How did Evolution produce Symmetry?

One example, but how many others are there? Like I said, evolution may say that natural selection decides on which animals live and die, but, like in the example with the magnet, wouldn't there be more non-symmetrical results?

Asymmetry would be the product of necessity outweighing practical economy.

meaning that the animals that aren't symmetrical would die, also meaning that the dead animals would leave behind skeletons, most of which would become fossils,

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meaning that the animals that aren't symmetrical would die, also meaning that the dead animals would leave behind skeletons, most of which would become fossils,

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Wrong. Very, very few animals leave behind fossils. Fossilization requires rapid burial, something that does not occur to most species. You have to get the organism down to where there's almost no oxygen before it fully decomposes.We're talking an individual verses an entire worldwide population. The worldwide population is vastly more likely to have a member fossilize.------------------
"Illuminant light,
illuminate me."

well, the creature that is non-symmetrical, (the individual) WOULD be part of a worldwide population if they hadn't died bc of "natural selection,"as i said w/ the magnets, there would be more non-symmetrical creatures that evolved than symmetrical, making the non-symmetrical more common,I'm sure that just as many of the non-symmetrical would have been buried quickly, probably even more, since they wouldn't be able to move as quickly.

An asymmetrical adaptation for the purposes of assuming a niche and thereby taking advantage of an opportunity for survival does not necessarily mean "that the (asymmetrical) animals ... would die ..."Rather I am saying that if the asymmetrical animal (or plant) successfully assumes certain non-symmetrical features for purposes of protection/survival, that those species would continue to specialize with those features and in that niche.I supplied two examples: The flatfish (an animal) and the Sassafrass tree (a plant) that have successfully developed asymmetrical features.Rei answered the "most of which would become fossils" misconception.

Re: Asymmetrical individuals not being able to move very fast or adeptly.Okay, COD, you may be onto something here. Maybe, just maybe, an asymmetrical individual would not have the motor coordination of a symmetrical individual, and when trying to escape an onrushing primordal mudflow from the Deluge would spin, sputter, flop, and flounder out of control and fall over the edge of the flat earth and once outside the razor thin field of gravity would caroom into outer space![This message has been edited by Abshalom, 12-15-2003][This message has been edited by Abshalom, 12-15-2003]

so... wut ur sayin is
1. that bc an animal has an extra leg or arm or somethin on one side, it won't become a fossil?and2. if that is the way it works, then how do you explain cancer? A mutation in the cells, wouldn't cancer be non-existant? After all, it doesn't increase the chance of survival or protect the creature in any way, so why do cancer cells still form?Anyway, I g2g for now, I have a test tomorrow and more algebra homework... sigh... I'll respond 2 ne comments in the future

COD:Your homework and subsequent success in education is far more important than your participation in this or any other discussion forum. Do not this discussion interfere with doing well in school. Peace.

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well, the creature that is non-symmetrical, (the individual) WOULD be part of a worldwide population if they hadn't died bc of "natural selection,"

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No, there would be one of them, and it would die. One, compared to a population of millions, billions, or even trillions, is virtually insignificant. Also, the nature of HOX genes (genes that determine where things go on the body) make asymmetrical features less likely (although still possible).Also, another thing that has not been brought up is issues of rate of change. I think you have a mental image of, say, a wolf having a pup that has giant legs on one side of its body, and stubby ones on the other. It doesn't work that way. Even punctuated equilibrium changes, at the base level, still work through gradualistic change. Mutations - by and large - cause very small changes individually. Only the accumulation of tiny changes, as a general rule, produces significant differences. There are many processes which actually facilitate the aforementioned accumulation, such as the ability of genes to copy themselves across DNA and the nature of protein expression.

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I'm sure that just as many of the non-symmetrical would have been buried quickly, probably even more, since they wouldn't be able to move as quickly.

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For most animals, "getting buried quickly" has nothing to do with the animal itself. It takes a mudslide, a cave-in, or other such phenomina. If you can't move well, your most likely outcome is not to be buried alive, but to be eaten by a predator - it increases your odds of death by most methods equally.------------------
"Illuminant light,
illuminate me."

