About symmetry of flora and fauna

Why are we bilateral?

symmetry Spherical blue-green algae (cyanobacteria).

Photo: infofeed.org Why do most animals, and we – humans have bilateral (bilateral) symmetry? This is related to active movement in space .

Some unicellular organisms spend their entire lives going way up high in the water and their notions of “right-left” and “top-down” no significant difference – all sides are equal. So these creatures resemble field .

primitive multicellular attached to the bottom as anemones, apparently the terms “above” and “below” a difference, but the likelihood appear prey or predator left or right or front or rear is the same, but not above or below. They have radial symmetry or diedralna symmetry , which is a combination of radial and mirror..

simetriya simetriya starfish inhabit the bottom with radial symmetry

Photo: State University in Jamaica

symmetry Illustration: BaileyBio.com But when an animal begins to move inward, the terms “front” and “rear” are formed and acquire essential. The basic senses are moved to the front of the body, because it is more important to how we approach, rather than what we depart. But the left and right side of the living environment remain equally interesting – so fast-moving animals have bilateral symmetry, mirror symmetry .

It should be noted that symmetry affects only those systems that are directly related to physical activity – bone and muscle system, sensory organs, external form.

symmetry good example illustrating this idea are sea urchins. Slowly creeping types, all echinoderms are axisymmetric the fifth order (more precisely diedralna symmetry). Some sea urchins have changed their usual environment of life in the sand in which they actively dig and move. And under the rule statements, the spherical shell is flattened, slightly delayed – the body of sea urchin and becomes bilaterally symmetrical . It was found that the ancestors of echinoderms were actually bilateral, as evidenced by the bilateral symmetry of their larvae. This once again proves that the way of life, and especially the way of movement determines the symmetry of the body – a fast moving bilateral larvae later as adults still or slow gain radial symmetry.
sea urchins, acquired bilateral symmetry.

Photo: Kåre Telnes

fact echinoderms evolved from invertebrate with bilateral symmetry, as evidenced by some fossils and the study of their embryos. Their larvae also have bilateral symmetry.

First developed two broad beam forming bilateral symmetry, then another beam forming triradialna symmetry and then divide the total beam forming morphology of adults with five points. This is so model 2 +1 +2 . symmetry symmetry Illustration: Colin Sumrall

should be noted that symmetry affects only those systems that are directly related to physical activity – bone and muscle system, sensory organs, external form. Phylogenetic Evolution seeks to cause hereditary difference between right and left, but its effect stops the benefits derived from being mirror symmetrical layout of the component parts of his body. This may explain why our legs are more symmetrical than our internal organs. The position of our heart and twisting of the bowel we almost always left.

Again for chirality

modern natural science has reached an important discovery related to the symmetry concerning the differences between animate and inanimate. “Live” molecules, ie molecules of organic substances that make up living organisms other than “non-living”, ie produced artificially and mirror symmetry – as left and right glove. This property is called chirality – it talked about in ). Undead chiral molecules found in nature in both the “left” and the “dyasen” option, ie Chiral they are unclean. “Live” molecules can be oriented only – “left” or “right”, ie Chiral they are clean. For example, the spiral of a DNA molecule is always right, glucose is formed in the body with the right forms and fructose – left.

Therefore, the most important ability of living organisms is the creation of clean Chiral molecules – that is what determines the biochemical distinction between animate and inanimate.

Upside down

Throughout his life, we, and all living beings must oppose a constant downward force – gravity. Because of him, our mirror symmetry is a vertical axis, not horizontal. We tend to identify with the image in the mirror and hardly anyone would notice if the world around us is replaced by its mirror image. But if it is turned upside down? On our inability to perceive the image upwards are based images from paired images that look different as they turn 180 °, very popular at the time.

Following examples are rotated with mouse only CSS, I assure you, the pictures are not replaced. If your browser is old and can not be rotated by placing the mouse over them, then press here for the Mona Lisa and here for the next girl.

illusion Is this the real Mona Lisa?It seems roughly normal, but if you put your mouse over it, then you will uncover a terrible image. Why is it so difficult to recognize Mona Lisa changed when the picture is upside down? on sew mind is not able to better recognize rotated 180 ° objects. Illustration: hemmy.net illusionThis girl is smiling, but is it true…

Illustration: danielng.com

Paradoxically, precisely such a character affects our retina and the data is processed by an area of ​​the brain called the visual cortex, followed by the rest of the brain that trying to give meaning to what we see.Image that affects the retina has inversion symmetry . symmetry Illustration: danielng.com

In one experiment, which was held for the first time in 1896, a psychologist at the University of California at Berkeley, George Malcolm Stratton ( George Malcolm Stratton ) to put special glasses that made everything seem a head. Incredibly, after several days of disorientation, his brain started automatically corrects perceived images and they are seen in the right way again.

Symmetry of flowers

Most researchers of social psychology would agree that those who are considered the most attractive and most are symmetrical. Physical balance of right and left half is the primary hallmark of health and therefore beauty. What about plants?

 symmetry Despite the apparent complexity and the variety of colors, all the flowers actually have one of two possible types of symmetry – radial and bilateral ( zigomorf) symmetry. Plants do not move, firmly attached to the ground and each direction is equal to them both actinides, it is normal to develop radial symmetry diedralna (star), respectively.These include buttercups, lilies, tulips, roses, dahlias, daisies, and many other flowers. This pattern of symmetry was first released with flowers and is more primitive.
Photo: Dahlia Special

It is interesting why some plants and their flowers have bilateral symmetry of plants it is called zigomorfna . These include acacia, violets, and in general all papilionacea lipped and orchids naturally. What had this?

