Freeze my head (but not yet)

After reading the latest issue of New Scientist, I think I may leave instructions to freeze my head when I die. It’s not because of any terrific new cryogenics method revealed by the magazine, but because of their series of short articles on extremophile organisms. You know, the thermophiles that can survive boiling temperatures (one microbe lived through a spell of 130° C (266° F), like the North American Wood Frog (Rana sylvatica), Painted Turtle (Chrysemys picta) hatchlings, and Woolly Bear caterpillars (Pyrrharctia isabella, which turn into the Isabella Tiger Moth) that can be frozen solid or nearly so and come to life again. Then there are the ones that can survive being dried out by “replac[ing] water molecules [in and around the cell] with sugar, turning their cytoplasm into a solid called sugar glass”. (New Scientist, 13 Nov 2010, p. 41). These are mostly small invertebrates. One in particular takes the survival prize: the tardigrade or water bear.

microphotograph of tardigrade or water bear,  phylum Tardigrada, part of the superphylum Ecdysozoa. They are microscopic, water-dwelling, segmented animals with eight legs.jpg

Microphotograph of tardigrade or water bear, in the phylum Tardigrada, part of the superphylum Ecdysozoa. They are microscopic, water-dwelling, segmented animals with eight legs. Unlike lots of microscopic animals, they do not seem to live by choice on or in humans, so you can study the photo without getting itchy. Photo source.

Because it is directly related to why I might want to freeze my head, let me quote from Wikipedia’s article on the tardigrade’s survival feats:

More than 1,000 species of tardigrades have been described. Tardigrades occur over the entire world, from the high Himalayas (above 6,000 metres (20,000 ft), to the deep sea (below 4,000 m) and from the polar regions to the equator.

The most convenient place to find tardigrades is on lichens and mosses. Other environments are dunes, beaches, soil, and marine or freshwater sediments, where they may occur quite frequently (up to 25,000 animals per litre). Tardigrades often can be found by soaking a piece of moss in spring water.

Tardigrades are able to survive in extreme environments that would kill almost any other animal. Some can survive temperatures of −273 °C (−459.400 °F), close to absolute zero, temperatures as high as 151 °C (304 °F), 1,000 times more radiation than other animals, and almost a decade without water. In September 2007, tardigrades were taken into low Earth orbit on the FOTON-M3 mission and for 10 days were exposed to the vacuum of space. After they were returned to Earth, it was discovered that many of them survived and laid eggs that hatched normally.

Below, a tardigrade in cryptobiosis (dried-out state) waiting for wetter conditions. Photo source.

a tardigrade in cryptobiosis (dried-out state) waiting for wetter conditions. The condition is called cryptobiosis.jpg

What the tardigrade means to me

The greater likelihood of…Life on Mars!

Areologists have found evidence to support the presence of surface water on Mars in earlier times (1, 2). On Earth, the one condition life seems to require is water in the environment. It can adapt to other conditions of astonishing harshness, as the extremophiles show. Therefore, if life developed upon Mars during the time of surface water, it is quite possible it has adapted to the new conditions.

One place to look for water and surviving life forms would be in the deep chasms of Mars, including Valles Marineris which is 1,860 miles long and in places reaches five miles in depth (five times the depth of the Grand Canyon). None of our probes has landed near chasms because we haven’t designed ways to explore them robotically. This is a job for human beings, and I am extremely disappointed that it hasn’t been done yet.

When I watched Neil Armstrong step onto the moon in 1969, I felt confident that the US and other nations would build on this accomplishment in what seemed a logical progression: space station, lunar base, a manned mission to Mars. I would not have believed that, 40 years after reaching the moon, only one of these elements would be up and running. That one, the International Space Station is a testament to the dedication of a few, but it’s not the robust establishment I expected; it seems to be on a precarious footing in mechanical reliability, and in international support. The other two are as far from reality as they were in 1969—no, farther, because the momentum of the 1960s has drained away, and the world faces more serious problems than it did then. What was justifiably affordable then, may not be now.

I don’t view space exploration as a luxury, or as an activity that merely satisfies our curiosity. It has much more to offer the species than that. We cannot say what we would have learned, what technologies we would have developed, had we followed the path I expected. Perhaps we would even have reached a slightly greater degree of wisdom about ourselves and or treatment of the planet, or maybe not.

But I do know how badly I want to see some questions answered, including “What life is there on Mars?”

