Suddenly, it's discovered that one of "Jesus's" arms on the Turin Shroud is dislocated. Now there's a surprise.

Man on the Turin Shroud (photographic negative): spot the dislocated right arm (your left)

Yes. The right arm of the Man on the TS is now declared to be too long (or maybe too short -   please, let's not quibble over details).  So it  must have been dislocated  from its joint with the shoulder. Any objections?  You have only a few seconds in which to voice your objections. No?  OK. So let's continue.

Links? Nope, can't be bothered. Most folk should know by now the internet site(s) that propagate this kind of stuff.  Why give them free publicity? Googling ' shroud of turin' will take you  there, if so inclined. But be warned. Repetitious tedium awaits you dear reader, to say nothing of obsessive tendencies. (And be warned - there be trolls as well, those that fake IDs so as to get in few ad hom insults before departing).

Biblical narrative? No sweat. The dislocation  must have happened while the founder of Christianity was carrying his cross to the site of execution.

Hold on a minute. I thought the shoulders of the Man on the TS had been  obliterated by those burn holes acquired in that 1532 fire, patched up some two or so years later by those industrious nuns. I thought there was no point looking for details of the region where arm meets shoulder.

Ah, well that's where you are wrong dear reader. There are those who can still discern original imagery under burn holes where we ordinary mortals give up in despair. It helps of course if one is a sindonologist, preferably employed by an Italian centre of excellence, so as to be able to spot these fine details. If you are just a retired science bod, as I am, lacking the magic eye, then simply don't bother. You are out of your league, my friend, amico mio.

Can this anatomical "I spy a dislocated shoulder"  be made to to fit the biblical account?  Why yes, no problem, none whatsoever,  It explains why that decent fella Simon of Cyrenia felt the need to step in so as as to relieve the condemned of his burden, having spotted the sudden loss of motor function in that over-burdened, indeed crippled shoulder joint.

Yes, it all adds up now, doesn't it?

Where would be be without the Turin Shroud to fill the gaps in the biblical account?

Alternative narrative? This blogger suggested many moons ago that the TS image was imprinted as a scorch onto linen by a medieval-era artisan from a heated life-sized bronze of the crucified Christ. But there was a problem. The arms of  the latter were still in crucifixion mode. They  needed to to be sawn off and re-positioned, hands over groin, to make the image look respectably post-mortem, modesty-protecting, those hands acting fig-leaf fashion  'down there' so as not to offend the ladies.

Crucified Christ? Maybe. Or there again, maybe a latter-day Templar knight, like, hint, hint, a falsely-condemned martyr  (Jacques de Molay? Geoffroi de Charney?), liquidated in Philip IV of France's purge of the order, involving initially the  lengthy imprisonment (7 years), spasmodic  torture and - finally - execution on a  Seine island in the centre of gay Paree by slow-roasting over coals in 1314.

If one's to be considered a scientist (as distinct from an agenda-driven apologist for the Christian faith - or at any rate one variant thereof) one cannot ignore alternative scenarios, least of all those that fit the radiocarbon dating (1260-1390).

My title ("Now there's a surprise"). What made our sindonologist friends suddenly discover a "dislocated arm at the shoulder"? Not by any chance the suggestion that one or both arms of an existing bronze template had been detached and re-positioned so as to make a more convincing template?

Afterthought. How many times have we read that this or other peculiarity of the TS image (missing parts, neck too small etc etc) is down to rigor mortis*, which may even have set in while the supposed victim was still nailed to a cross with outstretched arms. When asked how the same subject can still show rigor mortis  in the image on the shroud, yet have hands compactly placed over groin, we are airily told that the arms must have been forcibly wrenched into their new position. So why the talk now about dislocation, and a convenient 'Passion' narrative involving a slip on the road to Calvary with no mention of the older attempt to accommodate rigor mortis into story? Nothing betrays pseudo-science faster than an incoherent narrative that fails the test of internal consistency.

