Pierre‐Henri Gouyon
Transcription
Pierre‐Henri Gouyon
Evolu3on of Biodiversity Pierre‐Henri Gouyon (MNHN) Ecole Théma3que Michael Ghil La Rochelle 2012 Biodiversity? Biodiversity www.mnhn.fr/oseb/GOUYON-Pierre-Henri Biodiversity: Linné's point of view “All species reckon the origin of their stock in the first instance from the veritable hand of the Almighty Creator: for the Author of Nature, when he created species, imposed on his creations an eternal law of reproduction and multiplication within the limits of their proper types. He did indeed in many instances allow them the power of sporting in their outward appearance, but never that of passing from one species to another. Hence today there are two kinds of difference between plants: one a true difference, the diversity produced by the all-wise hand of the Almighty, but the other, variation in the outside shell, the work of Nature in a sportive mood.” What is a species? The concept of species must evolve: instead of being founded on the idea of resemblance, it will be founded on the idea of descent. This has been the general trend of systematics since the XVIIIth century: Common descent is the criterion for taxa at all levels (clades). Diversity among species Biodiversity & Progress Biodiversity & Progress De la Nature. Première Vue. Histoire générale et particulière. Imprimerie royale. Paris. 1764. On Nature. First sight. General and specific history. Royal Printing works. Paris. 1764. Voyez ces plages désertes, ces tristes contrées où l’homme n’a jamais résidé; couvertes ou plutôt hérissées de bois épais et noirs dans toutes les parties élevées, des arbres sans écorce et sans cime, courbés, rompus, tombant de vétusté, d’autres, en plus grand nombre, gisant au pied des premiers, pour pourrir sur des monceaux déjà pourris, étouffent, ensevelissent les germes prêts à éclore. See these deserted beaches, these sad countries where man has never lived; covered or rather spiked with black and thick woods in every highland, trees with no bark nor top, bent, broken, falling into decay, others, in greater number, lying at the foot of the former, to rot over already rotting heaps, suffocate, bury the seeds ready to germinate. La nature qui, partout ailleurs, brille par sa jeunesse, parait ici dans la décrépitude; la terre, surchargée par le poids, surmontée par les débris de ses productions, n’offre, au lieu d’une verdure florissante, qu’un espace encombré, traversé de vieux arbres chargés de plantes parasites, de lichens, d’agarics, fruits impurs de la corruption: Nature which, everywhere else, is conspicuous by its youth, appears here in decrepitude, the earth, overloaded by the weight, surmounted by the debris of its productions, offers, instead of flourishing greenery, only a crowded space, ran through by old trees loaded with parasitic plants, with lichens, with agarics, impure fruits of corruption: dans toutes les parties basses, des eaux mortes et croupissantes, faute d’être conduites et dirigées; des terrains fangeux, qui n’étant ni solides ni liquides, sont inabordables, et demeurent également inutiles aux habitants de la terre et des eaux; des marécages qui, couverts de plantes aquatiques et fétides, ne nourrissent que des insectes vénéneux et servent de repaire aux animaux immondes. in all the lower parts, stagnant and dead water, for lack of guidance and management; muddy lands, which, being neither solid nor liquid, are inaccessible, and also remain useless to the inhabitants of earth and waters; swamps, covered with aquatic and fetid plants, that feed only poisonous insects and provide a den to squalid animals. Entre ces marais infects qui occupent les lieux bas, et les forêts décrépites qui couvrent les terres élevées, s’étendent des espèces de landes, des savanes, qui n’ont rien de commun avec nos prairies; les mauvaises herbes y surmontent, y étouffent les bonnes: ce n’est point ce gazon fin qui semble faire le duvet de la terre, ce n’est point cette pelouse émaillée qui annonce sa brillante fécondité; Stretching between the foul marshes that occupy the bottom places, and the decrepit forests that cover the high lands, there are kind of moorlands, savannas, which have nothing in common with our meadows, overcome by weeds choking the good plants: it is not this thin grass that seems to be the down of the earth, it is not this enamelled lawn announcing its brilliant fertility; ce sont des végétaux agrestes, des herbes dures, épineuses, entrelacées