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Author | Topic: The egg came first | |||||||||||||||||||||||
Parasomnium Member Posts: 2228 Joined: |
Cal,
Welcome to the fray. You seem like a valuable addition to the debate: only eleven posts (at the time I write this) and already you've managed to strike up an meaningful conversation with Brad. Also, you are an excellent writer, it seems. So, once again: welcome.
Cal writes: I dream of a world in which it is as easy to strike up a conversation with the common man you meet on the street about protein folding or transposons as it is to get him talking about football or baseball or hockey. I think you may have found your street. It's called EvC. We are all atheists about most of the gods that humanity has ever believed in. Some of us just go one god further. - Richard Dawkins
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crashfrog Member (Idle past 1717 days) Posts: 19762 From: Silver Spring, MD Joined: |
If, as you say, a child cannot be of a species different from its parent, then how could we possibly evolved from an ancestor that also led to chimpanzees. French evolved from Latin, to the point where a speaker of French cannot meaningfully communicate with a person who speaks only Latin. That change happened over successive generations of language change. Nontheless it does not follow that one of those speakers of Latin had a child who spoke only French.
Indeed, if as some say, all life can be traced back to the first primitive life with DNA, then to have a descendant of a different species seems to be required. A decendant, certainly. That does not neccessitate that a parent had a child of a different species. You're asserting that the line is arbitrary and fine; I'm asserting that the line disappears when you look closely at it. It's like the old question "when is it raining?" If a lot of raindrops are falling on your head, it's certainly raining. If one drop falls all day, it didn't rain. So how many drops constitutes rain? 10? 100? It's meaningless to try to say. The "line" is not a line at all, but a gradiation. It's fuzzy, and there's no way to say exactly when you've crossed it.
Seems to me the numbers should be 99% chicken and 100% chicken. Even chicken isn't 100% chicken. You're getting back to species essentialism. If I have two chickens, and they have slightly different characteristics, which one of them is the "more" chicken? Species essentialism is the doctrine that all organisms of a certain species are deviates from some Platonic, perfect species "essence"; that the varation among individuals represents the corruption of some perfect ideal member of that species. Species essentialism is disproved, of course, by evolution, but it's often implicitly invoked by creationists when they speak about "kinds". You're the first evolutionist I've met who implies species essentialism, though. To say that something is 99% chicken implies that there's some kind of chicken "essence", or a specific configuration of characteristics that means "chicken." That's species essentialism. Organisms are 100% themselves, not part-chicken or part-ape. And the species that they belong to is determined by the population with which they share gene flow, not the essence of which they are an imperfect copy of.
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bkelly Inactive Member |
quote: I am not certain what to say here. From my understanding of your statement, I do not buy into species essentialism. A chicken can be all white, all brown, all any shade in between, or an indefinite combination. It can be short having nothing but short immediate ancestors and descendants, or tall in the same manner (relatively speaking that is). But I would not say that any one exact chicken epitomizes all chickens. There is a broad range of chicken. I think that here is a communications disjoint. (I say disjoint because to me “problem” implies something is wrong and the error will be on one side or the other.)
quote: I agree. I went through a phase of coining aphorisms, one of which was: “There is no fine line of distinction, its always fuzzy and grey.” My favorite example is the photographers grey scale card, black on one side, white of the other, and it gradually changes from one to the other. At no point on the card can one say that this side is white and the other black.
quote: From my reading of this, you did not respond to the essence of my statement. The only way to get from a single species, the first life that existed, to today’s myriad of species, is for one species to begat two or more descendant species. This fact seems to completely refute your position.