*  Example: see this (my bolding) from STURP's Robert Bucklin MD, JD, the preamble to his astonishing 'autopsy' on the man on the TS (I say "astonishing" given that  it is based on an "imprint" with no sure knowledge as to how the imprint was generated, or even whether the imprint was that from a real human being, dead or alive, as distinct from inanimate effigy):

"In the case of the image on the Shroud, it can be stated that the deceased person is and adult male measuring 71 inches from crown to heel and weighing an estimated 175 pounds. The body structure is anatomically normal, representing a well-developed and well-nourished individual with clearly identifiable head, trunk, and extremities. The body appears to be in a state of rigor mortis which is evidenced by an overall stiffness as well as specific alterations in the appearance of the lower extremities from the posterior aspect. The imprint of the right calf is much more distinct than that of the left indicating that at the time of death the left leg was rotated in such a way that the sole of the left foot rested on the ventral surface of the right foot with resultant slight flexion of the left knee. That position was maintained after rigor mortis had developed."

Update: 10 May, 14:25

I see that Robert Bucklin has been quoted elsewhere, apparently to suggest that the pathologist was quick to have spotted some lesions in the shoulder region:

“An interesting finding is noted over the shoulder blade area on the right and left sides. This consists of an abrasion or denuding of the skin surfaces, consistent with a heavy object, like a beam. Resting over the shoulder blades and producing a rubbing effect on the skin surfaces.”

 How can Bucklin have seen something suggestive of skin lesions when:

(a) the evidence for major wounds (lance in side, nails in wrist) and minor ones (scourge marks) rests entirely on blood stains (which could have been added, notwithstanding the less-than-conclusive 'blood first/image second' claims,  indeed mantra, with nothing that can be discerned as the site of a wound(s) in the basal body image per se, reinforced by the fact that: 

(b) there is in my view nothing in the fine structure of the TS image to permit a  distinction between hair and skin (surely one of the most neglected aspects of the image analysis). The identification of hair has been  done purely on the basis of "that's where one expects to see hair; thus any image density in that location must represent hair".


 If there is no distinguishing  between textures as different as hair and skin, then what price the likelihood of distinguishing between damaged and undamaged skin?

The fact that hair and skin are indistinguishable must surely rank as a priori evidence that the TS image was imprinted from a bronze template or similar.

I personally think Luigi Garlaschelli was correct when he suggested that the image of the head was not obtained by his 'rubbing' technique, as per torso, from a fully 3D subject, ie. student volunteer, (or, as I would prefer, scorch imprinting off an effigy), but from a bas relief, for reasons that can be discussed another time.

Yet another afterthought:  

Do you see clear, unequivocal evidence of shoulder-dislocation, dear reader? I've added some extra contrast to the Durante 2002/ShroudScope image in an attempt to make your task easier.

I don't, unless I make what I consider a somewhat arbitrary decision as to where to draw a line that delineates image from non-image area (not easy when the background is also a sepia colour, same as image but of lower intensity AND the encroaching scorch marks from the 1532 fire).

Were it a photograph, one would say it was the subject's right shoulder that was the lower of the two. But it's an imprint (think of it as left by a face-down-into-linen operation) so it's the subject's left shoulder that is lower.. BUT IT'S SAID TO BE THE RIGHT SHOULDER THAT IS LOWER THAN THE LEFT!

Are the "dislocationists" assuming image cut-off where I have added some yellow dashes )? If so, methinks that's an arbitrary decision too far.... Might some folk being seeing what they want to see?

Here's the corresponding dorsal views:

And here next is where the 'dislocationists' are presumably making the separation between image and non-image:

This time, think of an imprint being taken from a back-down-into-linen subject, with face poiting outwards. It's the subject's right shouder that is lower. (!)

Er, Houston, we have a problem. It's the subject's left shoulder that is lower in the frontal view, if one takes account of the 'sense' of imprinting.  But it's the right shoulder that is lower in the dorsal view.

And where's the evidence for some kind of lesion affecting one shoulder and not the other?


My position, leaving aside that tiny anomaly and/or lack of indisputable detail: if you don't know for certain precisely how the image was imprinted, and from whom or what, then you have no secure basis on which to go drawing anatomical or injury-related conclusions. One cannot base major anatomical conclusions purely on some apparent asymmetry in the Shroud image around its midline. Other corroborating evidence is needed.

Amazing! Bacteria have been cajoled into accepting two new letters into their genetic code! But what are those letters - in chemical terms?

