Thursday, October 24, 2013

How is a delphinium like a dolphin?

Sometimes it seems like everything is named for a resemblance to something else. This is a story of the similarity-based links among two flowers, three birds, and a cetacean. Oh, yes: and an amphibian.

I recently read a short story in which a New England matron establishes a garden club in her town because she's the local expert in delphiniums and lilies. By the magic of associative thinking, the constellation of Delphinus, the dolphin, sprang readily to my mind when I saw the word delphinium. What, I wondered, could possibly link the two? (Delphinus itself, a small constellation in the summer sky, is shaped like an elongated diamond; like most other constellations, it requires a good deal of imagination to see the thing it's named for.)

Beautiful view of a single delphinium
flower; you can see the nectary quite
clearly, although the dolphin  resemblance
does not appear to be strong for this
species. ©Tom Hilton under a Creative
Commons  Attribution License
The flower, as it turns out, is called delphinium, after the Latin word for dolphin, because the nectary (where the nectar comes from) sticks out behind the flower and is somewhat curved, resembling the sleek curvy front end of a dolphin. The back side of the flower, in other words, looks like the front side of the dolphin. Multiple flowers appear on a single stalk, each with a more or less extravagant projection behind it.

This would be the end of the story, except that the delphinium is also called the larkspur, because that nectary projecting out the back side also resembles the projecting structure called a spur on a lark's foot. (Technically, larkspur is used to refer to flowers in the genus Delphinium and also to some in the genus Consolida, We will leave Consolida for another day.)

This brings us to the other flower, the columbine (genus Aquilegia), which is named for not one but (possibly) two birds. These lovely airy blooms that dance in the spring breezes have inspired a number of imaginative comparisons. Aquilegia may come from aquila, the Latin word for eagle, because the flowers resemble the claw of an eagle. (Coincidentally, the constellation of Aquila appears not too far from Delphinus in the sky.) An alternative explanation is that Aquilegia comes from the Latin word for water bearer, because each part of the distinctive flower looks like an amphora, or water jug; amphorae typically had a pointed end that could be placed in soft earth to hold the jug upright.

The second bird this flower is named for is the dove, columba in Latin, because the flower as a whole is thought to resemble a group of doves. If the eagle story is true, this flower is named for both the warlike eagle and the peaceful dove.

At this point in my research, I became aware of a dim memory stirring in the back of my mind: Don't some churches have something called a columbarium? They do, and it's not where they keep the doves. It's a place for the proper storage of funeral urns containing the ashes of the dead. However, the urns are stored in an arrangement of compartments that is similar to that used in a dovecote.

Oh yes: the amphibian. The columbine and the delphinium are both members of the Ranunculaceae family. The family takes its name from the ranunculus, which in turn takes its name from the Latin for little frog. The resemblance here is not visual; like frogs, ranunculus like to live near water.

Friday, October 18, 2013

Midnight moths and primrose genes

Moonrise over White Sands. Image courtesy of Patrick Alexander
under a Creative Commons Attribution-
NonCommercial-NoDerivs License

It's easy to talk about science or science history in the abstract, especially when you're thinking about long stretches of time, and to lose sight of what it means to actually do science. So how about a video showing scientific research being done in the field?

Episode 4 of the series Plants Are Cool, Too!, "Sundrops and Hawk Moths," features host Chris Martine of Bucknell University and Krissa Skogen of the Chicago Botanic Garden. Skogen studies native pollinators (pollinators other than honeybees, basically), and the video shows her at work at the White Sands National Monument in New Mexico. She's looking at the interaction between the hawk moth and some primrose species at White Sands.

It's a cool video. I'd never seen anyone unroll a moth's proboscis and collect pollen from it, and I didn't know that you could gather the scent from a single flower and compare it with the scent from other flowers. One of the interesting things about the moths is that they cover much greater distances than bees and don't have any kind of a home to return to. The most evocative line in the whole video was the one about moths spreading the genes of these plants around. Not to mention that White Sands is a magical setting. Enjoy!

Full disclosure: My son, Patrick Alexander, Postdoctoral Curator at the NMSU Department of Biology Herbarium, helped with the production of this film.

