Two Scotsmen and a tree

The story of Scottish botanists Archibald Menzies, David Douglas, and the tree that bears both their names is a good example of the challenges of establishing either a binomial name or a common name for newly observed species. (Incidentally, the name Menzies is pronounced “MING-iss.”)

The tree is the Douglas fir, common in the forests of western North America, particularly in the Pacific Northwest. I learned recently that some people prefer the name Douglas-fir, with a hyphen, because it’s not a true fir. This is only the beginning of the complexities of this tree’s name. Today it’s one of the most economically important timber trees worldwide and is popular as a Christmas tree, but for many years it was quite a puzzle to botanists.

The name Douglas-fir honors David Douglas, who botanized in the New World during his brief but adventurous life in the early 19th century. Born in Scone, Scotland, he received training in botany in Scotland and made three plant-collecting expeditions for the Royal Horticultural Society of London. During his second and most successful trip (1823–1827), which took him to the Pacific Northwest, he introduced about 240 plant species to the British Isles, both garden plants and various timber trees. In 1827, he sent seeds from the Douglas-fir back home, estimating that this tree would do well there. Indeed, a tree grown from one of his seeds still graces the grounds of Scone Palace.

Photograph of Douglas fir.
Douglas fir on the grounds of Scone Palace in Scotland, which was grown from a seed sent home by Douglas in 1827. ©Aaron Bradley under a Creative Commons license.

The journal of Douglas’s second North American trip tells of his travels and work under often difficult conditions, albeit in spectacularly beautiful places. On his third trip, Douglas returned to the Pacific Northwest and also visited Hawaii. It was there that he met his tragic and peculiar death at the age of 35. He died on Mauna Loa after he accidentally fell into a pit trap and was trampled by a wild bull. His name lives on (as douglasii) in the scientific names of more than 80 species of plants and animals.

Douglas was one of the first Europeans to climb Mauna Loa. The very first Europeans included Archibald Menzies, who climbed it with two other people in 1794 when he was serving as naturalist on the Vancouver Expedition of 1791–1795. Menzies was a doctor and botanist whose name also appears in the names of various New World plants that he observed and collected, including the scientific name of the Douglas-fir.

He visited the Pacific Northwest, where he collected specimens of the Douglas-fir and sent them back to England, but for some reason the tree evidently did not enter cultivation there at that time. Lewis and Clark also observed the tree and contributed drawings (and possibly specimens, although if so they are now lost) to fuel the discussion of how to categorize it and come up with a suitable scientific name.

This turned out to be a long and complicated business because of confusing resemblances to more familiar trees. Various genera were suggested: Pinus (pine), Tsuga (hemlock), Picea (spruce), and Abies (fir). The genus Pseudotsuga (false hemlock) was introduced in 1867, but the official name of Pseudotsuga menziesii was not formally accepted until the 1950s.

It’s quite a story, and I only hit the high points. This is an excellent example of how the elegance of binomial nomenclature often represents the distillation of many observations of an organism over a long and fascinating history. If you enjoy reading about scientific explorers, check out the writings of Douglas and Menzies listed below.

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Binomial nomenclature (and Lady Gaga’s ferns)

As I mentioned in an earlier post, common names, although rich in lore, are not always all that helpful for uniquely identifying an organism. They also don’t reflect the evolutionary history of organisms or the relationships among them. That’s why scientists eventually devised a system they could use to communicate unambiguously.

After the concept of species was introduced by John Ray in 1686, natural scientists experimented with conventions for naming species. In 1735, Carl von Linne (aka Carolus Linnaeus), a Swedish botanist, introduced his system of binomial nomenclature for plants and animals. Binomal indicates that each organism has two names; one is the name of its genus, which it shares with other organisms in the genus, and the other is its trivial name, also called the specific name or specific epithet, which is unique to the species. The system is governed by two international bodies, one for animals and one for plants.

Latin grammar is applied to binomial names; for example, menziesii translates as “of Menzies” and is used for several species to honor Scottish botanist Archibald Menzies (about whom we will hear more soon). As this example shows, the specific name doesn’t have to describe the organism; it can name a person (typically but not always a discoverer), a location, or a real or imagined resemblance.

