Tuesday, May 26, 2009
I Knew It!
Funny thing the way the mind works. Or is it the soul, stretched taught between the brain, and some strange dimension, timeless and unreadable to the living, but as vast as the certainty one feels about a great blue vaulted sky. Can you feel that? You know things sometimes not by looking at them and thinking, "This is a..." But rather, simply seeing, feeling, and knowing. You might complement such knowing with a curiosity, and then travel some roads of inquiry. Or not. Knowing can sate the heart and mind in one instance, and fill one's life with an insatiable desire the next. You've seen a leaf, after winter, its substance falling to shreds, and its veins, or vascular system, left over. I believe you have seen such a thing and just on the evidence of its beauty known something that almost can't be articulated. You might say the beauty of the leaf is in the novelty of its recognizable form. Recognizable but so different, just as my circulatory system, alone, and stripped of the rest of me, would look like me. There is also the mystery of what endures, and what does not. The bleached bones of the canine I found in a ditch on the highway spoke glancingly on the the essence of dog. What was missing was more than the bark. The expressive flesh of the animal twitching, and waiting, and wanting chase. The quiet, and stillness of the bones were not echoes of death to me, but stark contrast to the experience that "dog" means. And the bones were so very very beautiful. More beautiful to me, in some ways, then the dog. Though, I couldn't say I ever met the dog, as I'm sure the circumstances we found ourselves in that day, spell so well. But heres the thing. I have known something too, my whole life, about that leaf. It's flesh all gone, but its veins a net stretching to the limits of its species habit. It being my way, I have wondered about that leaf in the language that my creative side seems to crave. Just staring and staring. Just the posture of my gaze. Perhaps, somehow, it was not the leaf, but the feeling in the shape of my body as I sagged in a physical contemplation, upon encountering that net of veins. I was reading about lignin (as should not surprise you) and it hadn't really occurred to me, but this book was explaining that a plant requires in it's growth various things. Pretty obvious, don't we all. So it went on touching on the components of a cell wall, and how that cell wall needs to be able to absorb and purge water, so as not to have it's PH get wacky and muss up the rather astonishing chemistry that weeds aren't often credited by normal folks for performing. Sorry weeds. Good Job. So cell walls should be permeable (pretty much throughout all organisms, that seems to be the case.) That's good. Then the book discussed the structural needs of a plant, and advantages, and disadvantages enjoyed by various strategies employed by vascular plants. One way or another, a plant is going to seek uprightness (most of 'em) and to remain whole and undivided (all of them, though as gardeners know, above a certain limit, division doesn't kill certain plants.) Those two requirements require cellulose, hemicellulose, and lignin. All of them polymers. The first two are made of sugar. And lignin is made of alcohol. Why? Of course the alcohol is for all practical purposes made of sugar (in the cycle that produces it) but then again, all this stuff is made of CO2, and water, so what gives? None the less it is useful, should it be driving you crazy, to ask the question and wonder a bit about that list of polymers. They are after all the most abundant biological polymers on Earth (there is an order of magnitude more cellular material in bacteria in all the nooks and crannies of the globe and oceans, then there is plant "biomass". None the less, there is a mind mindboggling amount of cellulose and hemicellulose and lignin.) As the book was careful to point out (that apparently being its purpose in life) the structural needs of the plant are carried by all three polymers, but enforced by lignin. Lignin is simply enormously strong, as anyone who has left a one year old maple sapling in their yard over winter should discover when it comes time to pull it, or snap it, or thrash at it in desperation. That thin green plant flesh becomes something rather different when it goes "woody." Of course not all plants do. But all plants none the less need lignin. Why? The book explained that it comes down to the original thing that lignin evolved for. It wasn't it's stupendous strength, it is thought by people who look into these things, that lignin developed for. It was its fear of water. Hydrophobia. That's why I brought up the cells permeable walls earlier. Plants, it turns out, just like any complex system, need some permeable barriers, some semipermeable barriers, and some completely impermeable barriers. It's sorta hard to get a few drops of water evenly distributed through a sponge, to say nothing of the soap you dissolve in that water. To completely saturate a hydrophilic substance, you need a fair amount of water, and you need to be extremely chilled out about the rate at which that water permeates the substance, and