The Evolution Conflict

Discussion in 'Belief and Spirituality' started by Mohsin, Mar 18, 2004.

  1. louis

    louis New Member

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    evolution

    Hi, I'm new here...
    I don't have a university education and I'm probably not
    as smart as most of the people here. Maybe that's why I
    don't see a "conflict" between religion and evolution.
    As I understand it, religion proposes that a non-material
    "force" acted upon some inanimate material and changed
    it to animate-LIVING material... which eventualy became
    us humans. That sounds like quite a change. Some say
    it happened instantly - others say it happened gradualy,
    involving many trials and errors.
    I have never heard any scientists speculate about what
    CAUSED that change - they're interested only in making
    a catalogue of the trials and errors.
    What does that have to do with religion ?

    Louis...
     
  2. iBrian

    iBrian Peace, Love and Unity Staff Member

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    Quite right, Louis - what does it have to do with religion? The process of how life began is entirely conjectural in the worlds of science. How it might have developed after - ah, now that's the basis of evolutionary theory. :)

    But, hey, I'm just a dumbass who dropped out of a chemistry degree to seek life as a writer. :)
     
  3. juantoo3

    juantoo3 ʎʇıɹoɥʇnɐ uoıʇsǝnb

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    Brian, FWIW, I don't think anybody here considers you a dumbass. But, I must say, a chemistry degree? :)
     
  4. gluadys

    gluadys New Member

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    Hi. New here. Just found this forum today---well actually yesteday now that it is past midnight.

    I've been reading this thread and noticed many common errors about the theory of evolution. Just to note the ones on the final page:

    Substitution of part for the whole

    "For what is evolution but simple mutation" Quahom 1

    No, evolution is not simple mutation. It involves mutation + variation + natural selection + speciation.

    Failure to keep up to date on scientific discovery

    "The elusive missing link...is still missing. " Quahom 1

    many transitional forms have been found. A few of the best-known are archeopteryx (dinosaur to bird), ambulocetus natans (land mammal to whale) australopithecines (many species: ape to human) Of course, many have yet to be found, but which did you have in mind?

    Confusion about the different meanings of "may" and "must"

    "Similarity ('homology') is not an absolute indication of common ancestry (Evolution) but certainly points to a common designer (creation)." Quahom 1


    [aside: homology is only one kind of similarity. It is true that similarity is not necessarily an indication of common ancestry. But the particular similarities called homologies are.]

    Common design is merely permissive. Therefore it is non-predictive, non-explanatory and scientifically useless.
    Common ancestry necessitates homology, predicts it and explains it, including those homologies which are less-than-optimum design. This is what makes it a useful scientific tool for further research.

    Confusion of personal incredulity with scientific evidence

    "What if human and chimp DNA was even 96% homologous? What would that mean? Would it mean that humans could have 'evolved' from a common ancestor with chimps? Not at all! The amount of information in the 3 billion base pairs in the DNA in every human cell has been estimated to be equivalent to that in 1,000 books of encyclopaedia size. If humans were 'only' 4% different this still amounts to 120 million base pairs, equivalent to approximately 12 million words, or 40 large books of information. This is surely an impossible barrier for mutations (random changes) to cross." Quahom1

    Just because it is hard to believe doesn't mean it didn't happen.

    outdated notion of evolution as a progression to perfection

    "I have yet to see evidence of progression from one "species" into another."

    "I have also long thought it curious why terrapins (turtles/tortoises), crocodilians, and cockroaches haven't changed significantly in "millions" of years, as though evolution simply passed them right on by? Perhaps because they have reached the pinnacle of evolutionary perfection?" juantoo3

    In fact there are many observed instances of speciation, both in laboratory experiments and in nature. A particularly vivid one in the news a few months ago was the Nylon bug. A single nucleotide insertion with frameshift created a new bacterium with the never-before-seen capacity to digest nylon---an artificial fibre created in the late 1930s.

    No species, including our own has reached a pinnacle of evolutionary perfection, because there is no such thing. Evolution is change in response to environmental conditions. When environmental conditions change little, or when a species is able to function in a number of different environments, there is no pressure to change. Mutations still occur, offering novel possibilities, but they are not fixed into the species by natural selection.

    So it is a little surprising to find juantoo3 also saying:
    "But this in no way implies linear evolution from one species into another."

    You bet! Evolution is in no way linear, and once that is grasped, questions about missing links, crocodiles that haven't changed and fruit flies that are still fruit flies are seen for the red herrings they are. Evolution produces a branched network of relationships in which no species is more evolved than another, and in which there is no jumping from branch to branch.

    So much for the science. Now for theology

    Quahom1 said:

    " You say there is evolution, and I say yes and "Someone Started it". "

    I'll go further. Someone not only started it, but stayed with it and sustained the process and included humans in it.

    "... that he/she [chimp] will be in a different place than we will, ..."

    Why would s/he be? I don't know your faith, but as a Christian, it is my belief that God's intention is to redeem the whole of creation from the effects of sin and restore it to its original perfection. Animals and plants are part of that. The prophets of the Old Testament/Tanakh presented images of the kingdom of God which included animal and plant life. So why do you say the chimp will be in a different place than we will?
     