Although the names are formulated according to the rules of Latin grammar, they can originate in other languages. In at least one instance, Greek and Latin roots are both used in the same name: the swordfish, Xiphias gladius. Xiphias comes from the same Greek root (sword) as xiphoid, which describes the blade-shaped xiphoid process in the human body, and gladius is from the Latin word for sword. The name seems to be saying: “Did I mention that this fish has a sword?” Incidentally, you also see gladius in the word gladiator, for obvious reasons, and perhaps more surprisingly in gladiolus, because of the swordlike leaves. (So now you know what the gladiator and the gladiolus have in common.)

Photograph of the grass side-oats grama.
Bouteloua curtipendula, or side-oats grama, the state grass of Texas. The genus is named for two Spanish botanists, Claudio and Esteban Boutelou. Curtipendula can be translated very roughly as “short danglies,” in reference to the way the seeds hang from the side of the stalk. ©Matt Lavin under a Creative Commons license.

Last year, researchers at Duke named a genus of ferns for Lady Gaga, on the basis of various resemblances and the presence of the DNA sequence GAGA. This illustrates, among other things, the role that DNA studies play today in determining the boundaries of genera and species. The new genus contains 19 species of ferns, 17 of which were previously assigned to the genus Cheilanthes on the basis of their physical appearance. The reclassification to the genus Gaga, in contrast, is based on an analysis of their DNA. The names of the two new species, Gaga germanotta and G. monstraparva, commemorate Lady Gaga’s family name and her name for her fans (little monsters), respectively.

Note that once you’ve named the genus, you can abbreviate it (G. monstraparva). If you’re talking about an unknown species within a genus, say the genus of sunflowers, you can use, Helianthus sp., and for several species within a genus, you can say, for example, Gaga spp. Binomial names can be followed by the name of the person who first published the name (an authority) and perhaps the date of the original publication. They can also be further qualified by the name of a variety (a variant found in nature) or a cultivar (a variant developed by humans). For example, the Carnegie cultivar of the garden hyacinth is called Hyacinthus orientalis L. “Carnegie” (where the L. indicates that Linnaeus is the authority).

As I hope the examples above show, binomial nomenclature is simultaneously an elegant and precise system and a rich repository of historical information. We’ll be exploring lots of these names in this blog.

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Who put the meteors in meteorology?

While we’re on the subject of meteors, what have meteors got to do with meteorology? It turns out that the link between meteors and meteorology is a Greek word, meteoron, that refers to things in the air, or sky—what today we would call atmospheric phenomena. Clouds, lightning, rain, storms, wind: these are all features of the sublunary sphere (below the moon), where things were changeable and imperfect, in contrast to the unchanging perfection beyond it. Meteors were also thought to be purely atmospheric.

Meteors are in fact an atmospheric phenomenon, but, contrary to Greek cosmology, they originate much further out. However, it didn’t make sense at the time that something so fleeting could come from the supposedly perfect and unchanging realms beyond the sublunary sphere. The name meteorology for the study of the other atmospheric phenomena stuck, however. Meteorologists do talk about hydrometeors, but they have nothing to do with the interplanetary kind of meteor; they’re water droplets or other types of precipitation that form in the atmosphere by condensation.

The astronomy–astrology link is also interesting. When I was an undergrad studying astronomy, I was startled and mildly annoyed at how many people got the two confused. Sometimes it was just a slip of the tongue; the words are quite similar. Sometimes the confusion was deeper. One time, for example when I was reading a copy of Astronomy magazine, a co-worker asked me, in all seriousness, “Do you really believe that stuff?” After various similar discussions, I became somewhat sensitive on this point.