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Brad McFall Member (Idle past 5283 days) Posts: 3428 From: Ithaca,NY, USA Joined: |
There is some error in the lack of reply buttons to cals posts so I ma reThere can be no doubt that von Baer won his greatest fame through the embryological works written in his youth. He published the results of these in a brochure entitled De ovi mammalium genesi, which came out in 1827, and a larger work, Uber Entwicklungsgeschichte der Tiere. of the years 1828 and 1837. In the first-mentioned treatise he describes the most important of the discoveries he made in this field - namely, the egg of mammals in the ovary. Apart from the vauge ideas of earlier scientists on this subject, de Graff (Part II, p. 172) was the first to explain at all the conditions obtaining at the earlies stages of development of mammals. He described the follicles named after him in the ovary and believed these to be eggs; when later he discovered eggs in the uterus of a rabbit in a later stage of growth, he supposed that these had moved thither from the ovary for their further development; he met with an insoluble difficulty,however, in the fact that the further advanced uggs in the iterus were smaller than the follicles, and moreover, the latter proved to be not very constant, wherefore Haller, who carefully investigated matter, assumed that the egg was formed out of the follicular fluid through coagulation. By carefully following the development of the egg in dogs, von Baer learnt to know its later stages, afterwards tracing its origin back by investigating a series of animals approaching nearer and nearer to the fertilization stage. Here he found the egg to be a minute yellowish cell inside the follicle, after which he was able to continue the study of its progressive development.[/quote] THE HISTORY OF BIOLOGY A Survey Tudor Publishing 1928. by Erik Nordenskold p363-4
Well in the 90s I was “sucking ovaries”, removing mammalian eggs from dead cows’ follicles and keeping them alive with sterile techniques. I then added sperm. Some of the cells became blastocysts. What does it mean? Is this the same thing as artificially pollinating day lilies which I also did a two years ago, creating hybrids? Well I can not answer the second question because I don’t think that A:“eggs cross the road to get to the other side” is the same thing asQ:” which came first, the chicken of the egg?” By equating them you reversed something. Let’s see if we can see what it was. Nordkenskiold quite textually and VERY Clearly associates the “adult” issue with inability to notice the difference of the follicle and cell in it’s” insides”. With birds we do not have this problem. We see the NEST as well as the egg, no matter that it is an ovary rather(that) we were speaking about, since you lumped my seed and the egg into a single responsive post. So it does matter to some extent that one can remove one’s mammalian bias when discussing strictly the duky problem you got but not I, in your syringe. I will think about snake lipids going through the skin instead of any rejections of the follicle or let me say Mendel’s binomial across these generations’ generation. The thing is that even in 1990 based on results of the 1950s animal physiologists completely misread the total literature, for they fail to appreciate that the PHYSICAL ACT of follicular release may well be causal and determinative no only for what are the “later stages” of evo-devo but also for variation in the phyletic use recombinations of growth and development retain whether silencing transposons or not. There, do your feminisms if you desire. Let me say that again, what N said textually is physically at issue , if one tries to think whether said egg or later staged individual came first (no matter the difference in ontogeny or phylogeny). There is complete lack of realization on the part of animal physiologists that the egg’s relative position to the follicle to the ovary to the female to the niche to the mother earth etc could be absolute. It is assumed it is only relative to the chemical melilue, gene expression environment, phylogenetic position etc. So if we have this much problems imaging what it is like for kinds close to us, I had my son, when doing this work, imagine what it is for a pea?? Or don’t, since you think they are the same answers. The questions at least are different. This is my last word until Cal answers something.
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Brad McFall Member (Idle past 5283 days) Posts: 3428 From: Ithaca,NY, USA Joined: |
They were YOUR words. I wouldnt have written as much if you didnt care. Which you seem to not. And NO it does not matter as to the "species" it only matters as to the seperation ON earth of the garden and the country. Species"" might as well be what a German matriarch puts in the soup. Species being a class MIGHT be used but then you are immediately open to creationist criticism no matter what kind of Kitcher your math enables etc.
These were mine.http://listserv.nhm.ku.edu/cgi-bin/wa.exe?A1=ind0103&L=ta... http://listserv.nhm.ku.edu/cgi-bin/wa.exe?A1=ind0102&L=ta... Find the first in this series and you find where i intro DUCE on-line the idea of such an index This message has been edited by Brad McFall, 09-17-2005 07:46 PM
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crashfrog Member (Idle past 1717 days) Posts: 19762 From: Silver Spring, MD Joined: |
From my understanding of your statement, I do not buy into species essentialism. No, I didn't believe that you did, of course. But it does seem like what you're arguing, which is why we're having this discussion - to see if it's merely that I don't understand your argument, or you haven't entirely thought through every last implication of it.
At no point on the card can one say that this side is white and the other black. Indeed. And, while it's certainly the case that the decendant of the modern chicken was a red junglefowl, at no point did a red junglefowl give birth to a chicken; at no point can a parent be said to have given birth to an offspring of a different species. There's certainly a line between the red junglefowl and the chicken where organisms on this side are junglefowl and organisms on the other are chicken; but it's impossible to determine where this line lies. You can, perhaps, assert the probability at each point of you being on one side of the line or the other.
The only way to get from a single species, the first life that existed, to today’s myriad of species, is for one species to begat two or more descendant species. This fact seems to completely refute your position. No, it doesn't, for the reasons that I said, and that I illustrated via the analogy you just dismissed. Even though species beget new species, that doesn't in the least imply that a parent has offspring of a different species; which as I've explained would be a situation completely incoherent with the definition of "species" as a reproductive community. The only way a parent can issue an offspring of a different species, of a different reproductive community, is if the offspring's genes came from some other source - surrogate parenting via in vitro implantation, if you will. Since this was certainly not the case among the organisms in question, we know that there's really no organism among the ancestors of the chicken that we can point to as "the first member of species Gallus gallus". At least, that's the way it seems to me. We know that a speciation event occured, obviously; nontheless it seems impossible, or at least incoherent with the idea of species, to try to point to one or another individual as the one to whom the event "occured."