  5. juantoo3

    juantoo3 ʎʇıɹoɥʇnɐ uoıʇsǝnb

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    Kindest Regards, gluadys, and welcome to CR!
    I accept that evolution encompasses more than simple mutation, but would you be kind enough to differentiate between mutation and variation. Is not a mutation a variation? Further, aren't most mutations hindrances, what when applied to humans we often call "birth defects?" Natural selection is arbitrary, the "strong survive" is probably more accurately the "promiscuous survive", and birth defects are most generally a hindrance to promiscuity. While a different color coat may not be a hindrance to mating (the moths that shifted color from light to dark in industrial England, adaptation), an extra leg growing out of your back (Ripley's museum, St. Augustine, FL, birth defect) is a definite sexual turn-off.

    Agreed, many forms of life that no longer exist are contained in the fossil record. As I recall from a recent article (I believe it was by Gould), something on the order of 90% of the creatures that have existed on this planet are no longer here.

    Weren't the only two examples of Archeoperyx recently dismissed as (very clever) forgeries?

    I believe I see your point, and it is valid.

    Ah, but isn't Ockham's razor the traditional scientific standard? That is, if it sounds too good to be true, odds are exeedingly great that it is too good to be true?

    Was this natural, or synthetic, adaptation? I am aware of man-made bacterium created in the lab specifically to digest plastics as much as 15 years ago. Further, can this bacterium reproduce with "related" bacterium, specifically those from which it was derived? Not to mention, using single-celled creatures to denote how more complex creatures "speciate" is stretching the point. Even as simple as fruit flies, I still have not seen evidence that the new species is anything but fruit fly, or that the new species cannot mate with other fruit flies. This coordinates with what I was trying to express with hybridization and deliberate manipulation by selective breeding. And while fruit flies are used I presume because of the high turnover, at least among plants and domestic animals there is a distinct benefit to society. "Natural" selection, as it were.

    I just thought of a good example, Broccoli. Broccoli was developed by the Italian family that bears the name. (Aside, the James Bond films were produced by decendents of the Broccoli family and fortune.) Broccoli was derived from the Cole family, which includes cabbages. The difference being, while cabbage is generally grown for its leaves and/or heads, broccoli is grown for its flowers. Broccoli is a distinct species, no other Cole crop is anything like it. Yet all Cole crops (pick a member, any member) freely cross-pollinate with broccoli. Such seed is not considered by the backyard gardener to be worth saving.

    Another example, nectarines. They are a cross between plums and peaches (both of the rosacea family). Yet, like a mule, they are sterile.

    Now, with the current technology to splice genes and introduce components that are not inherent to a given species, is cheating. That could adequately be described as "un-natural" selection. For example, Alba the rabbit glows in black light. Alba is an albino rabbit, but she was genetically engineered by inserting a certain gene from a luminescent jelly fish into the embryo she was grown from. She is a truly beautiful creature, but to imply she is a new species, after deliberate tinkering by directly inserting what would not have come directly from her "normal" environment, is manipulation, not evolution, and not even adaptation. I understand a monkey has been created using the same technique.

    I don't see evolution as change in response to environmental conditions, adaptation is. Further, as cold-blooded reptiles, how did crocodilians and terrapins survive the natural disaster and pervasive ice-age(s) that killed off the other, "stronger" reptilians? Size? Smaller dinosaurs than crocs died. Environment? Other amphibious and water dwelling dinosaurs died. Crocs not only survived, they haven't changed. At least sharks changed (thank goodness!).

    Yet, along any given branch, the progress is linear. You are correct, jumping from limb to limb is not possible. The "progression" of man from an "apelike" ancestor however, is linear. I have heard much of speciation from time to time, and with all due respect to Vaj whom I hold in very high esteem, the "proof of the pudding" of no longer being able to breed within that family of creatures has not ever been demonstrated. At least no example that I am aware of. It has been conjectured, but it has not been demonstrated.

    Very good. This is in accord with my understanding.
     
  6. iBrian

    iBrian Peace, Love and Unity Staff Member

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    Hi gluadys, and welcome to CR. :)
     
  7. gluadys

    gluadys New Member

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    Thanks, juantoo. And thank you for a very comprehensive and thoughtful reply. I'll do the best I can with your questions.


    This is a very important distinction that is often overlooked. By "variation" I mean, as Darwin did, a variation in the actual morphology, physiology, and/or behaviour, etc, of an organism, such as a difference in colour, a difference in skeletal structure, a difference in dietary preference or whatever.

    Prior to the discovery of genetics and DNA, such variants, especially if they were startling and unusual, were called mutations. But today the term "mutation" is used mostly for a change in the DNA structure (genes or chromosomes) of the organism.

    Variation of the first sort is produced by genetic mutations. But not all genetic mutations produce variation. Many mutations occur in non-coding segments of the DNA and have no effect at all on the organism (though these are very useful for tracing genetic relationships). Others occur as new recessive genes and do not affect any organism which has only one copy of the mutated gene. It will show up as a variation only when it has spread far enough into the population that two organisms, both containing the recessive gene, mate and provide at least one of their offspring with two copies of the gene. Mendel noted that the phenomenon of recessive genes meant that two organisms of identical outward appearance could have differing genetic composition. He distinguished the genetic structure "genotype" from the outward appearance "phenotype".

    Now, what is most important to understand is that natural selection is not able to operate directly on genetic material. It operates only on actually existing organic variation--which relates to only a fraction of the genetic variation.

    Hence the need to distinguish mutation (genetic) from variation (organic).

    Not at all. Again, many mutations affect non-coding parts of the genome and have no effect one way or the other. Many other mutations are trivial in terms of fitness and also have no effect one way or another. (Such as the mutations which gave rise to variations in eye-colour in humans.) Some mutations are indeed harmful--but the range of harm can cover the gamut from mildly annoying to lethal. Some, for example, may do no actual harm to an individual but may make him/her less attractive as a mate. Studies have shown, for example, that other things being equal, a person has a better chance of being hired for a job if they are above average height. And since success as a provider tends to lead to sexual success as well, ... see what I mean? Birth defects are sometimes a result of a mutation, but they can be the result of other causes as well.