Yes, there's an exciting item of science news this morning - the best I've seen in months. I shan't try to write a lengthy preamble, there being no need, given that there are journos out there who have done a reasonable job already (and get paid for it!)

See for instance this write-up in the Independent.

New Life: Scientists create first semi-synthetic organism with alien DNA

But it's very frustrating to have new chemicals referred to by abbreviations, without knowing what the letters stand for, or being given structural chemical formulae.

The two new bases in  question, shortlisted from scores of experimental candidate molecules, screened over many years of study, are "d5SICS "  and  " dNaM ".

While I haven't got a fix on the names (but could make an educated guess) I have discovered a highly detailed paper on their chemistry that gives structural formulae.

The graphic above shows the two new letters and their abbreviations  (d5SICS and dNaM). They have been shown  above as the base-pair, capable of providing a third type of rung on the DNA double helix, additional to Mother Nature's G-C and A-T base pairs and two new letters in the genetic code, making 6 instead of the present 4.

If you know a little chemistry, you should be able to spot features in both the new bases that show they are alien to Planet Earth. The first (d5SICS) has a sulphur atom attached to the ring system instead of oxygen. What's more, one of the two rings in that cyclic structure lacks nitrogen - it's a benzene ring - whereas the authentic purine bases like adenine and guanine have nitrogen atoms in both rings. The second (dNAM) lacks nitrogen in both those rings, which are simply two fused benzene rings, i.e. naphthalene.

I'll add structures of authentic adenine and cytosine for comparison here later.

So, these very clever and, by all accounts, dedicated scientists, have been able to create entirely new base pairs that mimic the real thing, and which have all kinds of potential for engineering new life forms (yes, they have considered safety aspects and have a strong case for thinking that any new organism would not be able to escape from the lab and multiply, unless accompanied by a personal chef  doling out daily supplements of the new exotic bases).

What I find particularly fascinating from a quick read is that the two new bases form a base-pair in DNA ( a "rung" of the ladder) without needing to form hydrogen bonds with each other. Those familiar with DNA lore  - or who have read  James Watson's "The Double Helix" - will know the importance that was attached to H-bonding between DNA base pairs in the model-building that finally yielded the elegant and stable helical structure (pyrimidine AT-base pairs forming two hydrogen bonds, purine C-G base pairs forming three). The new "X-Y" base pair (for want of a better term) is essentially proclaiming - "Look, no hands!".

Oh, and both partners resemble "two-fused ring" purines, whereas the AT and CG base pairs are one purine-one pyrimidine, which is two-fused ring to single ring only. More later when I've had time to pore over these new bases, and maybe find their full chemical names.

In fact (late addition) yesterday's splendid article in Chemistry Today shows that the new exotic bases pair up by an entirely different mechanism - hydrophobic bonding (which relies purely on the ubiquitous albeit weak interaction between molecules known as Van der Waal forces ("flickering dipoles"). Standard hydrogen-bonding (dashed lines) is shown below for reference.

Here's a link to the New Scientist write-up. 

Update: My comment just this minute posted to the Guardian:

The systematic name of d5SICS, obtained from the chemical's supplier (Berry Associates, no relation) is as follows:

2-((2R,4R,5R)-tetrahydro-4-hydroxy-5-(hydroxymethyl)furan-2-yl)-6-methylisoquinoline-1(2H) -thione

That gives no clue as to how d5SICS was arrived at,  though undoubtedly an abbreviation of the much shorter 'trivial' name.  The "S" may refer to sulphur, aka sulfur, which in the systematic name is "thione".

See also greenfluorescentblog (there's someone else who, in common with me, seems frustrated not knowing what the letters stand for).


We live in interesting times...

Whether this breakthrough has immediate prospects of practical spin-off (new drugs etc) remains to be seen. There are grounds for thinking otherwise. But what it shows clearly is that the evolution of life on Earth, and probably elsewhere  in the Universe, did not depend on the chance supply and utilization of 4 highly specific nucleic acids, capable of self-assembling into a double-helix. The fact that these two novel bases, ones that do not even have the wherewithal to form hydrogen bonds between base-pairs, suggests that the chemistry is not quite as critical as might previosly have been thought, and indeed raises the probability of there being extraterrestrial life, maybe based on nucleic and DNA-like double helices. It could be a different type of base, or bases, and possibly involve more than 4 (though 4 is more than sufficient to code for our 20 or so essential amino acids that are adequate to create the amazing biodiversity that we see on our amazing blue planet (and that's not counting the 98% of species that once thrived and which through climate change, asteroid impacts etc are now extinct).