However, at one time astrology was astronomy, the study of the heavens. There were essentially two types of astrology: natural and judicial. Natural astrology concerned itself with figuring out the tides and the seasons and similar natural phenomena that result from the Earth’s interaction with other bodies in the solar system. Eventually these pursuits segued into what we now call astronomy. Judicial astrology involved more speculative investigations of how celestial events affected humans directly, e.g., linking their personality to the positions of the planets when they were born, or the course of a disease to the influence of the moon or planets. The word judicial refers to the fact that astrologers made judgments about what they thought was going on, which differed from the more numerical and observational nature of natural astrology.

Illustration of Kepler spacecraft.
Artist’s conception of the Kepler spacecraft. Johannes Kepler, the astronomer for whom this mission is named, also cast horoscopes. Image courtesy of NASA/Ames/JPL-Caltech.

Today we have better explanations for personalities and diseases, and astrology is recognized as unfounded nonsense. However, it was only within the last few hundred years that the astronomy–astrology boundary that we know today became firm. Kepler, who figured out that the planets have elliptical orbits and formulated three laws describing planetary motion, also earned money by casting horoscopes. Interestingly, he has both a scientific satellite and a school of astrology named after him: the Kepler mission to search for extrasolar planets, and Kepler College, which offers online training in astrology.

More recently, astrophysics became recognized as separate from astronomy. Before the dazzling revolution in astronomy brought about by the introduction of photography and spectroscopy, astronomers could study the positions and motions of heavenly bodies but not their compositions or other characteristics, which severely limited how much they could figure out about their evolution. With spectroscopy, astronomers could determine a star’s composition and temperature, how fast it was rotating, and other features—stellar spectra reveal an astonishing amount of information!—and also begin to categorize stars and figure out how they formed and aged. Thus was born astrophysics, which focuses on the chemical and physical properties of stars, galaxies, and other objects. So there you have it: astrology to astronomy plus astrophysics by a series of interesting transitions.

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The meteor family of words

Sometimes words that describe the natural world come in a rather confusing clump. I’m hoping to explore many of these groups of words describing interrelated or similar concepts. Because one of the best-known meteor showers, the Perseids, is peaking this weekend, let’s start with the meteor family of words.

A meteor, of course, is that thin needle of light streaking through the night sky that we also know as a shooting star. Meteor showers occur when Earth passes through the swath of debris left by a comet. We’ve identified the comets that have spawned various meteor showers; the Perseids are the leftovers of Comet Swift-Tuttle. The showers themselves, by the way, are named for the constellation from which they appear to come, in this case Perseus.

Several other words are also used to describe interplanetary dust and fragments more precisely.

  • A meteoroid is a bit of debris that would become a meteor if it entered Earth’s atmosphere. They’re much smaller than asteroids and range from tiny dust grains to pieces about one meter across—essentially the dust bunnies of the solar system on up to things the size of maybe a washing machine. Think of asteroids and planetoids and remember that all three are out in space.
  • A meteorite is a meteor that survives its journey through the atmosphere. Most meteors are so small that they simply vaporize in the atmosphere, but the larger ones can make it down to the surface. Both meteorites and meteors add their mass to Earth’s; it’s hard to tell exactly how much mass this amounts to, but estimates range from 37,000 to 78,000 tons per year, most of it from tiny bits of dust.
  • A particularly big, bright meteor is sometimes called a fireball. The best-known recent example of this is the spectacular fireball that streaked across the sky near Chelyabinsk, Russia in February 2013. A large meteor that explodes in the atmosphere is called a bolide, from a Greek word meaning missile. The Chelyabinsk meteor broke up in the atmosphere and was so large that it’s also called a super-bolide.
  • Sporadic meteors are random bits of space debris that are not associated with a particular comet. They might be fragments of asteroids that broke up, or bits of the moon or Mars that were ejected during an impact. Some of the latter even make it down to the surface sometimes; enough of these have been identified as coming from Mars that they are classified into different types.

The next time you’re out under a dark sky and see a fleeting thread of light appear in the starry sky, remember that you’re watching the end of a long space odyssey, signaled by the tiny quiet flash of vaporization as a bit of space dust becomes part of Earth.

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Who names things?