    An item to note. Any characteristic of any species which can occur in more than one form indicates an inherited mutation. That applies to eye-colour, hair texture, the shape of your nose, your blood-type, and many more varying characteristics.

    No, promiscuity doesn't help to ensure the survival of one's offspring. For one thing, we each provide our offspring with only half of their genetic make-up. The other half comes from their other parent. So even if we give them all great genes, we can't guarantee the other parent will.

    And worse, we can't even guarantee that we will give them great genes. For we have two copies of each gene, but we give only one copy to each of our offspring. And we have no control over which copy goes to which offspring. If you are of African origin, you have a higher chance than other humans of carrying a gene which can confer sickle-cell anemia. As long as you carry only one copy of this gene, it has no negative effect on you. But you will pass it on to about 50% of your offspring. Should one of them also inherit the same gene from the other parent, they will be distinctly less fit than their siblings.

    In short the random sorting of alleles in sexually-reproducing species negates most of the advantage that promiscuity might give to preserving the genes of a particular person.

    That's not to say it never has a role, but it becomes important only in specific cases such as a genetic bottleneck with founder effect.


    Actually, I have heard it is closer to 99%.

    I believe there are actually four. The question of forgery was raised and investigated. The investigation showed the allegation of forgery was not upheld by the evidence. Having been burned by a very famous scandal some years ago, the British Museum took no chances on another.


    It is a traditional standard, but it is not what you have described. Occam's thesis was that "entities ought not to be multiplied without necessity". Rendered in more modern terms, this means roughly that a simple explanation using fewer causes is to be preferred over a more complicated explanation demanding more causes----provided of course, that the simpler explanation does cover all the bases.

    It has nothing to do with the probability of an event. And, of course, the probability of an event which has occurred is 1, no matter how improbable the event may be in theory.

    It was a natural occurrence. The new bacterium was found by accident in the waste pool of a Japanese factory. Genetic comparison identified it as a flavobacterium and the single mutation which provided it with the capacity to use a new food source. And yes, even before finding this bacterium, others had been synthetically produced to digest plastics and oil. So this type of speciation has occurred both through human manipulation and naturally.

    Since bacteria reproduce asexually, it does not reproduce with related bacteria. It would be interesting to know if it ever exchanges genetic material with related bacteria (a process known as conjugation) and with what success, but I have no information on that.


    I got a message that this post is too long, so I am breaking it in two here. See my next post for a continuation of the discussion.
     
  8. gluadys

    gluadys New Member

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    The question is, given the processes used by evolution, why would you expect any other result? This goes back to understanding the branching nature of evolution. Once that is firmly in mind, this becomes a red herring question.


    Whether they cannot, I am not sure, but the results of some experiments have produced, from a single starting population, a variety of populations that will not mate with their sibling species. In terms of evolutionary mechanisms the refusal to mate is equally effective as an isolating mechanism as the inability to mate. Populations which do not inter-breed are effectively separate species.

    If you go to www.talkorigins.org and type "speciation" into their search engine, you can bring up a document called "Observed Instances of Speciation" which gives more detail on fruit fly speciation and speciation in other organisms. Part of the document called "29+ Evidences for Macro-evolution also gives details of field and labratory instances of speciation."

    Actually, as Darwin correctly observed in the first chapter of Origin of Species, if you want to get a new species, hybridization is not the best way to go about it. Mendel's work confirmed this. The first generation may be quite uniform and have all the good qualities you want to combine. But when you mate the individuals in the first generation to produce the next, genetic sorting re-aligns the characteristics so that you get a variety of results. And eventually, without careful control of the stock, it tends to revert to its wild form.

    The more effective way to get new species is through allopatric speciation. Start with one species. Divide it into groups. Put each group into a different environment. Let it remain there for several generations until it is adapted to that environment. Chances are that when you compare them with each other and with the original, you will find you now have several different species, each with its own distinct characteristics.

    It is true that hybridization sometimes gives a new species, but it is a rarer occurrence.

    Actually, the fact that they freely cross-pollinate means they are NOT separate species, but varieties of the same species, just as terriers and poodles are varieties of one canine species: the domestic dog.

    As the taxonomy below shows, cabbage, broccoli, kale, kohlrabi and brussel sprouts are all varieties of Brassica oleracea a species of mustard. Each has been bred by human gardeners for its particular characteristics.


    Brassica oleracea
    Brassica oleracea var. acephala (kale)
    Brassica oleracea var. alboglabra (Chinese kale)
    Brassica oleracea var. botrytis (cauliflower)
    Brassica oleracea var. capitata (cabbage)
    Brassica oleracea var. gemmifera (brussel sprouts)
    Brassica oleracea var. gongylodes (kohlrabi)
    Brassica oleracea var. italica (asparagus broccoli)
    Brassica oleracea var. medullosa (marrow-stem kale)
    Brassica oleracea var. oleracea
    Brassica oleracea var. ramosa (perennial kale)


    http://www.ncbi.nlm.nih.gov/Taxonom...&id=3700&lvl=3&lin=f&keep=1&srchmode=1&unlock

    Yes, good example both of the possibility of hybridization between closely related species, and of the limitations.