Why our 4 particular nucleic acids? That was a topic I addressed on this site well over 4 years ago.

Did you know that phonetics-enabled Google Translate provides a means for acquiring new languages effortlessly and SCIENTIFICALLY?

OK, so you want to acquire the rudiments of a new language, and you want to do it fast, efficiently and at your own laptop whenever you have a few minutes to spare.

It can be done, as I discovered just yesterday. What's more, it can be done for most of the common languages (shame if you want to learn Georgian - as I do for a planned trip to Tblisi later this year - but as I say, the more common languages, from Swedish to Japanese).

How's it possible?

Here's how (apologies to those who knew about it already).

First, use the internet to find a newspaper in the language of interest. You can enter 'newspapers france' into Google search for example, and then click on one of the links provided.

Here's a screen grab of today's L'Humanité for example. (Chosen for its colorful blog-friendly front page I hasten to add - forget the paper's links with the ultra-lefty French politics).

Find an article with some recognizable current news with which you are familiar. It might be "Ukraine" for example, or the recognizable equivalent in your chosen language. This being a science site, I scanned for a non-subscription article that had "antibiotiques" in the title.

Then copy and paste a chunk of text into Google Translate. 

 Here's the chunk selected:

Use the left and right selectors to set the language entered and the translation required. The URL for the above link to Google Translate is:

https://translate.google.com/#fr/en/

That shows it's set to translate French into English.

Now click the Translate key to get a near instant translation.

(Click to enlarge).   Note the audio key for a phonetic version (my yellow circles) which I consider gives a very passable pronunciation, and one moreover that is not entirely machine-generated (native speakers must presumably have been recruited  to recite every single word in their own particular language, which amazingly can be strung together in different orders while still sounding like real speech).

UPDATE 8th May. NO! THAT'S NOT HOW  THE VOICE-OVER WAS DONE! IT DID NOT REQUIRE READING EVERY WORD IN THE DICTIONARY INTO A RECORDING DEVICE. IT'S ENTIRELY PHONETIC, BASED ON THE PHONICS (THE SOUNDS OF CONSONANTS AND VOWELS). HOW DO I KNOW? BECAUSE I ENTERED SOME FRENCH INTO GOOGLE TRANSLATE A FEW MINUTES AGO THAT WAS STILL SET TO RECEIVE ENGLISH, AND THE LADY PROCEEDED TO READ OUT THE FRENCH AS IF IT WERE A PAGE OF ENGLISH. HILARIOUS!

 
No, it's a a machine translation, needless to say, but is usually good enough to get the sense of a passage.

The real joy is the discovery by this blogger of the additional keys at the end of the two texts of a phonetic pronunciation in each of the two languages. I have circled them in yellow.


So one has a triple whammy here - the foreign text,  an instant translation alongside, and an impression of a  native reading the foreign text. Again, the latter's not perfect, especially where one sentence ends and another starts, but it's still remarkably good in my opinion.

How long's this 3-in-1 facility been available I wonder, and how come it's not been generally fanfared? It certainly wasn't some years ago when I was struggling to acquire and perfect foreign languages, even the most common like French, German, Spanish and Italian.

I have to say it's doing wonders for my foreign languages, and it's fun to take a particular passage and hear it being recited in all the major world languages, while attempting to follow (for me) the foreign text.

What an amazing species we are, to have developed a proliferation of languages, all different, yet which work so effectively in each of their different regions. Which member(s) of the tribe or clan decided what new word to give common items originally, like love, hate, thunder, lightning, dog poo? Or did they sit round  a table and cast votes? What were they drinking (or smoking) when any number of 'memorable' English place names. villages especially, were chosen?