les unes dans les autres, qui semblent moins tenir à la terre qu’elles ne tiennent entre elles, et qui, se desséchant et repoussant successivement les unes sur les autres, forment une bourre grossière épaisse de plusieurs pieds. It is rustic plants, hard, thorny weeds, interlaced within each other, which seem to hold less to the ground than amongst themselves, and which, drying out and growing again over each other, form a several-feet-thick coarse stuffing. Nulle route, nulle communication, nul vestige d’intelligence dans ces lieux sauvages; l’homme, obligé de suivre les sentiers de la bête farouche, s’il veut les parcourir; contraint de veiller sans cesse pour éviter d’en devenir la proie; effrayé de leurs rugissements, saisi du silence même de ces profondes solitude, il rebrousse chemin et dit: La Nature brute est hideuse et mourante; c’est Moi, Moi seul qui peux la rendre agréable et vivante: No road, no communication, no vestige of intelligence in these wild areas; man, obliged to follow the paths of the wild beast, if he wants to cross them, forced to watch constantly to avoid becoming their prey ; frightened by their roaring, overcome with the very silence of this deep loneliness, he turns back and says: The wilderness is hideous and dying; I, and only I, can make it pleasant and alive: desséchons ces marais, animons ces eaux mortes en les faisant couler, formons-en des ruisseaux, des canaux; employons cet élément actif et dévorant qu’on nous avait caché et que nous ne devons qu’à nous-mêmes, mettons le feu à cette bourre superflue, à ces vieilles forêts déjà à demi consommées; achevons de détruire avec le fer ce que le feu n’aura pu consumer: … let’s dry these marshes, animate these stagnant waters by making them flow, let’s turn them into streams, canals, let’s use the active and devouring element which was hidden to us and that we only owe to ourselves, let’s set fire to the unnecessary stuffing, to these already half consumed old forests, let’s finish destroying by sword what couldn’t have been consumed by fire:... servons-nous de ces nouveaux aides pour achever notre ouvrage; que le bœuf soumis au joug emploie ses forces et le poids de sa masse à sillonner la terre, qu’elle rajeunisse par la culture: une nature nouvelle va sortir de nos mains Quelle est belle, cette Nature cultivée ! que par les soins de l’homme elle est brillante et pompeusement parée ! » Let’s use these new assistants in order to complete our work; let the ox, harnessed with a yoke use the power of his mass to plough the ground, let it rejuvenate through cultivation: a new nature will come out of our hands. How beautiful this cultivated nature is! How bright and pompously adorned she is, thanks to the care of Man,ʺ de Maillet Voltaire L’Homme aux quarante écus. (1768.) Voltaire Man of 40 crowns. (1768.) Voltaire VI. — Nouvelles douleurs occasionnées par les nouveaux systèmes. (Ce petit morceau est tiré des manuscrits d’un vieux solitaire.) VI. — New pains resulting from new systems. (This little piece is extracted from the manuscripts of an old loner.) Je vois que de si bons citoyens se sont amusés à gouverner les États, et à se mettre à la place des rois; si d’autres se sont crus des Triptolèmes et des Cérès, il y en a de plus fiers qui se sont mis sans façon à la place de Dieu, et qui ont créé l’univers avec leur plume, comme Dieu le créa autrefois par la parole. I see that if good citizens have played the game of governing the States; and taking the place of kings, if others have believed themselves to be Triptolemes and Ceres, there are some others, even prouder, who have taken the place of God, and who created the world with their pen, just like God created it in the past with the word 1748 : De l'esprit des lois de Montesquieu 1756 : Traité de la culture des terres de Duhamel du Monceau adapté de l’œuvre de Jethro Tull. Un des premiers qui se présenta à mes adorations fut un descendant de Thalès, nommé Telliamed*, qui m’apprit que les montagnes et les hommes sont produits par les eaux de la mer. Il y eut d’abord de beaux hommes marins qui ensuite devinrent amphibies. Leur belle queue fourchue se changea en cuisses et en jambes. J’étais encore tout plein des Métamorphoses d’Ovide, et d’un livre où il était démontré que la race des hommes était bâtarde d’une race de babouins: j’aimais autant descendre d’un poisson que d’un singe. One of the first people who came to my adorations was a descendant of