Wednesday, October 16, 2013

The noble genus Vitis

Grapes growing in Montmartre in Paris. Because
it was June, they were nowhere near ripe. This part
of Paris has a long history of wine-making (and
wine drinking), from a Roman temple dedicated
to Bacchus to a medieval winery where nuns
pressed the grapes, and on into the present-day
cultivation of this old neighborhood vineyard.
The wine harvest is nearing its end, so this seems like a good time to look at the different species of grapes that are used for wine. When I first began to take a serious interest in wine, the differences between varieties and species were very fuzzy to me. I'm still sorting out the varieties, most of which come with fascinating but confusing historical baggage involving different names depending on the place and time.

Species are easier. For starters, all types of wine grapes fall within the genus Vitis, named for the Latin word for grape vine. Within that genus, most wine grapes are varieties of Vitis vinifera, although grapes from this species are also eaten fresh or dried. This species first arose in central Europe, southwestern Asia, and the lands around the Mediterranean. Because yeast occurs naturally on the grape skins, they would ferment if left to themselves. It's not clear when humans first discovered and exploited the products of fermentation, but they've been playing around with grape fermentation for a very long time.

Vinifera translates roughly from Latin as wine-bearing. Note that -fer (meaning carry or bear) is all over the place in other words: transfer (carry across), refer (carry back), Lucifer and phosphor (light-bearer; both used to be names for the morning star), and metaphor (carry over, in the sense of carrying meaning).

Vitis labrusca is a North American species that contains both varieties used for wine and varieties used in juice or jam (for example, the Concord is a V. labrusca variety).  Labrusca is the Latin word for a wild grape, and these grapes are noted for a particular earthy musky flavor. The wines they make are very grape-juicy, maybe not ultra-sophisticated but very appealing in their way. Catawba and Niagara are probably the varieties you're mostly likely to see in wines.

Wines are also made from the North American grape Vitis aestivalis. Aestivales comes from the Latin word for summer, although it's not clear why that name was given to this species. The cultivar Norton is thought to be the first American grape used in commercial wine production, and it's still an important grape in Missouri and parts of the eastern US.

Vitis riparia, named from the Latin word for the riverbanks where it likes to grow, is important for wine because it is used as a root stock that provides V. vinifera grapes with genes for cold tolerance, disease resistance, and resistance to phylloxera. Another grape used as root stock is Vitis rupestris; rupestris is a botanical and zoological term that comes from Latin; it means essentially living on or near rocks and appears in other species names as well.

Phylloxera is historically one of the most notable grape pests; it swept through Europe in the late 19th century, inspiring viticulturists to use resistant root stocks and develop hybrids. In the name phylloxera, we once again encounter the Greek root phyllo (leaf), which we have seen before in chlorophyll and phyllosilicate. The -xera part of the name comes from a Greek word for dry; we also see it in xeroscaping (landscaping in dry areas with native desert plants) as well as xerography and Xerox (the company applied a "dry" process of photographic duplication that did not involve the use of a liquid developer). Phylloxera is a pest that sucks the sap from the roots and leaves of grape plants.

Of course, this simple picture is made tremendously more complex (and more rewarding) by the presence of so many varieties of wine grapes within the species V. vinifera, each suited to a particular climate and soil type, not to mention the existence of many hybrids. But getting into that would take a lifetime.

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Friday, October 11, 2013

Infinitesimal calculus and renal calculus

I ran across the phrase renal calculus, another name for a kidney stone, and wondered whether it was related to the calculus you learn in a math class. It turns out that it is, and the link is limestone.

Calx is the Latin word for limestone; it comes from the Greek word khalix, or pebble. The diminutive form of calx in Latin, calculus, was originally used to refer to a pebble used for counting and simple calculations. The Latin word calculus thus forms the basis for the English word calculate

Calculus can be used in English to refer to any system of calculation using symbols, although it is used primarily for the indispensable mathematical tool developed by Leibniz and Newton in the 17th century to describe and study change. This was originally called the calculus of infinitesimals, later shortened to infinitesimal calculus; I think this is why you sometimes hear people talking about, for example, the history of the calculus instead of simply the history of calculus.

It's obviously a short step from the pebbles used to reckon your accounts to the pebbles that cause such misery in the urinary system or in the gall bladder. Calculus is now used to refer to any type of accidental accretion in the body. Now that I think about it, I have vague recollections of puzzling over the thought of calculus on the teeth, perhaps when I was the target of a dental health campaign in grade school. Dental calculus is essentially hardened plaque, perhaps the first step on the road to gum disease. I will generously share all of what I remember learning about it: Brush! Floss!