Most of the time, names arise mysteriously out of the collective creativity of language. Common names for plants and animals are a very rich source of information about them and their history of interaction with humans. One inspiration for this blog was a desire to learn where names like wormwood, sassafras, and lungwort came from. However, they have their limits. Is your moonflower or ironwood the same as mine? Maybe, maybe not. And consider things like Spanish moss, which is neither native to Spain nor a moss.

When scientists communicate with each other, they require clarity and a shared understanding of the names and categories of the things they talk about. Various professional societies for scientists have naming commissions or other bodies that agree on nomenclature in that field. For example, it was the International Astronomical Union that decided that Pluto is a dwarf planet. Although this demotion caused consternation in some circles, it wasn’t anything personal. It just reflects the current understanding of the contents of the solar system better. The idea is essentially to use the same name only for objects that not only resemble each other superficially, but that share deeper similarities and perhaps an evolutionary history.

The ultimate example of precision naming may be the binomial nomenclature used to give consistent names to plants and animals. Each name indicates the organism’s genus and species. The species name often reflects something about the organism (a word describing its appearance, say, or the name of the person who identified it as a species). Virginia creeper, for example, goes by Parthenocissus quinquefolia; it belongs to the genus Parthenocissus, and quinquefolia refers to the fact that the leaves (the folia bit) appear in groups of five (the quinque bit). In this blog, we’ll learn about how the genus names were established and also about some of the scientists and explorers whose names live on in scientific names.

Photograph of Virginia creeper.
Virginia creeper, also called five-finger, with its groups of five leaves (quinquefolia). I assume Virginia is the first place that Europeans saw this plant. Its range is actually much wider than the name indicates. They don’t call it a creeper for nothing, though. Here’s some creeping through a flowerbed.

As we learn more about the evolutionary history of an animal or a plant, the scientific name may change. Again, the goal is to group objects that truly are related in a meaningful way. I was surprised to learn that Virginia creeper is not Hedera quinquefolia, the first name I learned it by many years ago. That’s an older name that is synonymous with Parthenocissus quinquefolia (that is, it refers to the same thing) but is not used any more in scientific publications or databases. (The genus Hedera contains the ivies, and although Virginia creeper resembles an ivy in behavior, it turns out not to be particularly closely related to them.) You can see that scientific names are not quite as cut and dried as they may seem, but the goal is a clear unambiguous naming convention that reflects our best understanding of the natural world.

Even scientific names have some scope for whimsy, however. Asteroids and genes, which are generally named by their discoverers, are two good examples. Asteroids have been named for people from Pythagoras to Lennon and McCartney. There are asteroids named Paris, Potsdam, Cincinnati, Tahiti, and even Peruindiana (after a small town in Indiana, which by the way is generally pronounced PEE-roo). Some are named for fictional characters: Mr. Spock, James Bond, and Desdemona, for instance. There’s also one called Racquetball, and one called Vinifera (named by a wine lover, I assume). And speaking of wine, the zebrafish has a group of genes named for wines and a gene called moonshine that have to do with blood cell development and blood circulation, respectively.

So maybe it’s more accurate to say that all names arise out of the collective creativity of language, and that science tries to use names more precisely than we often do.

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Why do they call it that?

I edit scientific papers; although my background is in astronomy, geology papers may be my favorite. I love the lingo of geology—greywacke, gneiss, drumlin, plagioclase feldspar, obsidian, alluvial fan—and I’ve always been curious about the origins of some of the more exotic terms. When I started to investigate them, I found that even common terms often have an interesting etymology.

Closeup photograph of granite.
This photograph of granite used in the facade of a building at Cambridge illustrates its granular texture very nicely. ©James Bowe under a Creative Commons license.

Granite, for example, springs from the same root (so to speak) as corn—not necessarily the corn that we call corn today, but in the older sense, in which the word refers to the local grain crop. Granite has a granular texture, and the Latin word granum is the ultimate source of the words granite (from the past tense of the verb grano, “to make grainy”) and corn. All right, I thought, these geology words are well worth pursuing.