Thales, named Telliamed, who told me that the mountains and men are produced by the waters of the sea. First there were handsome marine men who then became amphibious. Their beautiful forked tail transformed into thighs and legs. I was still remembering Ovid's Metamorphoses, and a book where it was shown that the human race was a bastard race of baboons: I’d rather descend from a fish than from a monkey. *Telliamed est le pseudonyme (son nom à l’envers) de « de Maillet » *Telliamed is the pseudonyme (his name reversed) of « de Maillet » Avec le temps j’eus quelques doutes sur cette généalogie, et même sur la formation des montagnes. «Quoi! me dit-il, vous ne savez pas que les courants de la mer, qui jettent toujours du sable à droite et à gauche à dix ou douze pieds de hauteur, tout au plus, ont produit, dans une suite infinie de siècles, des montagnes de vingt mille pieds de haut, lesquelles ne sont pas de sable? Apprenez que la mer a nécessairement couvert tout le globe. La preuve en est qu’on a vu des ancres de vaisseau sur le mont Saint-Bernard, qui étaient là plusieurs siècles avant que les hommes eussent des vaisseaux. « Figurez-vous que la terre est un globe de verre qui a été longtemps tout couvert d’eau. » With time I had some doubts about this genealogy, and even about the formation of mountains. "What! he said, you do not know that the currents of the sea, which always throw sand to the right and to the left ten or twelve feet high, at most, produced during an infinite series of centuries, twentythousand-feet-high mountains, which are not of sand? Know that the sea must have covered the entire globe. The proof is that we saw ship anchors on Mount St. Bernard, which had been here centuries before the men had vessels. "Imagine that the earth is a globe of glass which has long been all covered with water.” Plus il m’endoctrinait, plus je devenais incrédule: « Quoi donc! me dit-il, n’avez-vous pas vu le falun de Touraine à trente-six lieues de la mer? C’est un amas de coquilles avec lesquelles on engraisse la terre comme avec du fumier. Or, si la mer a déposé dans la succession des temps une mine entière de coquilles à trente-six lieues de l’Océan, pourquoi n’aura-t-elle pas été jusqu’à trois mille lieues pendant plusieurs siècles sur notre globe de verre?» The more he indoctrinated me, the more skeptical I was: “So what? he said, have not you seen the coquina of Touraine at thirty-six leagues from the sea? It's a heap of shells with which people fertilize the earth as with manure. Now, if the sea has deposited in the course of time a mine full of shells thirty-six leagues from the ocean, why will it not have been up to three thousand miles for centuries on our glass globe?" Je lui répondis: « Monsieur Telliamed, il y a des gens qui font quinze lieues par jour à pied; mais ils ne peuvent en faire cinquante. Je ne crois pas que mon jardin soit de verre; et quant à votre falun, je doute encore qu’il soit un lit de coquilles de mer. Il se pourrait bien que ce ne fût qu’une mine de petites pierres calcaires qui prennent aisément la forme des fragments de coquilles, comme il y a des pierres qui sont figurées en langues, et qui ne sont point des langues; en étoiles, et qui ne sont point des astres; en serpents roulés sur eux-mêmes, et qui ne sont point des serpents; en parties naturelles du beau sexe, et qui ne sont point pourtant les dépouilles des dames. On voit des dendrites, des pierres figurées, qui représentent des arbres et des maisons, sans que jamais ces petites pierres aient été des maisons et des chênes. I replied, "Sir Telliamed, there are people who walk for forty leagues a day, but they cannot make it fifty. I do not think my garden is made of glass, and about your coquina, I still doubt it is a bed of sea shells. It could be only a mine of small pieces of limestone that takes easily the shape of shell fragments as there are stones that look like tongues, and which are not tongues, as stars, and which are not stars, as snakes rolled-in on themselves, and which are not snakes; in natural parts of the fair sex, and yet are not remains of ladies. We see dendrites, sculptured stones which look like trees and houses, without ever being houses or oak trees. « Si la mer avait déposé tant de lits de coquilles en Touraine, pourquoi aurait-elle négligé la Bretagne, la Normandie, la Picardie, et toutes les autres côtes? J’ai bien peur que ce falun tant vanté ne vienne pas plus de la mer que les