Would it be too much of an exaggeration to claim that the 3-in-1 package offered by Google is as close as one is likely to come with present technology (short of the homogenized one-size-fits-all audio-visual software packages) to SCIENTIFIC language acquisition? One is able, after all, to EXPERIMENT, by taking current affairs materials that are of interest to one, instead of pre-written software. One can change a word here or there and see what effect it has on the translation.

The Achilles heel, needless to say, are those machine translations that can still be painful to read. But there's a way of tweaking those, as I discovered a while ago. Take the offered translation, and see what you get by way of back-translation. If it's different, then try simplifying the text until the original and translation are faithful to each other.

Oh, and one other thing. Don't expect to get a complete audio version from very long passages. The "voice" may stop before the end. I suspect it's something to do with real-time bandwidth control on the part of Google, rather than being subject to a personal ration, since repeated hitting of the audio key can often get it to resume where it left off. If that doesn't work, then try deleting everything up to the stop point, and then rehit the audio key, a few times if necessary.

Happy exploration! 

Oh, and here's something else that's amazing. One can copy the URL for any particular page of  translation, and SAVE or even email, then paste it back to resume where on left off.

Here's what the URL looks like for what you see above (Yes it's long, because it contains every single word on the page!)

https://translate.google.com/#fr/en/L%E2%80%99OMS%20vient%20de%20publier%20un%20rapport%20mondial%2C%20alarmant%2C%20sur%20les%20cons%C3%A9quences%20de%20la%20r%C3%A9sistance%20aux%20antibiotiques.%20Devenu%20inefficace%20chez%20certaines%20personnes%2C%20l%E2%80%99usage%20inappropri%C3%A9%20des%20antibiotiques%20est%2C%20aujourd etc etc etc etc etc etc etc etc etc etc

 

Here it is as a single hotlink . That's if you want to see and hear for yourself  the amazing versatility, to say nothing of educational value, of  the Google Translate facility. Go to that chosen  L'Humanité page, click on the audio tab at the bottom right.  Be prepared to be pleasantly surprised by the quality of the lady's spoken French. Just ignore one or two strange inflections now and again.

Further reading: try entering 'google translate learn language' into your favourite search engine.

Or click here:  google translate learn language

For those like me, still grappling with fast-spoken French, here's another tip. Log onto the France Info radio station home page. There you can listen to the radio direct if you wish. But what I do is select one or more pre-broadcast items from the list (daily, or listings that go back some 2 months). You can listen to the broadcast first, often including interviews. But here's the chief advantage. Look at the end of each summary for the (black font ) link labelled 'detail' and it gives you an independent write-up, providing an overview of the broadcast, which you can then cut-and-paste in Google Translate and "Google Speak".One can then listen to a particular topic over and over again, either retrospective 'live'-broadcast or accompanying summary, preferably both, at the end of which you can expect to have a pretty good grasp of both vocabulary and pronunciations.

What message do Photinia leaves – shiny as well as red – send to opportunist grazers? Eat me at your peril?

Sorry: hit Publish button prematurely by mistake (easy thing to do with Blogger layout). Already listed under Google!  In need of editing for typos etc

It's probably not just the scarlet colour of Photinia spring foliage that warns off herbivores. It's probably that aggressive-looking glint too...

Botanical note: it's Photinia x fraseri that's under the spotlight. That's Fraser's Photinia, aka Photinia Red Robin in the UK, and, I believe, Photinia Red Tip in the States ,that being where the hybrid was first spotted in Alabama (see later).

More on the botany (and evolution) later, like the Far Eastern origin (China and Japan)  of the two contributing species that came somehow to make a cross.


So what you may ask caused this science bod to get focused on this particular plant, given the gardens here and in Switzerland (from which I've just returned) are bursting with the colour of scores of Spring flowering shrubs and bedding plants?

The clue is there already: Switzerland. The Swiss have gone for Photinia in a big way - not just as a stand-alone shrub, but for hedging purposes too.



There were still more gardens sporting Photinia on the approach to this village:

Here's another taken nearby, still lacking sunshine on those amazing leaves.

These pictures, under cloudy skies, hardly do justice to Photinia and its descriptive name (more later).


Here's one I took from a moving bus at our small village on the south-facing vine-terraces  above Lake Geneva.  (We ate at this excellent restaurant on our first night; the local rose wine is superb too - with for me the obligatory good 'bite'). Spot the botanical street furniture.