And if looks as if, even if I eat my vegetables and exercise diligently, I may not live long enough in the normal course of events to find this out. So, freezing my head may be the only possibility. How can I let a bunch of tardigrades hear the news about Martian life, and not hear it myself?

Notes

1 Jakosky, Bruce M. et al. Mars’ volatile and climate history. Nature 412, 237-244 (12 July 2001).

2 Bowen, TA and Hynek, BM. Mars’ climate history as inferred from valley networks on volcanoes. Lunar and Planetary Science XXXIX (2008).

Etymological Notes

Rana sylvatica
rana, from Latin rana (frog); sylvatica from Latin sylvaticus (growing in the woods, wild)

Chrysemys picta
chrysemys, from Greek chrysos (gold) and emys (freshwater tortoise”)

Pyrrharctia isabella
Pyrrharctia, from Greek pyr– (fire) and arktos (bear—the animal, also used to refer to the north; here probably alluding to the hairy caterpillar, the “wooly bear”)
isabella, a word used to denote various vague colors: greyish-yellow, sand color, pale fawn, pale cream-brown or parchment; etymology uncertain but see here.

Tardigrada
Tardigrada, from Latin tardigradus (slowly stepping), from tardus (slow) and gradior (step, walk)

Ecdysozoa
Ecdysozoa, from Greek ekdusis (a stripping off) and zoon (a living being, animal; plural zoa)

Bonus for sticking with me to the end…

There’s one caterpillar just about everybody can identify, if only because of its supposed ability to predict the severity of the winter:

Woolly bear caterpillar, which becomes Pyrrharctia_isabella, the Isabella Moth.jpg

The Woolly Bear, of course, and the narrow band of brown on this one indicates a very tough winter to come. Photo by Rhys Alton from flickr.

But who among us knows what the Woolly Bear looks like when he or she grows up? Like this,

Pyrrharctia_isabella, Isabella Tiger Moth, which develops from the Woolly Bear caterpillar.jpg

the Isabella Tiger Moth (Pyrrharctia isabella), found in much of North America and Central America. The caterpillar overwinters, hence the ability to withstand freezing temperatures. The Woolly Bear has another distinction: the first insect known to self-medicate. It eats leaves from ragworts, groundsels and other plants that are rich in alkaloids, and these help rid it of parasites; infected caterpillars eat more of such leaves than uninfected ones. Yes, everything it seems has parasites; “Great fleas have little fleas upon their backs to bite ‘em, And little fleas have lesser fleas, and so ad infinitum”. And I, driven by the desire to know things, doubtless will need to know something else once my thawed-out brain has assimilated knowledge of our first manned mission to Mars.

The brightest beetle we’ve seen, and help identifying bugs

As long as I was on the topic of beetles, I thought I’d include this one which my husband photographed on Mt. Ashland in August during one of our wildflower walks.

Desmocerus aureipennis, male Elderberry Longhorn Beetle

The best resource I have found for identifying insects, if they are not among those illustrated in our insect field guides, is by using BugGuide.net. If you can narrow your search down, you may be able to identify it yourself by looking through the extensive pages of thumbnail photos for each group, genus, and species. That is how I figured out what this was,

Cyclosa conica CR0780.jpg

a spider named Cyclosa conica, for an earlier post—but I had to scan through dozens of pages of thumbnails to find this particular individual.

There’s another way: submit at least one good photo of the insect or arachnid in question to bugguide.net, with relevant details such as geographic location, time of year you saw it, and where (in your attic? under a log? on a rose bush?). Then a group of people who know lots more about bugs than you or I, will take a look, there will be perhaps some back and forth, and you’ll probably get a consensus. Before posting your photos you need to register an account with username and password, then after that you can log in and look at your photos and see what has been said about them.

BugGuide.net is hosted by Iowa State University Entomology, and a lot of the responders are extremely knowledgeable. Also, it is a collegial effort—they check each other’s work, in effect. But of course if the answer is really important to you: if this spider just bit you and your arm is swelling, or you have an orchard infestation of some bug, you want to talk to a real live person like a doctor or an ag extension agent. Try to get the bug into a little jar and take it with you.

This is a fun and educational site to browse through. There are pages of many-legged creatures awaiting identification (the better your photo, the better your chances, but send the photos you have), and of course a structure of pages organized by taxonomy, order/family/genus. Even better, on the left of each page is a visual key, a clickable guide composed of bugs by shape, to help you get close to the creature you are interested in.