The Latin root calx also made it into English in the name of the element calcium, which is a major constituent of limestone (and coincidentally is also found in some kidney stones). Renal, by the way, comes from the Latin word for kidney, ren.

Learn more:
  • Why Do We Study Calculus? gives a brief history of calculus and its applications and explains why it's worth learning
  • Free online math courses at Open Culture
  • French composer Marin Marais wrote "A Description of the Removal of a Stone" in 1725, which is thought to depict the horrors of an operation to remove a bladder stone (the first gallstone operation didn't occur until later). This article lists the brief descriptions in the score, which are worth reading, but note that the article identifies the operation, apparently incorrectly, as a gallstone removal. 
  • [Added October 23]: A friend sent links to an analysis and a performance of the Marais piece. 

Wednesday, October 9, 2013

Geological epochs and regrettable barbarisms

The other day I was poking around online reading about rocks and dinosaurs when I should have been working, as people do, and I discovered that what I knew as the Cretaceous–Tertiary (KT) boundary is also called the Cretaceous–Paleogene (KP) boundary. (K is used instead of C to make it easier to pronounce.) You may be familiar with this boundary as marking the extinction of the dinosaurs roughly 65 million years ago. Well, one thing led to another, and I learned some interesting things about the names of recent geologic periods and epochs.

Geologists originally categorized Earth's crustal rocks from oldest to most recent as Primary, Secondary, Tertiary, and Quaternary. Because each type was associated with a particular period in Earth's history, you could also talk about, for example, the Tertiary period. However, most of these geological time periods have since been placed into a larger framework, broken down into finer-grained subdivisions, and given generally more informative names.

As part of this process, the Tertiary (66 million to 2.6 million years ago) and the Quaternary (2.6 million years ago to the present day) were once assigned to the Cenozoic era. (Eras are longer than periods but shorter than eons.) However, as scientists learned more about the fossils of the Cenozoic, it began to make more sense to split the Tertiary itself into two periods, the Paleogene and the Neogene, on the basis of the fossils found in rocks of each period. These names were proposed in Europe and adopted only slowly by North American geologists.

The Paleogene is the older of the two periods; the name comes roughly from the Greek phrase ancient-born. However, it's part of the Cenozoic era, which translates more or less as recent life. (The Cenozoic is preceded by the Mesozoic and Paleozoic: middle life and ancient life, respectively.) Ceno- comes from the Greek word kainos, meaning new or recent, and we also see this root in the -cene ending in the sequence of epochs running from the Paleocene to the Holocene.

Wait, Paleocene? Wouldn't that mean something like ancient recent? Indeed it would. Not only is the Paleogene (ancient-born) part of the Cenozoic (recent life), but the Paleocene epoch could be translated as something like the ancient recent epoch.

It actually makes perfect sense. Compared to the Paleozoic, which stretches from 541 million years ago to 252 million years ago, the Cenozoic is recent indeed. However, the Cenozoic itself contains older and more recent epochs. Imagine that you trade in your old car for a new one frequently; you may find yourself explaining to a confused friend that the Toyota was your old new car, and your new new car is a Honda. It's something like that with the -cene epochs, all more recent than what came before but needing to be subdivided somehow according to their relative ages.

From oldest to most recent, these epochs  are the Paleocene, Eocene, Oligocene, Miocene, Pliocene, Pleistocene, and Holocene. The names Paleocene and Holocene make nice bookends: the ancient recent epoch and the entirely recent epoch (holo- comes from the Greek word for whole, which we also see in holographic and holistic). The epochs in between make sense, although evidently not if you know much about Greek grammar.