Cancer is, in my opinion, a self-regulatory process of life. When cells begin to function erroneously, this can be an indication of a lack of fitness. Outside influences can be at play, but so can heredity. Life chooses to preserve resources altruistically, and one way is by "cellular suicide". Granted, cancer can and should be dealt with if possible. Many people live wonderful lives after successful battles with cancer. But some that do, produce offspring with the same potential obstacles. Sometimes, cancer either isn't found in time, or is simply overpowering to the body. The result is that less fit individuals are disadvantaged reproductively - through heredity and early death. Exactly how this plays into symmetry I cannot say, but I do openly suggest that the functionality cancer exhibits might be due to some of those genes human beings don't understand yet.PS- ChildOfGod, I am sorry on behalf of the human being who keeps ridiculing your name. I guess that is part of the definition of "debunk" though. How one can think others take their opinions seriously with attitudes like that, I don't know.[This message has been edited by Human Being, 12-15-2003]

Animals were radially symmetrical before bilaterality occurred:The development of radial and biradial symmetry: The evolution of bilaterality
Martindale MQ, Henry JQ
AMERICAN ZOOLOGIST
38 (4): 672-684 SEP 1998Abstract:
Understanding the evolutionary origin of novel metazoan body plans continues to be one of the most sought after answers in biology. Perhaps the most profound change that may have occurred in the Metazoa is the appearance of bilaterally symmetrical forms from a presumably radially symmetrical ancestor. The symmetry properties of bilaterally symmetrical larval and adult metazoans are generally set up during the cleavage period while most "radially" symmetrical cnidarians do not display a stereotyped cleavage program. Ctenophores display biradial symmetry and may represent one intermediate form in the transition to bilateral symmetry, The early development of cnidarians and ctenophores is compared with respect to the timing and mechanisms of axial determination. The origin of the dorsal-ventral axis, and indeed the relationships of the major longitudinal axes, in cnidarians, ctenophores, and bilaterian animals are far from certain. The realization that many of the molecular mechanisms of axial determination are conserved throughout the Bilateria allows one to formulate a set of predictions as to their possible role in the origins of bilaterian ancestors.Some starfish are symmetrical, some are not!Developmental regulatory genes and echinoderm evolution
Wray GA, Lowe CJ
SYSTEMATIC BIOLOGY
49 (1): 28-51 MAR 2000Abstract
Modified interactions among developmental regulatory genes and changes in their expression domains are likely to be an important part of the developmental basis for evolutionary changes in morphology. Although developmental regulatory genes are now being studied in an increasing number of taxa, there has been little attempt to analyze the resulting data within an explicit phylogenetic context. Here we present comparative analyses of expression data from regulatory genes in the phylum Echinodermata, considering the implications for understanding both echinoderm evolution as well as the evolution of regulatory genes in general. Reconstructing the independent evolutionary histories of regulatory genes, their expression domains, their developmental roles, and the structures in which they are expressed reveals a number of distinct evolutionary patterns. A few of these patterns correspond to interpretations common in the literature, whereas others have received little prior mention. Together, the analyses indicate that the evolution of echinoderms involved: (1) the appearance of many apomorphic developmental roles and expression domains, some of which have plesiomorphic bilateral symmetry and others of which have apomorphic radial symmetry or left-right asymmetry; (2) the loss of some developmental roles and expression domains thought to be plesiomorphic for Bilateria; and (3) the retention of some developmental roles thought to be plesiomorphic for Bilateria, although with modification in expression domains. Some of the modifications within the Echinodermata concern adult structures; others, transient larval structures. Some changes apparently appeared early in echinoderm evolution (>450 Ma), whereas others probably happened more recently (

My guess this is THE SAME reasoning WITHIN AGGASSIZ's MIND to Produce a study on Jelly Fish OR Turtles AFTER his FOSSIL FISH PRINTING BUSINESS failed. There is a function in the complex plane that can visually responds to desires subjectively to find non radial symmetry in star fish and other related echinoderms. I have suggested on WoLFRAM SCIENCE that even Wolfram nodes might be tried but time is not yet to show how the professional response to my writing can be wrong when the "radial" notion of Matchette's "metaphysical" map is involuted in. Certainly Faradic INDUCTION could imply the physics and wolfram's new kind of science Could test whether or not "electrical fluid thus generated was the same as galvanic fluid."p85(The Ambiguous Frog The Galvani-Volta Controversy on Animal Electricity by J. Mandelbaum1992Princeton) This however remands some issues in valance/affinity chemistry no matter how the water is assorted across generations which being but an historical approach may have been missed by the professionals who have commented on my own"" ideas.If one is thinking of "physics" only in the sense of some post-Enstein generation (Feynamn, Figenbaum etc) then the word "fluid" IS a problem no matter the electrotonics as it would be impossible to lexically differentiate "aetheral fluid"p57 even if the grammer does not remand the same legologo for Wolfram.[This message has been edited by Brad McFall, 12-22-2003]