The big red bug was not in our guides so I submitted it and got a precise ID. It is a Desmocerus aureipennis/auripennis, male. The females don’t have the bright red elytra, or wing covers. It’s one of a group called Elderberry Longhorn Beetles, and our photo showed it on that tree. I looked up other photos of this insect and yes, that’s what it is.

[Etymological note: desmocerus from the Greek desmos (banded or fettered) + keros (a horn) and aureipennis from the Latin aureus (golden) + penna (feather, wing).]

Biggest bug I was ever bitten by

One day this summer I was at the school where the food pantry is held, and a school landscape employee was spraying weeds. He called out in surprise, that there was a really big bug right on the nozzle of the herbicide applicator. I ran over to see and apparently was the only person willing to pick up this huge black beetle. I decided to take him home, since my husband is a beetle fancier, and rummaged around for some sort of container for him. Finally I found a kleenex box, emptied it, and with the help of a young girl gathered leaves and sticks to make a cozy temporary home. The little girl was scared of the beetle but her feelings toward him began to turn warm and nurturing when I invited her to help furnish his house. She hadn’t gotten up to touching him by the time we put him in and taped a piece of paper over the top, but given more time I feel sure she would have come around.

Here’s our prize, emerging from his house (all the furnishings got shaken to a corner by the car ride).

Ergates spiculatus Spined woodborer,emerges.jpg

He crawled on my arm and hand for a while and then I must have annoyed him because he bit me with his mandibles—made me jump! The bite made a 1/8 inch cut that did bleed, but alas left no scar for me to show off while admitting how I had completely deserved it. Below he’s on my husband’s arm.

Ergates spiculatus Spined woodborer - 15.jpg

And for better scale,

Ergates spiculatus Spined woodborer,4Scale.jpg

We were able to identify him as one of the longhorned woodboring beetles, the Spined Woodborer or Pine Sawyer Beetle (Ergates spiculatus). One clue to differentiating him from another similar species was the spininess of his thorax, visible in this photo. The spines are on the sides of his thorax, while the yellow arrows point to the palps which unfortunately are blurry in this picture.

Ergates spiculatus Spined woodborer Head.jpg

Here the palps are clearer.

Ergates spiculatus Spined woodborer palps.jpg

The palps are sensory organs for the beetle. Mandibles cut up food and maxilla help manipulate it. The parts of a beetle’s head are shown in this illustration.

Beetle head anatomy.jpg

After irritating this beetle so much, we stopped before getting any good photos of his underside, though we could see intriguing edges of fibrous stuff. Here’s someone else’s great picture of what the description says are “velvety” underparts. The eyes and two pairs of palps are also shown.

PaulBurnett'sPhoto.jpg

Etymological note: ergates is from the Greek, worker; spiculatus, from the Latin spiculum, a little sharp point (diminutive of spicum, a sharp point). The English word “spike” may derive from this Latin word, or may have a more indirect derivation; there is a Proto-Indo-European root *spei-, sharp point. [Proto-Indo-European is the common ancestor of all modern Indo-European languages. It dates from before writing, so it has been reconstructed from study of related words in various languages, and derivation of rules by which sounds change over time. The same method has been used to construct Proto-Germanic. In historical linguistic studies, the asterisk next to a “word” means that it is a reconstructed root.]

One site says this is the largest beetle in North America, up to 65 mm (2.6 inches) in length, but I could not confirm its status as champion big beetle. At any rate it is plenty large, and I wondered if it was one of those beetles, the larvae of which cause extensive die-off in our Pacific Northwest forests. A publication on wood-borers from Washington State University reassured me: “Keep in mind that almost all of our native species of long horned beetles feed in dying or stressed trees and do not attack healthy trees”. According to them, Ergates spiculatus feeds mostly on dead/dying/stressed Douglas firs or Ponderosa Pines.

That information has a different implication, however, at a time when climate change may be stressing northern forests with increased temperatures and long droughts, causing millions of trees to fall into that “stressed” category. British Columbia has reportedly lost about half of its pine trees to a borer no larger than a grain of rice, which spends most of its life boring beneath the bark, a process continued by its larvae which cut off the nutrient and water supply while feeding. To make matters worse, “The beetles also introduce a distinct blue stained fungus that holds back a tree’s natural defences against the attack, delivering a lethal larvae and fungus combination”.