Eo- comes from eos, the Greek word for dawn, and is used to describe the earliest appearance of something, in this case modern fossils. Oligo-, mio-, plio-, and pleisto- are based on Greek words ranging in meaning from few to most, and they refer to increasing numbers of modern fossils, or increasing degree of recentness. H.W. Fowler, in his Dictionary of Modern English Usage, took a very dim view of these coinages, or, as he called them, "regrettable barbarisms." His entry for Miocene described the word as
A typical example of the monstrosities with which scientific men in want of a label for something, and indifferent to all beyond their own province, defile the language. The elements of the word are Greek, but not the way they are put together, nor the meaning demanded of the compound.
If this seems harsh, keep in mind that in the 19th century when these names were coined, every educated person was expected to have learned Greek. Fowler made this point not because he thought the words could be changed; he knew they were too well-established for that. His hope was that scientists "may some day wake up to their duties to the language—duties much less simple than they are apt to suppose." I'm guessing that he would also find the recent coinage Anthropocene similarly wanting or perhaps even worse. However, he is not here to comment, and my more recent edition of Fowler's Modern English Usage, edited by R. W. Burchfield, is far more temperate, noting that "the time has come for the hatchet to be buried. A simple irreg. suffices" to characterize these words.

The geologic time scale is a fascinating thing full of evocative names. We'll come back to it again, I'm sure.

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Monday, October 7, 2013

Season of anthocyanin and carotenoids

Fall color on the Mogollon Rim, Arizona,
October 2009. Photo by Gary Garner.
Credit: U.S. Forest Service, Southwestern
Region, Coconino National Forest. Made
available under a CC License.

This is one of my very favorite times of year; on sunny days, the low-angle sunlight makes the colorful leaves on the trees glow. "Season of mists and mellow fruitfulness," Keats wrote in his poem To Autumn, but it's also the season of some interesting chemistry. To celebrate the brilliant hues of Northern Hemisphere autumn, today we'll look at the names of the chemicals that give the leaves their color.

The green in leaves in the spring and summer comes from chlorophyll, the chemical that makes photosynthesis possible. The word chlorophyll was coined in the early 19th century. It has two Greek roots. Khloros means pale green, and phyllon means leaf. (We've seen that one before, in phyllosilicate, which describes clay minerals with thin sheets, or leaves, of silica; it also appears in phyllo dough.)

Leaves also contain carotenoids during much of their lifetimes. These pigments provide yellow, red, and orange colors in the plant world. For example, in about six months we'll be seeing the cheery yellow of a carotenoid in daffodils. As some fruits mature, we see the chlorophyll slowly disappear as the green fruit ripens to yellow, orange, or red. You may have heard of lycopenes or β-carotene, which are considered micronutrients in foods. (I talked about lycopenes and their unlikely etymological connection to wolves in an earlier post.) The words carotene and carotenoid come from carote, the Latin word for that iconic orange vegetable, the carrot.

Something similar to the ripening of fruit happens in leaves in the fall: as trees prepare for winter and shut down photosynthesis in their leaves, the chlorophyll fades away and the carotenoids that they contain become more obvious. In addition, some fruits and many trees also begin to produce another pigment, anthocyanin, in response to the shorter days of fall. It also contributes to the colors of the fall foliage as the chlorophyll disappears. Anthocyanin, like chlorophyll, comes from two Greek roots: anthos, for flower, and kuanos, for blue.

So now you know what sets the woods and tree-lined streets ablaze: the chlorophyll is disappearing, and the carotenoids and anthocyanin are shining forth. It goes by fast; enjoy!

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Friday, October 4, 2013

Happy Sputnik Day!

On October 4, 1957, the world launched its first satellite, Sputnik 1, into Earth orbit. Yes, it was specifically the part of the world identified at the time as the USSR, but I hope that in time it will be seen as the purely human achievement it was. In honor of this satellite launch, which began the space age and pushed the US into a ferment of frustrated pride and compensatory science education, we'll look at some spacecraft named for notable humans. (Sputnik, by the way, is simply the Russian word for satellite.)

The first name that comes to mind when you think of satellites named for humans may be the Hubble Space Telescope, named for Edwin Hubble. His achievements were many, but the high points are his discovery that the spiral nebulae are actually independent galaxies separate from our own, and that the light from these galaxies is redshifted in proportion to their distance. (He also played basketball at the University of Chicago and taught at a high school in New Albany, Indiana.)

The successor to Hubble, the James Webb Space Telescope, is named for NASA's second administrator. Webb was in office from February 1961 (a few months before Alan Shepard became the first US man in space) until October 1968, shortly before Apollo 8 flew to the moon and orbited it. He left office to free Lyndon Johnson's successor to appoint his own NASA administrator. Leaving NASA in October 1968 seems like it must have been a difficult sacrifice. The JWST is planned for launch in 2018.