    Of course, biotechnology could not even be conceived without the fact of common descent. And you are right in saying that one new gene does not necessarily make a new species. That can happen, but rarely. For sexually reproducing species, the definition of species is related to the ability to mate and reproduce. If Alba can mate and reproduce with other rabbits of her species, then Alba is not a new species.

    Again this is a confusion of a part with the whole. Adaptation is a consequence of natural selection. Adaptation does not generally occur all at once in a single generation. It takes place through the accumulation of successive variations by natural selection. A species which has become fully adapted to its environment may have become a different species than the one that first migrated into the same environment.

    Adaptation, in and of itself requires a change in the distribution of gene alleles in the population. And that is the classic definition of evolution used today "A change in the distribution of alleles in a population that transcends generations." When such changes also lead to speciation, that is unquestionably evolution.

    One would have to be far more knowledgeable than I am about the environment in which crocodiles lived and of their behaviour patterns in response to cooler weather. The worst ice age, which killed off 98% of all species at the time, occurred long before crocodiles (or any vertebrates) came into existence. Also the great Permian-Triassic extinction occurred, I believe, before crocodiles existed, though I could be wrong on that one. I don't know off-hand the presumed date for the appearance of terrapins.

    So we are looking primarily at the Pleistocene ice ages. These were never as severe and never produced as much extinction as the earlier ones. If crocodiles lived primarily in the tropics, they would have survived ok. And even in temperate areas the ice ages were interspersed with warmer inter-glacial periods. So the extinction patterns of the Pleistocene were quite varied.

    No, even a branch is not linear, as it can divide into smaller branches which further divide into still smaller branches, and then divide again. The transition (not progression) from ape to human (a species, btw, that has two genders and is very incorrectly referred to by the name of just one of them) is not linear, as any examination of the hominid fossil record will show. Do a google search on hominids or homonid fossils and see what turns up.


    Are you still speaking of hominids or humans? You may be right. We cannot test, of course, for the possibility of a mating with viable offspring between a Homo sapiens and a Homo erectus, as we have no extant Homo erectus to participate. And it has been suggested that a mating of a human and a bonobo (the chimp species closest to human) might be possible. I very much doubt, however, that that supposition will be put to the test. Not ethical.
     
  9. gluadys

    gluadys New Member

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    Thanks, Brian. Have enjoyed your posts.
     
  10. juantoo3

    juantoo3 ʎʇıɹoɥʇnɐ uoıʇsǝnb

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    Kindest Regards, gluadys!

    You have given me some very interesting things to consider, thank you.

    BTW,
    You are right, political correctness is not my strong suit. My apologies if any offense was incurred. I was taught "old school,", and I tend to thoughtlessly use those old traditional terms when my concentration is elsewhere.
     
  11. Iacchus

    Iacchus God of the Mask

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    The only flaw I see in the theory of evolution has to do with man, and just what the heck it is he's doing here? For of all the creatures on this planet he's the only one that seems incapable of living in accord mother nature. And rather than show any adaption evolutionary wise, for example a beaver develops a broad tail to swab mud, he shows a total disregard for his environment while getting nature to succumb to his every whim. Does that even sound close to living in harmony with nature? Not even the apes, our nearest relatives, are capable of perpetuating such a legacy. In fact there's nothing about them to suggest they live outside of the constraints of their environment.

    So, is it possible that there's any merit to what the book of Genesis says, that man is a fallen creature which, as a consequence, puts him at odds in an environment where he doesn't belong? Whereas before the fall, he was given complete ascendency over the earth but now, he's continually at odds with it. Doesn't that sound the least bit plausible? :)
     
  12. gluadys

    gluadys New Member

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    Thanks for the intro to a new forum. I posted an answer there, but for the benefit of folks here, I'll post it here as well.

    The flaw is not in the theory of evolution, but in one of your assumptions: that all non-human creatures live in harmony with nature. They don't necessarily. They don't so much live in harmony with nature as adapt to their environment. If the environment changes, they need to re-adapt, and often they don't. Then they become extinct. Only 1% of all known species are currently alive today. The rest failed, at some point, to live in harmony with their environment.

    Humanity has achieved a level of mastery over nature that has enabled us to avoid some of the hazards of environmental change. With technology we have found ways of living in virtually every terrestrial habitat, and may one day go beyond that.

    Yet in spite of that mastery, we are not totally free of natural constraints.
    Five times in the history of the earth, an event has triggered a massive extinction of many species. Now a sixth is underway and the triggering event is US! Humanity and its careless exploitation of natural resources.

    If we get smart enough, fast enough; if we care enough, we can stop before irreversible damage is done.

    If we don't, it is entirely possible that one of the species whose extinction we ensure is our own.

    Either consequence is perfectly compatible with evolution.
     
  13. iBrian

    iBrian Peace, Love and Unity Staff Member

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    Thanks for posting it here. :)
     
  14. juantoo3

    juantoo3 ʎʇıɹoɥʇnɐ uoıʇsǝnb

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    Kindest Regards, gluadys!

    I wanted to take a moment and let you know I am researching a response. I have gone through a lot of information, but I have a great deal more to go through yet to post a proper reply.

    This had to do with fruit flies remaining fruit flies, meaning that they are still generally capable of "interbreeding." At some point, the "evolved" species is no longer fruit fly, at which point I would be satisfied the qualification of distinct speciation would have occurred. That is the basis of my comment, which I hope resolves the red herring.

    Granted. Isolation, for example, can cause species to adapt. Some of the material I covered demonstrated where isolated "species" were artificially reintroduced and began hybridizing. This is not "true" or possible in all instances, but there are enough "exceptions" to give pause in consideration. I do not have my research in front of me to properly quote, but one example that stood out to me was that of the wild horse mating with the domestic horse, and producing viable offspring, even though the wild horse has two more genes than the domestic.