Our trees look pretty good, though, so without hesitation we turned the big biting bug loose on one of them.

Ergates spiculatus Spined woodborer on tree.jpg

More about hydraulic mining, including some corrections

In an earlier post, about a walk along the Gin LinTrail, an area still scarred by hydraulic mining, I made errors that have been pointed out to me by a commenter on that post. I’ve made brief corrections to parts of my text in the original post, but will sort things out at more length here. On a couple of points, one trivial and the other important, I do differ with the commenter.

One error arose from my ignorance of the geological nature of the area where the hydraulic mining was done and the source of the gold. The commenter’s reference to Tertiary gravel deposits being the location of the gold was new to me, so I looked it up and learned a lot about the Northern California (and, I assume, extreme southern Oregon) hydraulic gold-mining industry.

The gold mined by hydraulic mining in Northern California was found accumulated in ancient “riverbed deposits, now elevated above modern rivers”. These deposits are 40 million years old, or older. So the hydraulickers, as they were sometimes called, were following a very old plane of deposited material across a large area which has since been raised, and also cut into, by modern geological forces such as uplift and water flow. The map below, from the UCSB Dept. of Geography, shows the location of those ancient rivers and their modern counterparts in one region of Northern California.

Map of ancient Northern California rivers which deposited gold and were mined by hydraulic miners.

”Pay streaks”, some ado about a phrase

With regard to the term “pay streaks”, of which the commenter said “A pay streak is a modern term used to describe a gold deposit that has formed in an existing waterway”, this term does in fact date back to the days of hydraulic mining and was used as I used it. For example, here is a passage from Hydraulic and placer mining by Eugene Benjamin Wilson (Wiley, 1918), page 8 (Google Books):

Pay Streak Quotation.jpg

It is easy to see how confusion may have arisen about this term’s early use, because of the change in meaning of another word: “placer”. Like other writers of his time and before, Wilson’s definition of “placer” is much more inclusive than what seems to be common usage today. We think of placer as meaning something deposited recently (in geological terms)

Placer definition.jpg

But Wilson and others of his era used it to refer not only to deposits in current rivers, but also to those made millions of years ago on riverbeds now under many feet of overburden.

placer quotation.jpg

(above, from Wilson page 11; below, from page 9) and

ancient&modern placers.jpg

His use of the the term “pay streaks” is in the half of his book about placer mining. For him, hydraulic mining is a method and placer describes a type of gold deposit including both recent and ancient riverbeds.

placer & hydraulic.jpg

(Wilson, page 152)

Another authoritative writer, Waldemar Lindgren, used “placer” in the same way (and “pay streak” also). In 1911 the U.S. Geological Survey published his opus, The Tertiary Gravels of the Sierra Nevada of California, as no. 73 in its series of Professional Papers. He says,

The occurrence of gold in paying quantities in the Tertiary gravels of the Sierra Nevada is limited almost entirely to the gravels in which quartz and metamorphic rocks form the principal components. …

DISTRIBUTION OF THE GOLD IN THE GRAVELS

It has become almost an axiom among miners that the gold is concentrated on the bedrock and all efforts in placer mining are generally directed toward finding the bedrock in order to pursue mining operations there. It is well known to all drift miners, however, that the gold is not equally distributed on the bedrock in the channels. The richest part forms a streak of irregular width referred to in the English colonies as the “run of gold” and in the United States as the “pay streak” or “pay lead.”
(Lindgren, p. 65-66)

Environmental effects of hydraulic mining

I blamed hydraulic mining for the unvegetated areas we saw along the Gin Lin Trail. The commenter blamed it upon poor soil in the areas of these ancient rivers, which he said was typical and something he has often observed. He said, “the deeper they were worked, the better the vegetation has recovered”.

The best description I found, in researching the revegetation of hydraulic mining sites, was this by Randall Rohe:

quote Rohe.jpg

(Source: Green versus gold: sources in California’s environmental history, by Carolyn Merchant. From the chapter by Randall Rohe, “Mining’s Impact on the land”, p. 128. Google books.)