The Hubble Space Telescope was one of NASA's Great Observatories. The others were:
  • the Compton Gamma Ray Observatory, named for Arthur Holly Compton, who won the Nobel Prize in Physics in 1927 for work in gamma ray physics
  • the Chandra X-ray Observatory, named for Subrahmanyan Chandrasekhar, another Nobel Prize winner (1983) for his work on the death throes of massive stars (Chandra also means moon in Sanskrit.)
  • the Spitzer Space Telescope, covering the other end of the spectrum in the infrared; it was named for Lyman Spitzer, Jr., an astronomer and an early proponent of space-based telescopes
You may have heard this summer about a new map of the cosmic microwave background, the remnant radiation from the Big Bang. That map came from data from Planck, a European Space Agency mission that has been examining the CMB, which is quite smooth, for irregularities that might indicate the origins of the clumpy structure of today's universe. Max Planck was a German physicist who won the Nobel Prize in Physics in 1918 for his work in establishing quantum theory.

Some notable missions have been named for much earlier astronomers. Cassini, a NASA mission that's been orbiting Saturn and making spectacular observations since 2004, is named for Giovanni Cassini, a 17th century astronomer who discovered four of Saturn's moons and the most prominent of the gaps in Saturn's rings (now called the Cassini Division). The mission included a probe that landed on Saturn's largest moon, Titan. The probe was named Huygens, after another 17th century scientist, Christiaan Huygens, who discovered Titan and made many other contributions to science.

Galileo, a similarly long-lived and successful NASA mission that explored Jupiter, is named for Galileo Galilei, one of the great figures in the history of science and the first to turn a telescope onto the night sky and write about what he saw there.

Johannes Kepler, who lived around the same time as Galileo and formulated the three laws of planetary motion that made sense of planetary motion in the solar system, also has a space-based NASA observatory named for him. The Kepler mission monitored the brightnesses of stars to look for minute periodic differences that would indicate the presence of a planet crossing the face of a star and blocking some of its light. It has found 134 confirmed exoplanets and another 3,277 candidates. Although the mission is halted at the moment due to an equipment failure, it may yet continue its search.

The last two missions I'll mention are named for scientists who lived much earlier than any of the others I've talked about. India's first satellite was named for Aryabhata, an Indian mathematician and astronomer who lived in the sixth century of the common era and had some astonishingly accurate knowledge of the solar system for his time. The satellite was used to conduct astronomical research for four days in 1975. The Greek astronomer Hipparchus lived even longer ago, in the second century before the common era. Hipparcos, an ESA mission, was named for him; the name is actually a somewhat strained acronym for High precision parallax collecting satellite. It gathered extremely precise data on the positions of well over 100,000 stars, providing a very accurate catalog to join the other astronomical data sources I wrote about in an earlier post.

Although science is not generally connected with warm human feelings or meaningful human traditions, these names illustrate the continuous thread of international human connections and memories that runs through astronomy and physics. They remind us that despite Cold War competition and other rivalries, a similar thread runs through every field of science.

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Wednesday, October 2, 2013

How are your muscles like mice?

The word muscle comes from the Latin musculus, which means little mouse. But why? It's because the rippling movement of certain muscles under the skin was thought to resemble the movement of a mouse. My mental image—and it is not a pleasant one—is of a mouse running or moving underneath a thin rug or blanket. Although it's an unnerving image, I can see the connection.

The Greek word mŷs can also mean either mouse or muscle; this word gives us the prefix myo-, as in myalgia (muscle pain) or myocardial infarction (damage to or death of the muscular tissue of the heart due to lack of oxygen).

While we're looking at the human body, we can examine another unexpected connection, this one between the skeleton and arteriosclerosis, or hardening of the arteries. Skeleton is ultimately derived from the Greek verb skellein, to dry up, via skeletos (dried up) and skeletos soma (dried-up body).

Skellein is related to skleros, meaning hard, a natural enough association with dried things. This made its way into Latin and then English as sclero, which is combined with other roots to form words. It appears in the the word scleroderma, for example, the name of a skin condition, often painful, in which the skin becomes hardened. And arteriosclerosis is any thickening and hardening of the arteries.

So there you have it: muscles like mice and a skeleton consisting of what's left after everything else has dried up and blown away. I look forward to investigating more of the poetry of anatomy.

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