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Cal Inactive Member |
Brad,
Although I continue to experience some parsing difficulties (missing referents seems to be a lot of it) I find your contributions fascinating. You appear to have a mind that simply leaps at things, even if the intermittent placement of the resulting footprints does make tracking you somewhat tricky. I feel that I have good reason to hope to learn much from your contributions -- and much perhaps as a result of my attempts to express my reasons for disagreeing with you, when I do. Which may be often. But while I expect to continue to find much in your posts to which I would like to respond, I do not want to do that in a hasty manner. I'm afraid I may already have done that, and now have cause to regret it. (Some days, if I go a dozen posts without giving myself some reason for apologizing, I'm doing good). I apologize for so casually waving away the value of whatever effort you'd care to make toward "explaining how the egg could be singled out of the population". It was rude. I admit, I don't think you can do that (certainly not in the way implied by the most literal interpretation of way the chicken/egg question is framed) and I still have a hard time regarding the question as anything but silly and trivial. But I've been wrong before. I'm willing to try my best to set aside my bias if you're willing to try to make your case a little more intelligibly. I'm not sure I can set aside my bias long enough to enable me to hunt down all the places you've presented the argument before (things I consider important, I try to keep well organized and close at hand, but maybe that's just me). It's up to you to decide whether you think it would be worth the effort. If not, no hard feelings, honest. Maybe some other time. Maybe dole it out in bite-sized pieces. Whatever. Might go smoother anyway once my 'Bradspeak' has improved enough to give me a better chance of grasping the full meaning of phrases like: "So it does matter to some extent that one can remove one’s mammalian bias when discussing strictly the duky problem you got but not I, in your syringe." I hope you won't feel pressured to respond yourself. I mention this because some of your posts look like they were composed in a hurry; if so, this may be a factor contributing to some of the trouble I (and, apparently, some others) have in following you. I'd like to reassure you that I'm not going to suddenly lose interest. You are obviously very dedicated, and whether I agree with you or not, I have great respect for that; but the conclusions you reach are only worth as much as your ability to communicate them. If you do decide to proceed, take your time. I'll be here, even if it's just to read. (I hope you won't take offense at this suggestion, but if you'd take a little more trouble with spelling here and there, I think that might help a lot). Naturally, if what I'm seeing is simply the posting style you're comfortable with, then of course please don't give another thought to what I think. I was delighted by your statement: "I wouldn't have written as much if you didnt care", because I was thinking much the same thing. Even if you fail to persuade me that the chicken/egg conundrum (about which I've already said much more than I would have if not for your involvement) can be (or needs to be) solved, I will still look forward to trying to figure out what the heck you're talking about on questions I do regard as more deserving of the attention.
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Brad McFall Member (Idle past 5283 days) Posts: 3428 From: Ithaca,NY, USA Joined: |
No, I do not feel "pressured" to respond. You measured return is well taken, at least by me.
It seems to me that you are categorically not thinking that a hierarchicalization of biological information enables me to have responded prior to the already old 'apology'. What I had at last presented was a clear delineation of a level of organization issue that CAN NOT be a level of selection problem. If we need to do some philosophy of biology here we can. I am not using Cornell's library lately so I can not easily run and pull off the relevant titles from the shevles very fast as I used to be able to do. I tried to demonstrate the a "coagulation" can be better refined by indexing masses at worst quantum mechanically and that thus in the SELECTION of these non-spheres one attained in a hierarchical expansion of current evolutionary theory not merely a way to remark on the development but also grow the class the species would likewise name. It might be best if we await another opportunity. I have no pretension to "change" Parasomonium's mind nor yours. It is fully logical to reject what I am proposing after reading how it might be worked out in detail if you suppose perhaps with Richard Dawkin's that no matter what the hierarchicalization is, it will always only be the account of the genes involved that counts. I dont believe in such a reconciliation. I believe and write on EVC that the philosophers of biology have not analyzed far enough. It is like the mathematician magician who recently came to Cornell and using rules of binary threes could guess probabilistically who held red cards randomly distributed to the students and thinking thusly that manipulation of the genetic code that way is as far a nanotechies will ever get realistically. I just think on a much more divided grid. I do not think that Mendel's concern for the taxonomy of the pea plants matters one track in this probabilistic decomposition that I attempt not only to analyze but also synthesize. One would start but not end with the phenetic approach. As Croizat said, taxonomy is the last but not the least occupation of the biogeographer. Phenetics and indexing is the first of the last. People have a hard time thinking past that.