Then I was having lunch with my son a few days later and he told me that his then six-month-old son, a born kicker, had recently kicked him in the xiphoid process (a small bone spur in the chest). I sympathized, but at the same time, the phrase “kicked in the xiphoid process” made me giggle. (It could be hazardous if an adult were to kick you there; however, a xiphoid kick from a baby is an uncomfortable indignity but is not likely to be lethal.) And again I wondered, why do they call it the xiphoid process? How about the sigmoid process? What is a process, anyway?

One last story: I was sitting near some people at a coffeehouse and inadvertently overhearing their discussion; for some reason they needed to know whether a centrifugal force pulled inward or outward. One of them reasoned that because of the way a centrifuge works, it must go outward, which was an excellent way to approach the question. Another nice approach is to remember that the Latin root fugere means “to flee” (a mnemonic is the phrase “Tempus fugit,” which translates literally as “Time flees”), so under a centrifugal force, objects flee the center of a circle. We can also trace fugitive and refugee back to fugere.

Put all this together, and it occurred to me that learning more about the Latin, Greek, or other roots of scientific words and/or the stories of their origins is a great way to understand more about science and its history. Hence, this blog. I’m going to explore the answers to my questions about rocks, minerals, and processes, along with many other things, and share what I learn here. I hope this will be a helpful and entertaining site to anyone who is curious about science and wants to learn the stories behind the curious and often beautiful words it uses, as well as the history hidden behind very familiar words.

About

Science Word Geek is where my interests in words and science converge. I have a bachelor’s degree in astrophysics and a lot of experience editing scientific papers, where I still run into words I’ve never heard of or words that intrigue me.  I’ve also been a fan of the written word since I got my first library card at age 4.

More importantly, I think that understanding why things are named as they are and where scientific terms comes from can help make scientific knowledge more a part of anyone’s mental furniture. If you know some of the Greek, Latin, Arabic, and other roots, and some of the history of concepts and the scientists who formulated them (even the ones that turned out to be wrong), it’s easier to fit new scientific knowledge into the context you’ve built up in your mind.

Perhaps most importantly of all, science, like any human endeavor, is full of interesting characters and fascinating stories, and its language reflects this. The lingo also captures some of the thought processes that went into developing scientific knowledge, and the history of the times in which the terminology emerged. I hope you’ll be as entertained and enlightened by these stories as I am.

So what does make humans unique?

I went to hear a talk by Dr. Kim Hill on the origins of human uniqueness. Hill began by framing our uniqueness in terms of our energy usage and biological dominance—for example, the fact that we cycle more nitrogen than all other terrestrial lifeforms combined, and we represent 10 times more biomass than any other large species that ever lived. We also exhibit extreme social complexity and specialization; no other species has anything remotely resembling the New York Stock Exchange or the NCAA basketball tournament, for example. Moreover, even before agriculture, we had colonized every landmass, and hunter-gatherers exhibited unusually complex social behavior compared to that of other animals. However, although we exhibit non-unique traits that arose through non-unique processes, we somehow turned into this distinctive species. The question is, how?

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My brain, hallucinating

I recently picked up Hallucinations, the latest book by Oliver Sacks, at the library. In the introduction (all I’ve read so far), he subtly echoes the language of William James when he talks about his wish to describe about “the great range, the varieties, of hallucinatory experience, an essential part of the human condition.” The headline of a recent interview with Sacks notes that he wants to destigmatize hallucinations. So this seems as good a time as any to write a little about my own experiences with hypnopompic hallucinations, which occur when you’re waking up and can be bizarrely intertwined with dreams.
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The humanities, the sciences, and numbers

A few days ago I ran across a Scientific American blog post that struck me as interesting but somewhat disappointing: Humanities aren’t a science. Stop treating them like one. The writer, Maria Konnikova, begins by noting, quite reasonably, that precise, mathematical approaches to knowledge are not always appropriate. This idea that quantitative approaches aren’t universally applicable is repeated several times throughout the piece, but overall it sounds more like a “barbarians at the gate” polemic, only in this case the barbarians are the number-crunchers who are taking over the humanities. I was disappointed by this because I think there are a lot of interesting things to be said about when and where mathematical approaches should be used or avoided.Continue reading →