    I did go here, and I printed out some information, which I will go through when I can.

    I haven't read Darwin yet. Mental block, I'm sure. Perhaps one day. If I recall my high school biology class, Mendel was the monk who raised petunias to demonstrate genetic disposition (dominant and recessive genes). I also recall reading somewhere that he also fudged an awful lot of his data to make his point. My point being that "recessive" is not necessarily "submissive", perhaps just unexpressed individualization.

    Controlled hybridization has produced many of the domesticated varieties we are familiar with. I cannot refute your comment, but selective breeding has served humanity well over the course of 4 to 5 thousand years of agriculture and animal husbandry. Left to their own devices, what you say about reversion is true. Yet, through selective breeding, as explained by the teacher in the aforementioned biology class using a mathematical model that I do not fully understand, he explained that a new "breed" could be created after something like 12 generations. Even after only 6 generations, the preferred genetic disposition was the dominant expression, provided the breeding stock was carefully selected and controlled. In effect, this is how the various breeds of dogs and cats were and are bred, as well until recently the majority of agricultural crops and livestock.

    Certainly. This is the mechanism used throughout nature. The example that immediately comes to mind is the blind cave fish. I don't know what stock it comes from, but the supposition is that after being trapped in a dark cave they lost the need for sight, so their eyes degenerated and now they no longer have the capacity to see. This is an adaptation, as presumably they have acquired other means to navigate (they do well enough in an aquarium). I do not know if they can mate with the parent stock.

    The example I looked at concerning a weed in England specifically pointed out a natural hybridization between two "native" or "naturalized" (related) species. Another example, controlled, crossed a radish with a cabbage (in Russia). The result was not worthwhile, producing the leaves of the radish with the root of the cabbage, but the two were distinct and unrelated species (or at the least not anywhere near closely related, radish is not in the brassica family).
    While natural hybridization may not be the prevalent form, it does occur.

    Another collection of information I looked at considered the development of the domestic dog from wild stock. After considering wolves, dingos, hyenas, coyotes and foxes, the research concluded that domestic dogs came from 4 distinct lines of the wolf, from different places in the world. The influence of the coyote and the others was dismissed by the conclusions. And the 4 lines of wolf are distinct, and at best only very distantly related. It was also concluded that fresh influx of "wild" blood from time to time came back into the domestic lineages. But, as far as I know, other than the problematics of size, all dogs are capable of interbreeding.

    Actually, I think I have Vajradhara to thank for pointing me to the bulk of the information I have presented to this point.

    You are correct, brassica is the scientific latin nomenclature. Cole is the colloquial nomenclature. I am not incorrect. Check the Old Farmer's Almanac or Organic Gardening or Mother Earth News.

    This dealt with sterility. And yes, it is a common problem with hybrids. Yet some of the research I looked at concluded that even among typically sterile offspring, it is quite common for an occasional virile offspring to occur. I concede that "occasional" is not conducive to natural selection, certainly not to abundant regeneration, but it does occur naturally. Adaptation and individualization.

    All life shares genomic traits. Which is why deliberate genomic interference can occur in a laboratory setting. Which is why jellyfish can be deliberately mixed with rabbits, flounders with strawberries and tomatoes, bacillus (sp?) thurigensis with corn, and radishes with cabbages.

    That is why she is kept under wraps, to keep her from accidentally introducing the genomic manipulation into the natural system.

    Some of the examples I looked at demonstrate this, like creatures stranded in an island environment, adapt to their surroundings (or perish, in which case we would not be discussing them). Some of them do change, very quickly, in the space of a very few generations, such as the English moths. This isn't hard to recognize when one sees the inherent differences in specific individuals. We would tend to look at moths as being moths (they all look the same to me...), but each individual has subtle differences. Like humans, short/tall, thin/stocky, fair skin/dark skin, fine hair/thick hair. Sorry for the shift in example, but I am not familiar with dissimilarities in moth populations. If a specific trait shows an advantage in survivability, that trait becomes more dominant in the gene pool of that species. Like changing color from light to dark in the case of the moths. There always were dark individuals, but they were the minority in the population prior to the industrial revolution. Against the soot that built up on everything, the light moths stood out and became better prey. The dark colored ones gained ascendency not through change per se, but through a greater percentage of dark color being able to survive in the new environment. Adaptation, but both colors were already in existence in the population, before and after the transition stage.

    Another consideration occurred to me, thinking of humans. The races are quickly becoming one. A poet and frequent guest speaker on PBS, Richard Rodriguez, pointed out a few months ago what he calls "the browning of America." As we become more racially tolerant and intermingled, we are becoming more the same. Yet I thought evolution was the divergence of populations? Perhaps an isolated circumstance, but considering it directly involves humanity, it is an exception worth great consideration. (LOL, evolution meets anthropology through philosophy!)

    Yes, but that distribution is throughout the species as a whole, at least in the case of the moths. The differing alleles were already distributed, as individualizations, throughout the population, in greater and lesser quantities.

    Then why does a fruit fly remain a fruit fly? The herring has changed color. If it became a distinct "other", it would be an evident "species," but as long as it remains a fruit fly capable of interbreeding, it is merely an adaptation. Choosing not to interbreed given choice, might lead as you indicate, at which point I could humbly concede. Even in looking at the fruit fly info, the choice not to breed with the parent stock was not the indicator, it was a differentiation or individualization that was highlighted in a specific population. In limited populations, I seem to recall a reversion to interbreeding with the non-preferred species, although I will be hard pressed to find that in the info.