Here's an archive picture that does it justice: luscious sun-kissed Photinia.

Note below  the clever two-tone effect that can be achieved with clipping, which relies on the fact that  the red leaves are new Spring growth on the previous year's foliage (Photinia is an evergreen, contributing no doubt to its popularity)

(someone else's picture from image archives)

.At least I think it's done by selective clipping (but on second thoughts someone may have used a mix of two different shrubs). Either way it's Fun Photinia.

So then, what about the science?

Perhaps not surprisingly it's the red colour of the spring foliage that attracts all the attention. So let's insert a brief word about that to get it out the way, not because it's uninteresting, far from it, but because it distracts from the interesting etymology of Photinia (a word that gives no clue to colour). 

The red colour is due to a class of plant pigments that is ubiquitous throughout the entire plant kingdom - from algae to autumn leaves - and which has been the subject of much puzzlement. I refer to the anthocyanins.

Anthocyananins are flavonoid compounds whose aromatic polycyclic molecules bristle with phenolic -OH groups. Why are they there, in so many different species and habitats, often with no obvious explanation?

For those interested in pursuing that question, I would recommend a short and concise review with a highly apt title:

Nature's Swiss Army Knife: The Diverse Protective Roles of Anthocyanins in Leaves

by Kevin Gould

Here's the Abstract (but I recommend the rest too).

Anthocyanins, the pigments responsible for spectacular displays of vermilion in the leaves of deciduous trees, have long been considered an extravagant waste of a plant's resources. Contemporary research, in contrast, has begun to show that the pigments can significantly influence the way a leaf responds to environmental stress. Anthocyanins have been implicated in tolerance to stressors as diverse as drought, UV-B, and heavy metals, as well as resistance to herbivores and pathogens. By absorbing high-energy quanta, anthocyanic cell vacuoles both protect chloroplasts from the photoinhibitory and photooxidative effects of strong light, and prevent the catabolism of photolabile defence compounds. Anthocyanins also mitigate photooxidative injury in leaves by efficiently scavenging free radicals and reactive oxygen species. Far from being a useless by-product of the flavonoid pathway, these red pigments may in some instances be critical for plant survival.


I've bolded up three words, for reasons that will become clear later when one considers the presence in Photinia leaves of toxic chemical compounds (toxic to grazing animals that is).

In fact, of the reasons listed for the presence of red anthocyanins. none except arguably that warning to visual "eat-me-at-your peril" sign to herbivores is self-evident. While I have no doubt that the anthocyanins absorb harmful UV-B rays, they don't need to be coloured to do that, colour being a characteristic of absorption in the visible spectrum - red pigment abstracting green and yellow light. Lots of completely colorless substances are capable ot absorbing uv (like those in sunscreen lotions that come out the bottle white - fortunately not bright red, the aim being to avoid that coloration).

Why my preference for the idea that the red anthocyanins are a warning to herbivores?

The striking visibility of Photinia from afar is not just the red colour of those leaves, is it? It's their glossy reflective character. In fact, if one looks at photos of Photinia in full sun, one finds that a sizeable proportion of the leaves are not red, but "white". As hinted at earlier, the very name "Photinia" is not a reference to red colour, or indeed any colour, but to "light", Gk: photos.


 From googling:

The botanical genus name derives from the Greek word photeinos for shiny and refers to the often glossy leaves.


 Photinia leaves have an unusual degree of shininess, even indoors under artificial light.

Is it seen simply as red from a herbivore's eye perspective?

Shininess - the property of being shiny. So what's that about? Why are some things, like metal surfaces, glass etc shiny, while others are matt and dull?

A more scientific term than "shiny" would be "reflective", inasmuch as it gives a clue as to mechanism. "Reflective" in turn brings to mind everyday mirrors, but that can be a step too far, given that mirrors are glass plus a reverse-side coating ("silvering"), whereas we know that plain glass is also capable of reflecting light (shop windows etc).