So, all things being equal, the bottoms of hydraulic mining pits are most likely to revegetate quickly, while the slopes may remain bare for decades or centuries. However in some places the mining may result in contaminating the pit-bottom with minerals that are toxic to plants, such as seems to be the case here.

malakoff-diggins-pond-3.jpg

The photo above shows a pool of water devoid of any plants in or around it other than algae, in the area of the Malakoff Diggins—California’s largest hydraulic mine. (Source. Following photos are also of Malakoff Diggins.)

diggins-creekSM.jpg

Source.

Minerals exposed by hydraulic mining can leach out and, if toxic, make plant growth impossible. Here is a view of what appears to be an exposed peak of some mineral:

majestic-cliffsSM.jpg

Source.
The steep slopes in themselves, of course, also resist plant growth.

Malakoff UCSB.jpg

Source.

As far as the differences in soil quality, comparing ground above the ancient riverbeds (which would probably be what’s on the top area of the cliffs shown) versus that exposed by water cannons like this

monitor-in-digginsSM.jpg

Source.

who can say? Are the bottoms of mining pits often more lushly vegetated because water collects there (as long as no toxic minerals accumulate)? Do different species, of different habits, grow in the pits as opposed to at the tops, and so growth appears different? My guess would be that it varies greatly according to specific location. Perhaps someone can point me to comparative photos or soil studies.

For the people downstream of these mines, the major consideration was what it did to their own locale. All the material washed away by the powerful streams of water—strong enough to hold a fifty-pound boulder in the air—went downstream sooner or later. Often the debris included boulders, cobbles, gravel, as well as finer material.

“The historian Hubert Howe Bancroft stated that an eight-inch Monitor [patented nozzle] could throw 185,000 cubic feet of water in an hour with a velocity of 150 feet per second.” (Source)

“A conservative estimate places the amount of debris dumped into tributaries of the Sacramento at 1.3 billion cubic yards.” (p. 132, article by Rohe in Green versus Gold previously cited). The total amount of material removed to build the Panama Canal (including both the French and the American work) was 268,000,000 cubic yards: only one-fifth the amount that was sent down the tributaries of the Sacramento.

The massive volume of debris that resulted from hydraulic mining clogged streams and rivers from the foothill outlets to the mouth of San Francisco Bay, obstructing navigable rivers and reducing their ability to carry flood waters. The lighter silt and sands, the “slickins”, spread over the river-side farms of the Sacramento Valley and ruined many farmers. These downstream impacts of the industry eventually brought on a series of local, then federal, lawsuits, and a series of debates in the California Legislature on how (or if) the problem would be solved. The end of debate came in 1884, when federal circuit judge Lorenzo Sawyer issued an injunction against the industry discharging its debris.

Source.

Many of the streams are turned out of their original channels, either directly for mining purposes, or in consequence of the great masses of soil and gravel that come down from the gold-washing above. Thousands of acres of fine land along their banks are ruined forever by the deposits of this character. A farmer may have his whole estate turned into a barren waste by a flood of sand and gravel from some hydraulic mining up stream; more, if a fine orchard or garden stands in the way of the working of a rich gulch or bank, orchard or garden must go. Then the tornout, dug- out, washed to pieces and then washed over side- hills, masses that have been or are being subjected to the hydraulics of the miners, are the very devil’s chaos indeed. The country is full of them among the mining districts of the Sierra Nevada, and they are truly a terrible blot upon the face of Nature. (Samuel Bowles, 1868.

It raised the level of rivers in some cases above the level of nearby towns, changed river-courses, silted up fish spawning gravels, reduced open water areas and increased tidal flats in San Francisco Bay and environs, and led to increasingly serious floods.

An invisible hazard accompanied the debris and silt-laden water: mercury. The gold-bearing material was sent down thousands of feet of sluices which were lined with mercury in order to snag particles of gold as they tumbled through. Mercury is very persistent in the environment. An estimated 2500 – 10,000 metric tons (2755 to 11,000 tons) entered the Bay. “Currently San Francisco Bay is listed under Clean Water Act Section 303(d) as impaired for mercury contamination, and many Bay-caught sport fish exceed the EPA human health criterion of 0.3 mg methylmercury/kg fish tissue” (Source). About 261 million cubic yards of sediment still remain in the northern part of San Francisco Bay.

When all is said and done

I went past the subject of the original commentator’s remarks (about seeing better vegetation in the bottoms of mining pits than on the presumably undisturbed top ground), to recapitulate some of the horrors of hydraulic mining, and that was not so I could bash him with matters not part of our differences, but because we must still fight against similarly great environmental damage from other mining practices. Strip mining, destruction of mountain tops, chemical “fracking” of strata to get at natural gas deposits, the list goes on and on.