hommes. Et quand la mer se serait répandue à trente-six lieues, ce n’est pas à dire qu’elle ait été jusqu’à trois mille, et même jusqu’à trois cents, et que toutes les montagnes aient été produites par les eaux. J’aimerais autant dire que le Caucase a formé la mer, que de prétendre que la mer a fait le Caucase. "If the sea had put so many beds of shells in Touraine, why would she have neglected Brittany, Normandy, Picardy, and other coasts? I am afraid that this famous shell sand came neither from the sea nor from men. And when the sea would spread to thirty-six leagues, this is not to say that it was up to three thousand, and even three hundred, and all the mountains have been formed by the water. I would say that the Caucasus has formed the sea, as well as claim that the sea made the Caucasus. — Mais, monsieur l’incrédule, que répondrez-vous aux huîtres pétrifiées qu’on a trouvées sur le sommet des Alpes? — Je répondrai, monsieur le créateur, que je n’ai pas vu plus d’huîtres pétrifiées que d’ancres de vaisseau sur le haut du MontCenis. Je répondrai ce qu’on a déjà dit, qu’on a trouvé des écailles d’huîtres (qui se pétrifient aisément) à de très grandes distances de la mer, comme on a déterré des médailles romaines à cent lieues de Rome; et j’aime mieux croire que des pèlerins de Saint-Jacques ont laissé quelques coquilles vers Saint-Maurice, que d’imaginer que la mer a formé le mont Saint-Bernard. — But, Mr. Unbeliever, what would you answer about petrified oysters that have been found on the top of the Alps? — My answer, Mr. Creator, I have not seen more petrified oysters then vessel anchors at the top of the Mont-Cenis. I will answer what has been said before, that we found oyster shells (which are easily petrified) at great distances from the sea, as Roman medals have been exhumed hundred miles from Rome, and I’d rather believe that the pilgrims of SaintJacques left a few shells towards Saint-Maurice, than imagine that Mount St. Bernard has been formed by the sea. « Il y a des coquillages partout; mais est-il bien sûr qu’ils ne soient pas les dépouilles des testacés et des crustacés de nos lacs et de nos rivières, aussi bien que des petits poissons marins? — Monsieur l’incrédule, je vous tournerai en ridicule dans le monde que je me propose de créer. — Monsieur le créateur, à vous permis; chacun est le maître dans son monde; mais vous ne me ferez jamais croire que celui où nous sommes soit de verre, ni que quelques coquilles soient des démonstrations que la mer a produit les Alpes et le mont Taurus. "There are shells everywhere, but is it certain that they are not the remains of shellfish and crustaceans in our lakes and rivers, as well as small marine fish? — Mister Unbeliever, I will ridicule you in the world that I intend to create. — Mister Creator, as you wish, everybody is master in his own world, but you will never make me believe that the one we are in is made of glass or that some shells are demonstrations that the sea produced the Alps and Mount Taurus. Vous savez qu’il n’y a aucune coquille dans les montagnes d’Amérique. Il faut que ce ne soit pas vous qui ayez créé cet hémisphère, et que vous vous soyez contenté de former l’ancien monde: c’est bien assez. — Monsieur, monsieur, si on n’a pas découvert de coquilles sur les montagnes d’Amérique, on en découvrira. — Monsieur, c’est parler en créateur qui sait son secret, et qui est sûr de son fait. Je vous abandonne, si vous voulez, votre falun, pourvu que vous me laissiez mes montagnes. Je suis d’ailleurs le très humble et très obéissant serviteur de Votre Providence. » You know that there is no shell in the mountains of America. It must be that you have not created this hemisphere, and you were happy with forming the ancient world: it is far enough. — Sir, sir, if we did not find shells on the mountains of America, we will discover them — Sir, it's talking as a creator who knows his secret, and who is sure of his deeds. I let you, if you want, your shell sand, provided you let me my mountains. By the way, I am the most humble and obedient servant of Your Providence. " Lamarck Lamarck Lamarck long beleived that there existed « constant species » but he later writes (in 1802): « Maintenant, je suis convaincu que j'étois dans l'erreur à cet égard et qu'il n'y a dans la nature que des individus » « Je donne le nom d'espèce à toute collection d'individus qui, pendant une longue durée, se ressemblent tellement par toutes leurs parties comparées