If one reads up on the subject, as I have just done (briefly!), all is explained. First, while reflection is most efficient off a metallic surface, like the silvering of a mirror, it is not essential to have metal (which Photinia leaves lack). All that's required is an interface between two layers that differ in their refractive index, explaining why air/glass can act as a mirror, and by extension, the interface between air and the waxes and cutins of leaves. That's the physics, basically, but there's chemistry too, or at any rate physical chemistry to be grasped, when one learns that reflection is not a mere passive process, but actively involves the atoms of the reflecting surface, more specifically the electron clouds, provided the latter are of the right kind. To cut a long story short, the incident light produces changes in the electron clouds (polarization etc) and the energised atoms each  become point sources of light, re-radiating light as if a new light source, and doing so (obviously) in conformity with the laws of reflection (angle between normal and reflected ray = angle between normal and incident ray).

But it's not events at that level that are my chief interest where Photinia is concerned, which could be said to apply to any reflected light. We are not talking about any old reflected light. We are talking about the way that Photinia leaves glint in the sunshine in a manner that distinguishes the shrub from other ones, red ones included, such that a Photinia can be spotted at 100 metres or more. Glinting? What's that about? It's obviously to do with reflection, but special reflection.

Yes, there'e ordinary reflection and there's special reflection . The first is non-dazzling, the second is, wait for it, dazzling, if only slightly.  Here's an example of the first, non-dazzling reflection, encountered on my recent travels:

Vaud canton, Switzerland near Lake Geneva, April 2014. Shame about the absence of sunshine that day (one tanned instantly the preceding day).

 Here's a more striking example - Mirror  Lake, Oregon - but still "ordinary reflection" for present purposes.

 

Sun reflected in a signal mirror (archive picture)

What you see above is what i call here "special reflection". It requires a specific geometry.

Special reflection is the beaming into the eye not of a sun-illuminated object, but an image of the sun itself. It's "just" an image, and a virtual one at that (can't be captured from a plane mirror onto a screen or photographic film) but id every bit as bright and dazzling as the real thing.Thus the use of a mirror to capture attention, sometimes at considerable distance.

Here's  the geometry set out in a survivalist guide to attract attention of an aircraft. A signal mirror is being deployed (hole in centre to assist with sighting and alignment).

The mirror in the above diagram needs to be correctly oriented in two dimensions. It has to be tilted upwards towards space and have the correct orientation in a horizontal plane, level with the horizon, for refelected light to reach the chosen target (a passing aircraft). In practice of course one does a lateral sweep such that the intended observer receives flashes of light (spotted more readily than a fixed beam). What's the relevance to those glossy Photinia leaves? The answer should be, er, glaringly obvious. Photinia has to be smart in the way it orients its stalks and leaves if it is to function as a deterrent to grazing animals that can have an angle of approach on a radius that sweeps 360 degrees of arc. The question is therefore: ARE Photinia plants designed to "glint" a 'hazard warning' at herbivores no matter what the angle of approach?

But Photinia is not trying to catch the attention of high flying aircraft, but ground-grazing herbivores. How can ot do that most effectively? is it by "ordinary" or "special reflection"?  You can probably guess what's coming, and yes, it's to do with the sun acting not merely to illuminate everything  on which it falls, but as an incandescent orb in the sky that can be projected as a virtual image from ground level mirrors - the latter including those glossy Photinia leaves - into the eyes of herbivores. Would the abiility of leaves to act as tilted mirrors be left to chance, or would there be evidence of specific adaptation for that purpose?

Here's a telling passage gleaned from a plantsman's catalogue (my bolding):

“Bright red, glossy new foliage makes Photinia x fraseri Red Robin one of our top 10 hedging plants. Older foliage is dark green with red tinges and flowers creamy white in spring although this species is primarily grown for its foliage colour. The growth is somewhat loose and gives good movement in the wind.”

Others too have commented on "loose" growth in a variety of terms, which one suspects is a euphemism for "a bit untidy looking, not the correct choice if what you are seeking is a geometrically-precise box hedge".

Here's an archive picture that taken with the above helps build the case for what I'm about to suggest:note the sizeable proportion of 'mirror-like' leaves that reflect the sky and (probably) in some cases the sun itself (even if a discernible image of the sun is not visible, merely hinted at)?