Close to home, hydraulic mining’s little brother has come to visit. The recent moratorium on dredging in California has sent hundreds of miners with gas-powered dredges up to Southern Oregon, to suck up the banks and bottoms of streams in a small scale version of hydraulic mining. Small scale, but then our rivers and creeks are smaller too. The damage to the “stream banks and nursery gravels”, as one local gold panner wrote, is severe. “If you did a bio-survey of say, one cubic foot of stream gravel passed through a internal combustion driven pump, the numbers of ruptured organisms and caddis-fly eggs, water-beetle eggs, dragonfly larva, newt and salamander eggs would stagger one’s imagination. Just check a sluiced site for life forms sometime; see if you can find any. …The dredger’s assertion that their comparative damage is lesser than that of the major extractors doesn’t mitigate their injury.” (Pers. comm., Dan Barker, 2010).

A Pacific Tree Frog showing reddish temporary colors

Another post showed a Pacific Tree Frog (Pseudacris regilla) that had changed color, in 6 hours or so, from chocolate brown to tan. Today, in the same location—on our porch between the wall and a cardboard sixpack beer carrier—we found another (or maybe the same, who knows?) Pacific Tree Frog with distinct reddish color markings.

Frog, red markings IMG_7326.jpg

Here he is, shy fellow, looking out at me.

Frog, looking, red markings IMG_7326.jpg

This is the most common frog in our area, found from British Columbia to Northern California, and up to 11,000 feet in elevation. And they’re noted for color changing, “ranging from unicolor to mottled with greens, tans, reds, grays, browns, or blacks. They have the ability to change from light to dark”.

They’re in the “chorus frog” group.

During breeding season, males will call to attract females. A number of calling males is known as a chorus. A dominant male, or chorus master, leads off the calling which is then followed by subordinate males. If an intruding male comes instead, the Pacific Treefrog changes its usual two-part “ribbet” to a one-part encounter call. An observer trying to locate the Pacific Treefrog can mimic their calls and take over as chorus master, enticing the other frogs to begin calling as well. If this is done, be prepared to take on the responsibilities that come with being the chorus master!

I suppose they are the frog we hear so much in the spring, though I haven’t gone out to check; approaching calling frogs seems to make them be quiet, a very sensible move, so I haven’t pursued the matter. Great sound!

And their color changing is really intriguing.

There’s a rare blue morph,

Pacific Tree Frog, blue morph.jpg

Source.

and the more usual brown and green appearances,

Pacific Tree Frog, Wikimedia.jpg

and

Pacific Tree Frog, green.jpg

Source for both, Wikimedia Commons.

But the color-changing, apparently back and forth among all the colors except blue, is really intriguing. Wikipedia says, “Previously, it was thought that there were two different fixed colors that an adult tree frog could be. Now it has been found that some of them are able to change between the two.” The closer we look, the more complex things become. Wonderful!

Western Tiger Swallowtail butterfly, and a very close look at butterfly wing-color

We’ve gotten a few terrific photos of butterflies this year—some posted here and here— but none of the swallowtails has cooperated by alighting within range. When I saw one that had died and fallen to the road I carefully carried it home for the chance to get a close look.

Papilio 02 Dorsal.jpg

There are at least three very similar species of swallowtail around here—the Anise, Western Tiger, and Oregon Swallowtails. Based on the red and blue markings I’m thinking this is the Western Tiger Swallowtail, Papilio rutulus.

Finer than “frog hair”—butterfly hair!

Enlarging the macro photos shows details such as hairs on the body and along the inner edges of the wings.

Papilio40 CLOSE 1.jpg

These hairs, called tactile setae, are attached to nerve cells, which relay information about the hairs’ movement to the butterfly. … Adults have tactile setae on almost all of their body parts. In both adults and larvae [caterpillars], the setae play an important role in helping the butterfly sense the relative position of many body parts (e.g., where is the second segment of the thorax in relation to the third segment). This is especially important for flight, and there are several collections of specialized setae and nerves that help the adult sense wind, gravity, and the position of head, body, wings, legs, antennae, and other body parts. In monarchs, setae on the adult’s antennae sense both touch and smell. (from monarchwatch.com).