entr'elles, que ces individus ne présentent que de petites différences accidentelles » Lamarck Lamarck Darwin Natural selection • Reproduction • Variation • Choice Process repeated over numerous generations! It is interesting to contemplate a tangled bank, clothed with many plants of many kinds, with birds singing on the bushes, with various insects flitting about, and with worms crawling through the damp earth, and to reflect that these elaborately constructed forms, so different from each other, and dependent upon each other in so complex a manner, have all been produced by laws acting around us. These laws, taken in the largest sense, being Growth with reproduction; Inheritance which is almost implied by reproduction; Variability from the indirect and direct action of the conditions of life, and from use and disuse; a Ratio of Increase so high as to lead to a Struggle for Life, and as a consequence to Natural Selection, entailing Divergence of Character and the Extinction of less improved forms. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone circling on according to the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved. Thus, from the war of nature, from famine and death, the most exalted object which we are capable of conceiving, namely, the production of the higher animals, directly follows. There is grandeur in this view of life, with its several powers, having been originally breathed by the Creator into a few forms or into one; and that, whilst this planet has gone circling on according to. the fixed law of gravity, from so simple a beginning endless forms most beautiful and most wonderful have been, and are being evolved It is often said that all the conditions for the first production of a living organism are present, which could ever have been present. But if (and Oh! what a big if!) we could conceive in some warm little pond, with all sorts of ammonia and phosphoric salts, light, heat, electricity, etc., present, that a protein compound was chemically formed ready to undergo still more complex changes, at the present day such matter would be instantly devoured or absorbed, which would not have been the case before living creatures were formed. […] It is mere rubbish thinking at present of the origin of life; one might as well think of the origin of matter Certainly no clear line of demarcation has as yet been drawn between species and subspecies-that is, the forms which in the opinion of some naturalists come very near to, but do not quite arrive at the rank of species ; or, again, between sub-species and well-marked varieties, or between lesser varieties and individual differences. These differences blend into each other in an insensible series ; and a series impresses the mind with the idea of an actual passage. I am often in despair in making the generality of naturalists even comprehend me. Intelligent men who are not naturalists and have not a bigoted idea of the term species, show more clearness of mind. Weissman : one transmits only what one received What remains with time in the process of evolution? (What does selection act on?) Matter / Information • Physiology : fluxes of matter & energy • C + O2 → C02 • Genetics : fluxes of information • DNA → RNA • Parents → Offspring Individuals are contingent artefacts invented by genes in order to be reproduced Biodiversité, Science & Société N. S. : … l’être humain peut être dangereux. C’est d’ailleurs pour cette raison que nous avons tant besoin de la culture, de la civilisation. Il n’y a pas d’un côté des individus dangereux et de l’autre des innocents. Non, chaque homme est en lui-même porteur de beaucoup d’innocence et de dangers. N.S.: Human being can be dangerous. By the way, it is for this reason that we need culture and civilization. There are no dangerous people on one side and innocent on the other. No, every individual himself has much of innocence and dangerousness. M. O. : Je ne suis pas rousseauiste et ne soutiendrais pas que l’homme est naturellement bon. À mon sens, on ne naît ni bon ni mauvais. On le devient, car ce sont les circonstances qui fabriquent l’homme. M.O.: I'm not one of the tenants of Rousseau and I will not support the idea that man is naturally good. To my mind, we are born neither good nor bad. One becomes it, because a person is built by the circumstances. N. S. : Mais que faites-vous de nos choix, de la liberté de chacun ? M. O. : Je ne leur donnerais pas une importance exagérée. Il