OK. let's return to the mainstream first - with the attention focused on those bright red leaves. Theories abound. Some say they are a protection against damaging radiation which, as indicated, hardly squares with visible colour. Others suggest that herbivores that grazed on Photinia in its natural habitat were colour-blind to red, so would have ignored red leaves. Maybe, but where's the hard evidence?

There's another explanation - to do with the presence in Photinia leaves of cyanogenic glycosides. They are protective chemicals that aren't just feeder-unfriendly re taste. As the name implies, they release hydrogen cyanide (HCN) in the gut, especially of ruminants with multiple stomachs that nibble foliage on an industrial scale. HCN, the stuff of execution gas chambers, blocks respiration at the cellular level, producing the mother of all bad turns, the kind that is usuaally described in  medical and no doubt veterinary jargon as death.

But maybe Photinia has adopted a belt-and-braces approach, reasoning (if plants under evolutionary pressure, to say nothing of personal survival when there is no fight or flight mechanism) can be said to reason, that red color in the leaves is not a sufficien t defence. After all, there are any number of plants with red leaves, notably in autumn, but in spring and summer too.

So maybe Photinia adopted an extra defence in the form of shiny leaves. How would that work in practice? i guess one could take a leaf from the "colour is bad news" school of thought, and suggest that anything unusual about appearance, whether colour or shininess, aids survival if there's a toxin present. Or it could be a lethal one that simply wipes out grazers with a genetic predisposion to prefer red over green, say. Or it could work more subtly, and simply give the grazer a bad headache, such that it forms an association ("red is bad" or "shiny is bad" so the initial bad experience is less likely to be repeated.

One is hesitatnt to dismiss any "evolutionary" kind of hypothesis that works slowly, maybe through countless generations, slowly modifying the gene pool to shift the odds in favour of survival. So if shininess is added to leaf colour as a deterrent to feeding it might well operate by that same mechanism of simply conferring a "difference" that in time is perceived as a threat to survival. One cannot help but wonder if there's not a more immediate warning that comes with shiny leaves that glint in the sun, especially when the wind blows. foliage becomes agitated. 

What are the natural enemies of herbivores, excepting toxin-laden plants. Carnivores, obviously.How is the approach of carnivores detected? Hearing and small, obviously. What if the wind is blowing, and both hearing and small are compromised? what is the last line of defence, especially against a stalking predator? Answer - sight. And which part of the anatomy is the hardest for a predator tpo conceal if sneaking up, keeping low to the ground?

Answer - the eyes, the light-reflecting eyes. Eyes glint.

 Might a Photinia shrub, with its glinting leaves, maybe shifting in the wind, given the "growth that is somewhat loose" make grazing animals nervous of approaching too closely? Is it too much of a distraction, masking the presence of 'real eyes'?

Natural habitat? Tricky, since given that the common-or-garden Photinia x fraseri reported to be  a cross between two species. Viz:

History: Photinia x fraseri is a hybrid cross of Chinese native, Photinia serratifolia (syn=Photinia serrulata) and the Japanese native, Photinia glabra. It was discovered in a seed lot at Fraser's Nurseries in Alabama ca. 1940. (Dirr).The red tip (P. x fraseri) is a hybrid. It resembles a supersized version of one of its parents, the Japanese photinia (P. glabra) which is smaller in stature and leaf size. 

Given the somewhat mysterious circumstances by which the hybrid came to be discovered, apparently as an accident of  nature(?) or maybe nurture of two separate species in close proximity(?), close enought to allow cross-pollination and fertile seed-production:  

Why  is that?

Sorry about the scrappy ending - down to that poorly-sited Publish key that is so easy to hit accidentally.

The order of tabs should arguably be changed to SAVE, PREVIEW, PUBLISH, CLOSE. Certainly SAVE (in draft) should be well-separated from PUBLISH.


I'll tidy things up in a day or two (busy right now). The hypothesis being proposed here is that the somewhat open 'untidy' look about Photinia (the smaller specimens especially that are still getting established) is perhaps no accident - it's the result of leaves and stems being oriented generally upwards but through a wide range of angles to ensure that a sizeable proportion of leaves are always reflecting the sun towards an approaching herbivore, thus flashing a warning signal so to speak: this plant is a threat to your health and wellbeing.