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bkelly Inactive Member |
quote: In the genus Canis there are a number of species to include several species of wolf, coyotes, wild dogs, and others. While I am not positive, I am quite certain that many of these can breed between species. The offspring must be of a different species from at least one of the parents. On the other hand, it seems to me that the fowl that is 99% chicken, and the fowl that is 100 % chicken can be of the same species. We could line up a progress of descendants from one animal, such that each individual differs from its parent by some amount, but not enough to declare the individual and its parent of two different species. Yet if with compare the earliest animal with its 1000th generation descendant, they may well be different species. Again, we are back to the fuzzy line. No matter where we go and what we do, we will always be drawing arbitrary lines. That’s just the way life is. The whole point of the question was to focus on the union of sperm and egg. This is the point where inheritable characteristics differ. This is the identifiable point of evolution on the scale of the individual. I say this not with inarguable clarity and undeniable fact, but in general terms and concept: The egg came first.
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crashfrog Member (Idle past 1717 days) Posts: 19762 From: Silver Spring, MD Joined: |
While I am not positive, I am quite certain that many of these can breed between species. They can, but they don't. There's no significant gene flow between these populations, which is why they're different species.
The offspring must be of a different species from at least one of the parents. I don't believe that hybrid animals are even classified as species, particularly since they don't form populations. But I could be wrong. Nonetheless you raise an interesting point.
On the other hand, it seems to me that the fowl that is 99% chicken, and the fowl that is 100 % chicken can be of the same species. I guess my original point was that it's not clear to me how you can say "99% chicken" without implicitly invoking species essentialism. A bird is not a chicken because it has a certain number of chicken parts, although that morphological criteria is how we recognize species, for the large part; a bird is or isn't a chicken based on the degree to which the bird is part of a population that experiences significant gene flow with populations of chickens.
The egg came first. Depending on the mechanism of chicken speciation, I'm not sure that I agree. Or that it can even be decided. If a population of red junglefowl was split from their parent population (allopatric speciation) and gave rise, eventually, to Gallus gallus, then those red junglefowl adults became the first chickens, and thus, the chicken came first.
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bkelly Inactive Member |
From What Is a Chicken? - Incubation and Embryology - University of Illinois
Extension
quote: If a species cannot begat another species, and the only time genetic characteristics change is on the combination of sperm and egg, how did Gallus bankiva give rise to Gallus domesticus? If we were watching the transition one generation at a time, at what point would bankiva become domesticus? And why would we change our selection of its species name from bankiva to domesticus? Obviously we cannot speak in facts about what happened, but we can discuss the concept. Unless of course you know one heck of a lot more about the transformation of Gallus bankiva than I, which is rather probable.
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bkelly Inactive Member |
quote:quote: Are you certain about that? Look at all the different breeds of domesticated dogs and cats. They are so different that certainly they merit different species names. What about laboratory mice? There are hundreds of strains bred for specific uses. Each one is different because it has different genetic features that help with different experiments. It matters not that man induced the change, one species begat another. (I did have one person tell me that when change is caused by man, it is not evolution. It can only be evolution when it ocuurs in nature. I was amazed that an otherwise intelligent person would accept such nonsense.) Is there some place in the rules and guidelines about giving formal names to living things that excludes hybrid? I don't know much at all about orchids, but I do know that those who grow orchids mix and match to get new varieties and then provide these new varieties with new species names. I am concerned that I am becoming obnoxious about all this. I suppose that this thread should come to end soon, resolved or not.
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crashfrog Member (Idle past 1717 days) Posts: 19762 From: Silver Spring, MD Joined: |
If a species cannot begat another species When did I say that they couldn't? Of course species give rise to other species. Where else do the new species come from?
If we were watching the transition one generation at a time, at what point would bankiva become domesticus? It would be impossible to say, or at least, impossible for us to agree. That's rather my point. You might say it happened here, and I might say it happened three generations later there, and there would be no way to determine which of us was right.
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bkelly Inactive Member |
from message 103:
quote: Did I miss-uderstand this from messsage 96:
quote: But to be fair, I think my memory was a bit faulty as I was thinking of a post by John in which that was said.
quote: I agree. The naming of species is not and probably cannot be an exact science. After all, it is something imposed by humans. Nature does not catalog anything. But I do feel a tiny big ignored on one point. I keep saying that evolution in the sense for individuals occurs when the sperm and egg meaning the one cell unfertilized entity in the female) meet. Based on that, the egg (meaning the laid spheriod) deserved the name chicked before an adult did. Regardless, this thread has gone on long enough. Thanks for some good thoughts.
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NosyNed Member Posts: 9011 From: Canada Joined: |
The first half of your post, bk, is because the various posts aren't always exactly clear about separating species and individuals.
A species can give rise to another species but an individual always** gives birth to an individual of the same species as the parent. **always isn't exactly true but in this context it is close enough. So no red jungle fowl ever gives birth to a chicken but a red jungle fowl population eventually produced a chicken population. Have I helped at all?
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