    The balance of the conversation dealt with crocs and turtles, and I printed that material out just today and haven't had the oppportunity to go through it with any detail. The croc line, I did read, was the predecessor to and ancestor of one of the major lines of dinosaurs, and yet managed to outlive an entire evolutionary branch? The mega-crocs died out, but the several species composing today's crocodiles, alligators and caimans, is largely unchanged since long before the dino-extinction, something like 120 million years ago. These are the creatures supposed to have made the transition from water to land, some of the original amphibians.

    Thank you very much for your input. You have made me do my homework. I am still having trouble accepting the establishment doctrine concerning evolutionary theory, and there is much more that impinges on that mental outlook. Adaptation is a viable and recognized and demonstrated act of nature. Crossing the boundary from one species into another is not demonstrated to my satisfaction, at least not in the sense of not being able to interbreed.
     
  15. Quahom1

    Quahom1 What was the question?

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    When a Horse breeds with a donkey, the result is a Mule. Strong, smart, loyal, steadfast, mortal. The Mule cannot reproduce, Therefore its generation is the only generation. My point is that some things just cannot be, no matter how hard we wish them to be. Some things can evolve, and some things cannot. Some thing have evolved, and some things have not. Where oh where is Man in this story?

    v/r

    Q
     
  16. juantoo3

    juantoo3 ʎʇıɹoɥʇnɐ uoıʇsǝnb

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    Kindest Regards, Quahom1!
    Yes, sterility in hybrids is sometimes an issue, as we covered in an earlier post specifically noting mules. But I also found information concerning a wild horse (with a very unfamiliar and difficult to pronounce name) that is able to interbreed with domestic horses and produce viable offspring, despite the fact that the two have a different quantity of recognized genes, 64 for horses and 66 for the wild horse. This is also demonstrated in the equine races, reaching way back in my memory, to the quagga, an extinct shaggy zebra that died out around 1900. With the events in Iraq over the last decade or so, I haven't heard what became of the research, but there had been an attempt to extract the quagga bloodline from a line of zebras kept at a zoo in Iraq. An attempt was being made to rebirth a lost species. This could only have been conceived and undertaken if it was understood that the bloodline was contained in the hybrid form amongst those animals. And that through selective breeding it could be extracted.

    Moving on to livestock, what of the bovine breeds? Is a buffalo too closely related to a heiffer? They definitely spent an awful lot of time isolated from each other in different ecologies, yet beefalo is a hybrid (in fairness, I don't know what breed buffalo are crossed with; but like dogs, bovines are pretty much interbreedable in my understanding). Or brangus, the brahma/angus cross. Scientific speculation is a wonderful tool for conceptual purposes, thinking out how things might work, then reality must set in. There are some real world examples that seriously challenge many of the notions that are espoused in the classroom as inescapable fact.

    "Demonstrating that a population is reproductively isolated (in a nontrivial way) from populations that it was formerly able to interbreed with shows that speciation has occurred. In practice, it is also necessary to show that at least one isolating mechanism with a hereditary basis is present. After all, just because a pair of critters don't breed during an experiment doesn't mean they can't breed or even that they won't breed. Debates about whether a speciation event has occurred often turn on whether isolating mechanisms have been produced." -Observed Instances of Speciation, by Joseph Boxhorn, Copyright © 1993-2004, (emphasis mine)

    As for "Some things can evolve, and some things cannot. Some thing have evolved, and some things have not. Where oh where is Man in this story?", man has an intimate part to play in this puzzle. Humans have been artificially selecting breeding stock for millenium, for the purpose of producing better quality and quantity of foodstuffs, livestock, draft animals and companion animals. A great deal of this has been through hybridization that has been viable.
    Another take on your question is semantical. What is considered a "species" to one, seems to be equally considered too closely related by another, relegated to the status (loosely) of breed or variety. A breed is not necessarily a species, I am learning. Yet, when a fruit fly breed is held out as a species, by some of the same people who claim breeding incompatibilty as a prerequisite for speciation, I am confused over the semantic conundrum. When a chihuahua chooses not to mate with a great dane, are they then different species, or breeds?

    This can even be carried a step further yet. What then, of humans? If the bonobo is so closely related to humans, having spent as much effort in evolution, why are they so undeveloped in comparison to ourselves? Why have they no speech? No fire? No sharpened implements? No stone tools? Why are they not walking out of the jungle to take better control of their world? What a difference 3-5% of the genomic string makes!
    I can't find the direct quote just now, but Francis Collins has said (paraphrased), "There is only a difference of a few hundred genes between a mouse and a man. But you cannot replace those genes in a mouse and expect it to begin playing golf or listening to Mozart." The point being, there is a great deal of focus on genomic quantity of apparent matches, with little to no real attention being made (yet!) to the quality of the apparent matches. I suspect this is because a lot of the tools for doing so do not exist.

    One could extend the bonobo concept to Neandertal, who many believe to have excelled Cro-magnon in brain size and physical stature and strength. Yet, Neandertal died out, and Cro-magnon ascended. It is now believed the two were supposedly different species with common ancestry, yet they exhibited compatibility with each other. There are finds that demonstrate social interaction between them. How far this cooperation extended is still open to question, but for this discussion were they able to interbreed? If so, then they were not individual species? If not, did Neandertal keep our relatives as pets (like we might a monkey or dog)? There are some serious issues that can develop on this subject, that can affect and influence our outlook on life, society, religion, psychology and a whole gamut of other matters that affect us all at the core of our being.
    In this, religion may be a gross oversimplification (according to some), but I view it as a very necessary one, without which we would never have grown past the animal stage. I am of the opinion that that "revelation" came to humanity in a moment, it was handed directly to us with purposeful intent.
     