y a beaucoup de choses que nous ne choisissons pas. Vous n’avez pas choisi votre sexualité parmi plusieurs formules, par exemple. Un pédophile non plus. Il n’a pas décidé un beau matin, parmi toutes les orientations sexuelles possibles, d’être attiré par les enfants. Pour autant, on ne naît pas homosexuel, ni hétérosexuel, ni pédophile. Je pense que nous sommes façonnés, non pas par nos gènes, mais par notre environnement, par les conditions familiales et sociohistoriques dans lesquelles nous évoluons. N. S.: But what do you do with our choices, with freedom of each person? M.O.: I would not give them an exaggerated importance. There are many things that we do not choose. For instance, you did not choose your sexuality among several options. Neither does a pedophile. He has not decided one morning that, of all sexual possible orientations, to be attracted by children. However, we are not born homosexual or heterosexual, or pedophile. I think we are shaped not by our genes, but by our environment, family and socio-historical circumstances within which we live. N. S. : Je ne suis pas d’accord avec vous. J’inclinerais, pour ma part, à penser qu’on naît pédophile, et c’est d’ailleurs un problème que nous ne sachions soigner cette pathologie. Il y a 1 200 ou 1 300 jeunes qui se suicident en France chaque année, ce n’est pas parce que leurs parents s’en sont mal occupés ! Mais parce que, génétiquement, ils avaient une fragilité, une douleur préalable. Prenez les fumeurs : certains développent un cancer, d’autres non. Les premiers ont une faiblesse physiologique héréditaire. Les circonstances ne font pas tout, la part de l’inné est immense. N.S.: I do not agree with you. As for me, I am inclined to think that one is born paedophile, and this is a problem that we do not know how to treat this pathology. There are 1200 to 1300 young people who commit suicide in France every year; this is not because their parents raised them up badly! But because they had a genetic weakness, a prior pain. Take smokers: some develop cancer while others do not. The former have a hereditary physiological weakness. The circumstances are not everything; the innate part is tremendous. N. S. : Donc, ça vous intéresse, la complexité ? N.S.: So, the complexity, is it what you are interested in? M. O. : Bien sûr ! Il vaut mieux qu’on finisse sur un éloge de la complexité que sur le braquage idéologique de la première demiheure... M.O.: Of course! We’d better conclude on a eulogy of the complexity than on the ideological lock of the first half-hour… Biology is an empirical science (despite some theorization…) Progress & Biology .. . “Nature is neither moral nor immoral, Nature is non-moral.” T. H. Huxley In the Buck vs. Bell decision of May 2, 1927, the United States Supreme Court upheld a Virginia statute that provided for the eugenic sterilization for people considered genetically unfit. The Court’s decision, delivered by Oliver Wendell Holmes, Jr., included the infamous phrase "Three generations of imbeciles are enough.” Upholding Virginia’s sterilization statute provided the green light for similar laws in 30 states, under which an estimated 65,000 Americans were sterilized without their own consent or that of a family member. The mathematician, carried along on his flood of symbols, dealing apparently with purely formal truths, may still reach results of endless importance for our description of the physical universe. Modern science, as training the mind to an exact and impartial analysis of facts, is an education specially fitted to promote citizenship. The right to live does not connote the right of each man to reproduce his kind ... As we lessen the stringency of natural selection, and more and more of the weaklings and the unfit survive, we must increase the standard, mental and physical, of parentage. Darwinism, Medical Progress and Parentage (London 1912). Karl Pearson This new vision is both comprehensive and unitary. It integrates the fantastic diversity of the world into a single framework, the pattern of all-embracing evolutionary process. In this unitary vision, all kinds of splits and dualisms are healed. The entire cosmos is made out of one and the same world-stuff, operated by the same energy as we ourselves. "Mind" and "matter" appears as two aspects of our unitary mind-bodies. There is no separate supernatural realm: all phenomena are part of one natural process of evolution. There is no basic cleavage between