the stuff that water may or may not distribute throughout your "sponge." As plants were developing from their single cellular origins they in all likelihood encountered this problem of a plant cell's inherent water love. One cell has no way outside of the dictates of its own survival and it's probable programming to share what wealth there is to share, to help distribute nutrients and water to the far off regions of a blob of unvascularized plant. A highway or road, or pipe if you will, for water was needed for the plant to provide all of its cells a gentle bath of H20 and nutrients. But what would you make such a pipe out of? Plants are mostly cellulose, as the word surely hints at in it's name. Cellulose is really a kind of jelly that is made and laid down in a sort of composite manner by plants (many aspects of organism physiology have this "composite" approach. Your teeth are made within your gums by your body laying down a protein net, then slowly secreting onto that net chemical attracted to the protein, which then folds itself and catalyzes the chemical into the mineralized product you and I call tooth. This vast simplification of the process was a marvelous thing for me to learn, and is an example of composite structure in the natural world of my mouth. It is similar, those vastly more complex, to the manufacture of fiberglass or carbon fiber, both composites themselves. Look to biology to one day be manufacturing all those materials, better and with zero VOC's. Another thing, that protein matrix your body lays down for your teeth to mineralize around is what you smell "burning" when you get your teeth drilled. Yikes!) So cellulose is a sort of woven composite in plants, by which they get their bulk to a great extent. And as anyone who ever cut a tree down knows, cellulose likes its water a great deal. Lots and lots of water. But, cellulose could at best only make a soaker hose. And what water it wicks it wicks entirely dictated by salinity, osmotic pressure. Which isn't always taking the plants water where it needs to go. This is why lignin came along. Plants developed lignin (it is thought) as a water repelling substance that the chemistry of a plant could produce, and that when it made a tube, water could travel heedless of the thirsty cellulose surrounding the tube of lignin. These tubes of lignin could stretch to every cell in the plant, and such vascularization gave rise to all manner of unexpected gifts in the plant world. As the plant matured year after year it left ring after ring of lignin pipes around itself, and a funny thing started to happen: the plants stopped falling down in winter. Or during the dry season. Some plants just kept growing ring after ring after ring and before long, all those tubes, with cellulose cells dried out and dead between them amounted to something we human beings would never have gotten where we are (or lived the lives we live) without: WOOD! So lignin, along with the increase in the amount of oxygen in the atmosphere, provided plants an entirely new habitat of of the breezy skies. And entirely novel lifespans for organisms, sometimes reaching 1000 years, for a single set of DNA. Go ahead and try that yourself. By the way, it is worth mentioning here that I am going to write some time about what I learned three years ago when I took some time to study a Biology textbook my cousin Dr. Heather Greist gave me. One of the secrets of long life in trees is their incredibly slow metabolism, despite their enormously large output of work. Such a circumstance seems a contradiction until you look at how plants TRANSPIRE, or draw water from their roots to their leaves and straight out into the atmosphere. I'll give you a hint: a tree may conservatively pull six hundred gallons of water through its roots every couple of hours, and breathe out all that moisture on a hot, sunny "humid" day.That's 4800 pounds of weight atomized into the atmosphere. Try it some time, you will fail in ten days to achieve that with the solemnity of a tree. But the tree doesn't pump the water itself at all. It transpires it. And I didn't know what that was until 2006. One of my dreams is to make a gigantic Gym sized model of a leaf's stomata (air sack which regulates this tendency to transpire or not by opening and closing pores on the underside of a leaf.) The idea that ten year olds could be walking around with this profound appreciation of how tricked out plants are, just fills me with so much pleasure. But the truth is, you knew all this before. All this lignin and cellulose stuff. Just by looking at that leaf. You knew that some of the leaf was gone, the soft and chewy and moist food of the leaf. The sort of meal the toothless require. And you knew what was left, like the bones of a dead canine, was enduring, and continued long after death to speak of the nature of it's parents species. The shape of the Maple leaf remained, in a cascading set of subtle branches. From the visible down to smaller than visible with your eye, the leaf sat there before you, like the horizon six inches square. Beckoning not toward reckoning but whispering with the confident look of a beaming child: this is the reason I am.