  17. gluadys

    gluadys New Member

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    I can't tell you what a pleasure it is to meet someone who is acutally willing to do research!!

    So often those who raise questions on evolution merely rant and run.

    What we are really dealing with here is the imprecision of common names. More often than not common names refer to higher taxonomic orders that species.

    Consider this list: platypus human rhinoceros, rabbit, beaver, armadillo, spider, frog, bat, worm.

    Of these, only the platypus and the human are a single species (and then only if you count living species). There are three species of rhinoceros. The common name then refers to a genus. Rabbit, beaver and armadillo refer to all the species in their respective families. (There are at least 7 different genera of armadillo). Spider, frog and bat each refer to thousands of species in the same order. And worm is a name applied to species in several different phyla. Some worms are more closely related to spiders than to other worms. Some are more closely related to us than to other worms.

    "fruit fly" refers to any of 3000 different species in the Drosophilidae family. So just because they are called "fruit flies" or "rabbits" or "frogs" does NOT mean they are capable of interbreeding.

    And asking for a new species of fruit fly not to be a fruit fly is asking for a level of saltation not found in nature, for you are asking for much more than a species change. You are asking that the new species be not even of the same genus or family as its parent species.


    No question but the examples in a high school text are very basic and simple. In real life genetics is much more complex.

    Right. What the breeder does is control the selection process and maximize the selection pressure toward the preferred characters. It can be a very rapid process indeed. One of the things that Gould and Eldredge did was to show that quite rapid evolution is also found in nature. They called spates of rapid evolution "punctuations".

    Strictly speaking, evolution is simply an inherited genetic change in the distribution of characteristics in a population. So the changes in the distribution of melanin producing skin cells due to greater racial mixing is evolution.

    If we were to apply the strict racial separation that the supporters of apartheid tried to in South Africa we would no doubt get greater racial diversity instead of homogenization. But as long as all human races live in and adapt to a wide variety of habitats, it is not likely we would get separate species. To get a distinct human species in the future it would probably be necessary to isolate a group of colonists on another planet. That would provide a distinct environment they would have to adapt to.


    Keep up the research. Remember it is not appearance which determines whether or not individuals are of the same species, but ability and willingness to mate and reproduce. Sexual selection (willingness to mate) is an important factor in establishing new species.

    Sometimes a change in appearance initiates sexual selection and isolated breeding groups. In other cases the isolation occurs first and changes in appearance occur later. So the key is not what the populations look like or what they are called, but what they do. Do they interbreed or not?

    There are several instances in which the evidence is quite conclusive that new fruit fly species (i.e. groups which no longer breed with the parent stock) have been established. Here are two:

    Insects that live on a single host plant provide a model for sympatric speciation. If a group of insects switched host plants they would not breed with other members of their species still living on their former host plant. The two subpopulations could diverge and speciate. Agricultural records show that a strain of the apple maggot fly Rhagolettis pomenella began infesting apples in the 1860's. Formerly it had only infested hawthorn fruit. Feder, Chilcote and Bush have shown that two races of Rhagolettis pomenella have become behaviorally isolated. Allele frequencies at six loci (aconitase 2, malic enzyme, mannose phosphate isomerase, aspartate amino-transferase, NADH-diaphorase-2, and beta-hydroxy acid dehydrogenase) are diverging. Significant amounts of linkage disequilibrium have been found at these loci, indicating that they may all be hitchhiking on some allele under selection. Some biologists call sympatric speciation microallopatric speciation to emphasize that the subpopulations are still physically separate at an ecological level.

    http://www.talkorigins.org/faqs/faq-intro-to-biology.html

    Fruit flies do not remain the same species of fruit flies. Drosophila melanogaster populations evolved reproductive isolation as a result of contrasting microenvironments within a canyon [Korol et al. 2000]. We would not expect to see much greater divergence in historical times.

    References:
    Korol, A. et al., 2000. Proceedings of the National Academy of Science USA 97: 12637-12642. See also Schneider, C. J., 2000. Natural selection and speciation. Proceedings of the National Academy of Science USA 97.

    http://www.talkorigins.org/indexcc/CB/CB910_1.html

    Complete article

    http://www.pnas.org/cgi/content/full/97/23/12637


    That's correct. And the dinosaurs were a very successful branch---several sub-orders and a total span of 160 million years.


    Unchanged in what way? Certainly they are still part of the same reptilian order. But are they still the same species? Or even the same genus? Do they still have exactly the same characterisitics in all respects? I expect that if you check into crocodile history in more detail you will find there are significant differences between Mesozoic and modern species in the crocodilian order.


    Well you certainly need to do some homework in basic taxonomy!!. Crocodiles are reptiles, not amphibians. (Crocodiles, though they spend much time in water have to come to land to lay their eggs. By contrast, even amphibians which spend most of their time on land need water, or at least a damp place, in which to lay their eggs as their young are born as tadpoles. Crocodiles lay an amniotic egg enclosed in a shell. Amphibians lay a jelly-covered egg, much like those of a fish.)

    There is no doctrine of evolution as evolution is not a religious outlook. There is a theory of evolution which has a great deal of evidential support. It does help a lot to be clear as to what exactly the theory does and does not say, and I appreciate that can be difficult as the religious zeal to attack the theory has led to a great deal of mis-information being widely available.