In the photo below, a ventral view of the lower wings where they meet at their lowest point, there is also a delicate fringe visible along the edges. This could have aerodynamic as well as sensory functions.

papilio 46 CLOSE.jpg

From pointillism to nanostructures

Parts of the markings that appear as solid areas to our eye are revealed to be pointillist creations. I suspect we would need to know much more than we do about the vision of butterflies (and their predators?), in order to understand how these markings work for them.

Papilio42 CLOSE 1.jpg

The odd squareness of the smallest dots of color is not some pixellation in the photo, but an accurate representation. It shows the shape of the overlapping scales which form the surface of butterfly wings. Here are some microphotographs of wing scales at various magnifications, from Wikipedia.

ButterflyWingScales.jpg

And here are color microphotographs showing the same squared-off dots along with the underlying scale pattern.

MicrophotographButterflyWingScales.jpg

Picture source.


It’s been known for some time that the colors of butterfly wings are partly from pigments but mostly from the microstructure of the scales, scattering light to produce the colors. Blues, greens, reds and iridescence are usually structural, while blacks and browns come from pigments. (Wikipedia).

But now we know more, and the more we know the more intricate and amazing it is. Research (published this past June) has been able to identify the light-scattering shapes from the wings of several butterfly species, and they are described as “ ’mind-bendingly weird’ three-dimensional curving structures… [resembling] a network of three-bladed boomerangs”. The name for these crystalline forms is gyroids, and they were first described

in 1970 by NASA physicist Alan Schoen in his theoretical search for ultra-light, ultra-strong materials for use in space. Gyroids have what’s known as an ‘infinitely connected triply periodic minimal surface’: for a given set of boundaries, they have the smallest possible surface area. The principle can be illustrated in soap film on a wireframe (see image below). Unlike soap film, however, the planes of a gyroid’s surface never intersect. As mathematicians showed in the decades following Schoen’s discovery, gyroids also contain no straight lines, and can never be divided into symmetrical parts. (source, text and soap-bubble photo: wiredscience.com)

Gyroid-like soap bubble.jpg

Gyroid-like soap bubble. Photo from wiredscience.com

So gyroids were introduced to humans as an imagined created form, something that is a mind-boggler for non-mathematicians to envision.

gyroid_hex.jpg

The image above is a mathematician’s representation of one of the simpler types of gyroid.

Materials scientists have learned how to make synthetic gyroids for photonic devices, such as solar cells and communication systems, that manipulate the flow of light.

gyroidProcess.jpg

A self-assembled solar cell begins with one of two polymers forming a “gyroid” shape while the other fills in the space around it. The inner polymer is dissolved away to create a mold that is filled with a conductor of electrons. The outer polymer is then burned away, the conductor is coated with a photosensitive dye, and finally the surrounding space is filled with a conductor of positive “holes”. A solar reaction takes place at all the interfaces throughout the material, and the interlocking gyroid structure efficiently carries away the current. (Source for image and caption, Cornell Univ.)

And when Yale evolutionary ornithologist Richard Prum got curious about exactly how butterfly wing-scales twisted light, he found gyroids. His team had to use an advanced microscopy technique with nanoscale resolution, called synchrotron small angle X-ray scattering, in order to see them, but there they were. (See note at end for citation of article in PNAS.)

The butterfly’s gyroids are made of chitin, not exactly the flashy material I would associate with iridescent wings. It’s

the tough starchy material that forms the exterior of insects and crustaceans. Chitin is usually deposited on the outer membranes of cells. The Yale team wanted to know how a cell can sculpt itself into this extraordinary form, which resembles a network of three-bladed boomerangs. They found that, essentially, the outer membranes of the butterfly wing scale cells grow and fold into the interior of the cells. The membranes then form a double gyroid—or two, mirror-image networks shaped by the outer and inner cell membranes. Double gyroids are easier to self assemble but they are not as good at scattering light as a single gyroids. Chitin is then deposited in the outer gyroid to create a single solid crystal. The cell then dies, leaving behind the crystal nanostructures on the butterfly wing.

“Like engineers, butterflies grow their optically efficient single gyroids through a series of steps that make this complex shape easier to achieve. Photonic engineers are using gyroid shapes to try to create more efficient solar cells and, by mimicking nature, may be able to produce more efficient optical devices as well,” Prum said. (Source)

In an interview about the work, Richard Prum said “We’re still trying to wrap our brains around gyroids and what they are.” The shapes seem to have evolved separately in several lineages of butterflies.