Recently, a team of ecologists and geneticists Spanish (Francisco Perfectti and Juan Pedro M. Camacho, José M. Gómez ), reported in The American Naturalist, those plants that have bilateral symmetry more attractive to insects from flowers with simple radial symmetry. The researchers found that plants with bilateral symmetrical flowers are visited by pollinators and had higher vitality, as measured by the number of seeds produced and survivors who have more than one plant with radially symmetrical flowers.
play pause images are from the movie “Microcosmos”
Photo: maltawildplants.com bumble bees (Bombus Terrestris), no experience with symmetrical and asymmetrical models and appears to have innate preference for bilateral symmetry.The earliest fossils of bilateral flowers are from the lower Tertiary (see ), and this evolution probably began in the Upper Cretaceous.

Development of bilateral flower is associated with the presence of social insects in the Upper Cretaceous and

A radially symmetric saga begun by Carl Linnaeus

Bilateral symmetry allows the development of flowers that are specifically adapted to insect pollinators, through the study of these mutations, scientists are able to understand more about the evolution of plants and insects with koevolyutsiyata..

 Linaria vulgaris f. peloria first indication that color symmetry is under genetic control comes from Carl Linnaeus, the father of plant and animal classification. He noticed near Stockholm strange plant – all signs of pennywort ( Linaria vulgaris ) Zhivovlekovi from family (Plantaginaceae), but instead of the usual bilateral symmetry, the color was a radially symmetric form . Linnaeus called him “ peloria “, the Greek word for Monster , not because it’s ugly, but because it has implications for the monstrous belief in immutability of species.

“This is certainly no less remarkable than if a cow give birth to a calf with the head of a wolf,” he wrote.

His system of plant classification is based on the structure of color and therefore decided that this unusual flower belongs to a completely new look. As in all other respects like ordinary pennywort, Linnaeus concluded that these peculiar plants arise from the “transformation” of a common type pennywort in a new form – a radical idea at a time when species were considered permanent, eternal acts of the Creator.

After 250 years of Enrico Coen Research Centre in Norwich has discovered a gene responsible for the mutation, according to research published in the journal “Nature.” For the “monstrous” forms are caused by natural mutation of a single gene called cycloidea , which requires bilateral symmetry in flower buds even when they are very young. In Peloria this gene is inactive, resulting in a radially symmetrical flowers.

So far peloric flovers found among the many species of orchids and other plants including such Linaria and Antirrhinum as a garden flower puppy.

 Linaria vulgaris Photos: John Grimshaw’s Garden Diary


Bэkmologiya , becmology.ru
Zhivыe sistemы.
Pochemu mы not germafroditы or what-chto polyze asimmetrii o , S.Afonykin
Echinoderm Symmetry , Colin Sumrall
Origins of radial symmetry identified in an echinoderm during adult development and the inferred axes of ancestral bilateral symmetry, Valerie B Morris
In Lust with Symmetry , Julie Ardery
The Invisible Colours of Flowers
Symmetry is in the eye of the beeholder: innate preference for bilateral symmetry in flower- naïve bumblebees. Rodríguez I, Gumbert A, Hempel de Ibarra N, Kunze J, Giurfa M.
How Did Bilaterally Symmetric Flowers Evolve From Radially Symmetric Ones? , The American Naturalist 167:10
Variation and Evolution in Plants and Microorganisms: Toward a New Synthesis 50 Years after Stebbins ( 2000) National Academy of Sciences (NAS)
Peloria , John Grimshaw’s Garden Diary

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5 Responses to “About symmetry of flora and fauna”

  1. ivo_isa says:

    “…На неспособността ни да възприемем образ, обърнат нагоре се основат картинки, много популярни на времето…”
    Ако беше вярно нямаше да разпознаваме предметите стоящи в различно положение. А и както сама посочихте образът върху ретината е инверсна симетрия – горе -> долу ; ляво -> дясно.
    Мисля, че е по-скоро следствие от начина на разпознаване. Мозъкът търси в паметта подобен образ. На това се основават зрителните илюзии.

    • Vanya says:

      Точно така, става въпрос за зрителните илюзии. Може би наистина трябва да сложа една картинка за илюстрация. Да, образът върху ретината е инверсен, но мозъкът ни обръща отново образа. Тук исках да подчертая, че обърнатият ляво-дясно образ не дразни,а обърнатия горе-долу образ не се възприема лесно, трудно го забелязваме. Всъщност ние виждаме по-скоро с мозъка, а не с очите, нали?

  2. ivo_isa says:

    Да. Очите гледат, а вижда мозъкът. :smile:

  3. ivo_isa says:

    Но в случая с тези двойни картинки правото изображение заглушава обърнатото. Ако беше само обърнатото нямаше да е трудно за разпознаване. Особено, ако предварително е виждано в право положение.

  4. When someone writes an piece of writing he/she keeps the thought
    of a user in his/her brain that how a user can know
    it. Therefore that’s why this piece of writing is outstdanding.

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