science and religion; they are both organs of evolving humanity. This earth is one of the rare spots in the cosmos where mind has flowered. Man is a product of nearly three billion years of evolution, in whose person the evolutionary process has at last become conscious of itself and its possibilities. Whether he likes it or not, he is responsible for the whole further evolution of our planet The New Divinity by Julian Huxley Nikolay Ivanovich Vavilov Biodiversity in cultivated plants Their evolution from centers of origin in a context of isolation and exchanges "In the course of evolution nature has gone to endless trouble to see that every individual is unlike every other individual. We reproduce our kind by bringing the father's genes into contact with the mother's. These hereditary factors may be combined in an almost infinite number of ways. Physically and mentally, each one of us is unique. Any culture which, in the interests of efficiency or in the name of some political or religious dogma, seeks to standardize the human individual, commits an outrage against man's biological nature" Brave New World Revisited (1958) by Aldous Huxley GATTACA L’agent orange Cry 3A structure (front view) Cry 3A structure (top view) The structure is made up from three domains which are, from N to C terminus, a seven helix bundle, (Domain I) a triple antiparallel beta sheet domain (Domain II) and a beta-sheet sandwich (Domain III). Notice the 3 hypervariable loops in Domain II (arrowed). The core of the molecule is built from five sequence blocks which are a highly conserved feature of all the Bt toxins, indicating that all the proteins in this Cry family will adopt the same general fold. The discovery of the long, hydrophobic and amphipathic alpha helices of Domain I reinforced earlier computer-derived prediction that this region is equipped for transmembrane pore formation. When viewed from the top, domain I resembles a pore forming domain and is a candidate for the membrane insertion step. Studies suggest that the pore is initiated by insertion of a helical hairpin (alpha4/alpha5) from domain I with subsequent association of alpha4/alpha5 hairpins from several molecules to form an oligomeric helical bundle pore with a radius of 5-10 Angstroms. Le pollen et les graines se dispersent… Pollen and seeds are dispersed : • Invasive plants to come? • Weeds becoming resistant ? • How tro manage that? Pollen and seeds are dispersed. This has important consequences when genes are patented Monsanto Board of Directors Increases Quarterly Dividend to 17.5 Cents Per Share Dividend has increased nearly 200 percent since 2002 spinoff ST. LOUIS, Aug. 7 /PRNewswire-FirstCall/ -- Monsanto Company (NYSE: MON) today announced that its Board of Directors declared an increase in the quarterly dividend on its common shares from 12.5 cents per share to 17.5 cents per share, or an increase of 40 percent. The dividend is payable on Oct. 26, 2007, to shareowners of record on Oct. 5, 2007. Nature November 29, 2001 Vol. 414, pp. 541-543 T ransgenic DNA Introgressed Into Traditional Maize Landraces in Oaxaca, Mexico David Quist and Ignacio H. Chapela Department of Environmental Science, Policy and Management University of California Berkeley, California 94720-3110, USA (Correspondence and req u ests for materials should be addressed to I.H.C. e-mail: [email protected].) Svalbard : Noah's Ark? Svalbard : Noah's Ark? Svalbard : Noah's Ark or cemetery? Industrial farming does not always improve productivity per unit surface. Even when it does, it also -increases inequalities in terms of income -replaces farmers by corporations → It thus increases the number of poors and starvation Daedalus & Progress Dédale, l’ingénieur et la technique au service du Progrès… Pour se venger, Minos enferma Dédale et son fils Icare dans le Labyrinthe. Dédale fabriqua des ailes avec des plumes et de la cire pour s'échapper du Labyrinthe. Thank you www2.mnhn.fr/oseb/spip/GOUYON-Pierre-Henri Attribution-NonCommercial-ShareAlike 3.0 Unported You are free: to Share - to copy, distribute and transmit the work to Remix - to adapt the work Under the following conditions: Attribution. You must attribute the work in the manner specified by the author or licensor (but not in any way that suggests that they endorse you or your use of the work). Noncommercial. You may not use this work for commercial purposes. Share Alike. 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