    Precisely what do you mean by "crossing the boundary from one species to another"? If there are two existing species reproducing separately, you will not find a parent in one group producing offspring that belong to the other group. Never. The best you could get is a hybrid of the two. And there are documented cases in which such a hybrid has proved fertile and become established as a third species which does not interbreed with either of its parent species.

    Such hybridization is one way to get a new species, but I would call that crossing from one species to another.

    The other way to get a new species that we have discussed is through population isolation. A single species is split into two species. This has also been documented both by experiment and in nature. And I don't think that can be called crossing the boundary either. It is more in the nature of erecting a boundary where there was none before.

    The other way for a species to change is by phyletic gradualism. This is a gradual accumulation of changes in one species such that the species at the end of the transformative process is different from the initial stock. When phyletic gradualism occurs over time, it has to be inferred from the morphology of fossil sequences as one cannot directly test whether the newer species could or could not interbreed with the ancestral species. But we also see examples of phyletic gradualism in which all the gradations from one species to another are contemporaneous. Such sequences are called "ring species".

    "The Arctic Ocean polar ice cap limits the species range of Sea Gulls to its periphery. Races from Siberia freely interbreed with races from America. Races from America freely interbreed with races from Europe. Going the other way, Races from Siberia freely interbreed with races from the Caucauses. However, Western European herring gull (Larus argentatus) do not interbreed with the lesser black-backed gull (Larus fuscus) from Centrial Europe where these races of Sea Gulls occur together in northern Europe. So, all along the ring that circumnavigates the globe about the Arctic there is gene flow but where the two ends of the ring meet in Europe there is no gene flow."

    http://geowords.com/histbooknetscape/f26.htm

    This is the closest example I can find of "crossing the boundary from one species to another" yet that description doesn't really seem to fit here either.

    I don't know of any other way that new species evolve, so perhaps you are barking at a bogeyman that doesn't really exist in nature.
     
  18. gluadys

    gluadys New Member

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    When things cannot evolve in response to a new environmental challenge they become extinct.

    So long as a species is not extinct yet, it CAN evolve. That doesn't necessarily mean it WILL evolve. There is no living species on earth today which has not evolved. That includes humanity.

    By the way what is Man? Why the upper-case letter?
     
  19. gluadys

    gluadys New Member

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    What examples do you have in mind here juantoo?

    It is very important to remember that evolution relates to species i.e. to populations, not to individuals. So we need to break down your question into more than one question.

    1. If my pet chihuahua chooses not to mate with my neighbour's great dane, are they different species? Not necessarily. My pet chihuahua may just be finicky.

    2. If chihuahuas in general choose not to mate with great danes in general, are they different species? Possibly. If they were the only breeds of dog in existence we could predict that this sexual preference on the part of chihuahuas would lead to them becoming separate species if they are not already.

    3. If chihuahuas are physically incapable of mating with great danes (and I believe they are), are they different species? They certainly would be if they were the only two breeds of dog.

    What prevents us from calling chihuahuas and great danes different species is the existence of other breeds of dogs, some of which can breed with chihuahuas, and some of which can breed with great danes, and which also breed with each other. So even if chihuahuas and great danes cannot interbreed directly, there is still an avenue of gene flow from one population to another via the intermediate breeds. This situation is analogous to a ring species, though I don't know that biologists would apply that term to dogs.

    Remember, evolution is not an assembly line which is carrying all species in the same direction. Humanity is not a model which other species are trying to emulate, nor a goal they are striving to reach.

    Bonobos don't speak because the position of their larynx is different from that in humans. This makes the pharyngeal area less flexible and unsuited for the fine-tuned production of sounds needed for speech.

    They are capable of understanding speech and learning sign language or other substitutes for speech.

    They do make and use tools, but do so on an ad hoc basis. They appear not have the intellectual capacity to plan tool use long in advance of need to use a tool.


    Cro-Magnon did not "ascend". Cro-Magon is an early homo sapiens culture which appeared in Europe about 25,000 to 30,000 years ago. Cro-Magnons are no more different from you and I than Germans or Brazilians. Not a different species at all. Just a different culture, like Egyptian or Babylonian.

    And, more to the point. Evolution should never be thought of as "ascension". Evolution is not a process of ascending a ladder. It is a process of radiation into different ecological niches. No one ecological habitat makes a species more "ascended" or "evolved" than another.

    Whether they were able to or not, the latest information suggests that they did not. This may lead to reclassifying neanderthals as a separate species rather than sub-species.

    There is no question that the neanderthals had a cultural and spiritual life, given the artifacts found with them, including their burial practices. But they did not develop the artistic expression of even the earliest known sapiens such as the Cro-magnon. They left us, for example, no cave paintings or artistically decorated tools.
     
  20. juantoo3

    juantoo3 ʎʇıɹoɥʇnɐ uoıʇsǝnb

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    Kindest Regards, gluadys!

    AH, thank you! Now I see a bit of light! I think I understand a little better the distinctions now. Please bear with me as I integrate this new understanding (I am liable to slip and revert to familiar understanding).
    Now I think I better understand the red herring comment. Yes, I would expect a new species of fruit fly to remain in the fruit fly order, I would not expect it to become, say, a lizard. I am not finished with the material, and it may take a little while (I printed out probably 500 or so pages of information), but in some of the material I did go through, "different" fruit flies were able to interbreed. At least, that is what I understood the material to have said.

    I will have to address the rest another time. It is way late, and I'm muddling on mentally. G'nite! and thanks for the reply!
     

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