”It’s a Swiss cheese,” he adds, “with spiraling channels of air traveling through it that intersect one another. But those channels actually travel in three different dimensions through the cheese, and what you end up with is this very complicated form left behind, and that form is a gyroid.”

And while the idea of butterflies with Swiss cheese wings is slightly strange, Prum says it’s a very useful one for scientist and engineers looking for the next leap forward in electronic technology.

For example, Prum says, take the fiber-optic cables that carry phone calls under the ocean. These cables carry signals in the form of colored light, but it’s very difficult to insulate them well enough to prevent light from leaking out. Current transoceanic cables have to have booster stations built along them to keep the signal strong. But a layer of gyroids around the fiber-optic cable “would act like a perfect insulation to that fiber,” Prum says. The same tiny structures that give the Emerald-patched Cattleheart its lovely green patches could also be used to keep green light from escaping a fiber-optic cable.

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The vivid green color of the scales of this Papilionid butterfly are produced by optically efficient single gyroid photonic crystals. Caption and photo from www.physorg.com

Right now, it’s expensive and impractical to manufacture gyroids small enough to do that job. But butterflies hold the secret to growing them naturally. “If you could grow one, at exactly the right scale, as butterflies do,” says Prum, “you could make these things a lot easier.” (NPR interview, Jul 3, 2010)

This is a fine example of how curiosity can lead us to unexpected discoveries. The original question is one that could be used by certain Congressional anti-intellectuals in their periodic efforts to discredit basic research: “Imagine, all this work to find out what makes the color on butterfly wings! How ridiculous!” The research and technological developments that are thought “useful” by these folks had their origins in someone’s basic research, sparked by human curiosity. From butterfly wing-color to, perhaps, more efficient fiber-optic cables or solar energy collectors. It’s called bioengineering: investigating the functions and structures of nature, to derive principles and patterns for technological innovations. But for me it’s satisfying in itself, the revelation of these marvelous structures, underlying the evanescent beauty of a butterfly.

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Western Tiger Swallowtail butterfly on Buddleia bloom. Photo by terwilliger911, flickr.

Note: The article describing gyroids as the structure causing some colors in butterfly wings is:
Structure, function, and self-assembly of single network gyroid (I4132) photonic crystals in butterfly wing scales.
Vinodkumar Saranathan et al. Proceedings of the National Academy of Sciences. Published online before print June 14, 2010, doi: 10.1073/pnas.0909616107. The abstract is available free, but the article requires purchase or subscription to PNAS. There is a supplementary article here that contains some interesting images and very technical text. There’s even a movie you can watch showing a slice-by-slice trip through a certain sort of gyroid, or as the text says, though “the pentacontinuous volume of a level set core-shell double gyroid structure”.

Frog changes color with changed surroundings

I really wish I’d taken a photo of this frog when I found her this noon, sheltering on the porch next to the wall. There were some beer 6-pack carriers there waiting return to the store and when I picked one up there was this big dark frog clinging to the side. She (well, she just seems like a “she”) was a very dark brown tinged with green all over, with some darker mottling on her back, and sparkling gold stripes above her eyes. I caught her up and put her in our 100-gallon pond, on the lotus and water hyacinth leaves.

This afternoon, here she is, transformed in color.

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The dark splotches on her rear are about the color that her entire body was, about six hours ago.

It was only recently that I learned frogs could do this, so now having seen it in action I had to talk about it. Apparently it’s an ability found in many species, and the frogs can change as a result of light, humidity, surroundings, or “mood”. Whatever that means. The frog changed and the researcher cannot see any objective alteration in environment so it’s put down to “mood”.

Fear or excitement makes many frogs and toads turn pale, but others, like the African clawed frog, darken when disturbed. Another African frog is normally green, but turns white in the heat of the day to reflect heat and keep cool. The tiny African arum frog is ivory white and lives in the white blossoms of the arum swamp lily. When the blossoms die, the frogs turn brown to match. from exploratorium.edu.

We think she’s probably a Pacific Tree Frog (Pseudacris regilla).

[Etymological note: Pseudacris from the Greek pseudes (false) + akris (locust) — alluding to the frogs’ song?; regilla from the Latin regilla (regal, splendid) — probably referring to the markings.]