I hiked, a drought was underway, and many leaves were wilted. Wilting is not completely a bad thing; by drooping down, a leaf has less of a heat load from the sunlight and avoids some of the damage it would otherwise experience. There are also many stories of food webs, whether it is of insects that have eaten the tender leaf tissue between the veins, or fungi eating dead branches. There is the story of the hard, green, inedible persimmon fruits that keep animals away until the seeds are ready to disperse, and only then do the fruits become ripe and delicious. There is the story of stumps sprouting back to life.

I knew all of these stories, but I just wanted to see them again on this hike. But I kept my eyes open, just in case there was a new story. And I found one—just one. A mimosa sampling was hit hard by the drought. Mimosas have lots of little leaflets which, after being held horizontally to face the sunlight in the day, close upward at night for reasons that nobody knows for sure. The leaflets also close upward during moderate drought, thus reducing their solar heat load. The leaflet movements are caused by bags of water called pulvini (singular pulvinus). When the bags of water exert pressure, they push the leaflets; when the bags lose pressure, the leaflets return to their original position.

But what I did not know was, are the pulvini on the top of the leaf or the bottom? If they are on top, then the water pressure pushes the leaflets open; their nocturnal closure represents only a loss of pressure, a relaxation, going to sleep. If this is the case, then the closure of the leaflets at night does not need an explanation. The plant is saving energy by letting the leaves relax. But if the pulvini are on the bottom, then the nocturnal closure demands an explanation: why would the mimosa leaf deliberately close its leaflets at night? This requires the expenditure of energy. The same is true for leaflet closure during moderate drought. If the pulvini are on the top, leaflet closure is merely the result of drought; but if they are on the bottom, then leaflet closure is a deliberate act to prevent drought damage. Of course, the pulvini are too small for me to see.

But I saw one leaf that was so stressed by heat and drought that the leaflets were starting to curl up and die. And in this leaf, the leaflets were horizontal. This tells me that the pulvini are on the bottom. I know this because, when severe drought causes the pulvini to stop working, the leaflets are horizontal, not vertical. In the photo, the drought-damaged leaflets are on top, the leaflets that are actively responding to drought are on the bottom. The damanged leaflets are horizontal, and the responsive leaflets are almost vertical.

To me, this was a new story that I learned on my hike. But I enjoyed re-experiencing the thousand other stories in the forest that I already knew.

There Are a Lot of Scientific Questions a Citizen-scientist Can Answer

To get answers to some of the biggest questions in the world today, we need to have literally millions of data points and analyze them with large computers. The best example is global climate change. In order to say that the Earth is getting warmer, we must have measurements from almost everywhere, all year, for many years. You can’t just stick your head out the window and tell if global warming is happening or not.

But there are some scientific questions you can answer by just looking out the window.

One of them is the question about whether there is an infinite number of stars in the universe. Now, we have all heard about the astronomers who have looked far out into space and, starting with Edwin Hubble, reconstructed the history of the universe. But what if you don’t have a big telescope? You can answer the question anyway.

The brightness of a star decreases as the square of the distance; a star twice as far away is four times dimmer. Therefore, very faraway stars are practically invisible to most of us. But if there were truly an infinite number of stars, their light, however faint, would add up to an infinite brightness. (Hard to believe? Well, what part of infinite do you not understand?) When you look out the window and see that the sky is dark at night, you know that the universe is finite.

You could solve the problem by putting it into the form of integral calculus. Maybe I could have done so back in 1976 when I understood calculus. But you don’t need to.

There are probably lots of other fascinating scientific questions that do not require equipment, a budget, or expertise to answer.