|
Register | Sign In |
|
QuickSearch
Thread ▼ Details |
Member (Idle past 4982 days) Posts: 228 From: jo'burg, RSA Joined: |
|
Thread Info
|
|
|
Author | Topic: Can Domestic Selection cause Macroevolution? | |||||||||||||||||||||||
crashfrog Member (Idle past 1496 days) Posts: 19762 From: Silver Spring, MD Joined: |
How can parasitism not be symbiotic? I didn't say it wasn't, Kuresu. I mean I come right out and refer to parasitism as one kind of symbiosis. How can I be clearer than that?
I hope I don't have to point out the contradiction again. You haven't pointed it out the first time. Pointing out that symbiosis doesn't have to be parasitic isn't contradictory. I mean, c'mon, Kuresu. How dumb do you think I am? Why would I contradict myself in a single post?
Quote E is from the post I'm directly replying to. You say that you didn't say what you actually did say. In other words, you said you never said quote D, but you did. Where's the contradiction between D and E? Seriously, Kuresu, you're having reading problems of some kind. You keep quoting my exact words and then you keep failing to actually read them.
|
|||||||||||||||||||||||
crashfrog Member (Idle past 1496 days) Posts: 19762 From: Silver Spring, MD Joined: |
Crashfrog has explicitly said that parasitism is not symbiotic No, I haven't! It's like I'm in the Twilight Zone or something. How are all you people reading the exact opposite meaning of my words? Can anybody explain what's going on, here?
|
|||||||||||||||||||||||
Belfry Member (Idle past 5115 days) Posts: 177 From: Ocala, FL Joined: |
I agree, crash, you've used the terms both consistently and correctly throughout, as far as I can tell. This confusion is bizarre.
Since most of us, including kuresu, seem to agree that symbiosis includes many types of relationships, including both parasitism and mutualism, and may be obligate or facultative... perhaps we can move on at this point.
|
|||||||||||||||||||||||
kuresu Member (Idle past 2542 days) Posts: 2544 From: boulder, colorado Joined: |
look at my edit where I see that you were right on the mutualism. I was putting in a "not" after the does. My mistake there. As to the other, let me get back to that point later.
|
|||||||||||||||||||||||
crashfrog Member (Idle past 1496 days) Posts: 19762 From: Silver Spring, MD Joined: |
I don't see how discussion can continue between us.
|
|||||||||||||||||||||||
kuresu Member (Idle past 2542 days) Posts: 2544 From: boulder, colorado Joined: |
take at look at your post, number 64 in this topic. You say parasitism is not symbiotic, and then include it in you definition of symbiotic relationships.
You're right, a symbiotic relationship does not have to be parasitic because there are other forms of symbiosis. But you said that a parasitic relationship is not symbiotic in the first post, number 64 And if you all will take a look at the post that you quoted from of mine, I state that our relationship with corn is symbiotic because of what I called its parasititic nature, with the understanding that parasitism is A form of symbiosis. To use modulus' example, you are saying Car(symbiosis) is not Ford(parasitism) In effect, parastism is symbiotic, as is commensualism and mutualism And this is why I hate Aristotle
|
|||||||||||||||||||||||
crashfrog Member (Idle past 1496 days) Posts: 19762 From: Silver Spring, MD Joined: |
You say parasitism is not symbiotic I. Didn't. Say. That. It's really just that simple, K. If you can't read plain statements in English then discussion with you is not going to be possible.
|
|||||||||||||||||||||||
kuresu Member (Idle past 2542 days) Posts: 2544 From: boulder, colorado Joined: |
did you at least look at yuor old post? Because you do state that. All I was doing to begin with was pointing out what appeared to be a logical contradiction.
Please, do not make any more stabs at my reading ability. Especially considering that my reading level is above college level, and I'm but a high school senior taking an english class that requires extensive thought into all that literary stuff.
|
|||||||||||||||||||||||
crashfrog Member (Idle past 1496 days) Posts: 19762 From: Silver Spring, MD Joined: |
Because you do state that. No, I don't. Let me see if I can make it clearer. These two statements do not mean the same thing: "Symbiosis is not the same as parasitism." "Parasitism is not a kind of symbiosis." I repeat - these statements do not mean the same thing, so quoting my first statement to try to prove I said the second doesn't work. Is that clearer for you? Do you understand now that these two statements have two entirely different meanings?
Especially considering that my reading level is above college level, and I'm but a high school senior taking an english class that requires extensive thought into all that literary stuff. "Literary stuff", huh? Yeah I can't imagine what I was thinking, criticizing your reading prowess. Please accept my tenderest apologies, just as soon as you understand, once again, that those two statements have entirely different meanings. This message has been edited by crashfrog, 04-06-2006 10:50 PM
|
|||||||||||||||||||||||
kuresu Member (Idle past 2542 days) Posts: 2544 From: boulder, colorado Joined: |
here's the contradiction in a nutshell.
I state that our relationship with corn is not symbiotic unless you count it as a parasitic one. I never considered it to be mutualistic, but that term can take parasitic's place. This implies that the relationship is symbiotic because it is mutualistic (or parasitic). You state that symbiosis is not the same as parasitism. you then go on to define all symbiotic relatioships, which include these two. You then state that because our relationship with corn is mutualistic, it qualifies as a symbiotic relationship. Exactly what I said, but with parasitism. The whole point of that post (correct me if I'm wrong) is that my statement that the relationship is symbiotic if it is parasitic was wrong. Why else do you reply with "symbiosis is not the same as . . . ." But your statement at the end of that post is but a carbon copy of mine (with one term change). The implication then is that my statement was illogical and incorrect and that yours is logical and correct. But we said the same, d**m thing.
|
|||||||||||||||||||||||
Quetzal Member (Idle past 5901 days) Posts: 3228 Joined: |
Hi there, O Tusked Hairy Extinct One! I wish I could be around a lot more, but I have little time to do much more than lurk occasionally. How's the book going?
|
|||||||||||||||||||||||
U can call me Cookie Member (Idle past 4982 days) Posts: 228 From: jo'burg, RSA Joined: |
Hi Sasquatch,
I've argued before, so I might as well argue now, that dog breeds are a ring species. That is, certain breeds are reproductively isolated from one another (in a pre-mating sense), except for the fact that genetic flow could occur between them using other breeds. If all domestic dogs except for dachsunds and saint-bernards were wiped off the face of the planet, the remaining dachsunds and saint-bernards would represent two species because of pre-mating reproductive isolation. In absence of human intervention, I don't see the two breeds as being reproductively compatible. So... this doesn't mean "dog breed speciation" has happened as a result of artificial selection, but I think it shows artificial selection could produce such distinct creatures from a common ancestor as to be morphologically/behaviorally incompatible for reproduction. So i take it you're saying that while speciation has not yet occurred, the breeds are morphologically distinct enough to be regarded as on the pathway to speciation, due to physical incompatibility. I've mentioned before that i do accept this as a possibility, however, that incompatibility is not absolute. While it is rare, it is possible for a really small dog to mate with a really big dog; I've seen a case of it. What i'm saying though, is that certain factors of DS make it less conducive to speciation than NS. This however, i've realised, is dependent on the dynamics of specific DS situations.
Another example that comes to mind is mice that are selected for karyotype abnormalities by genetics laboratories. Mice bred to homozygosity for the novel, "abnormal" karyotype, even though happy, healthy, and fertile, are no longer interfertile with mice with the original "normal" karyotype. It is important to note that these karyotype-level mutational changes do occur naturally, (though they have also been induced). This is an example of artificial selection producing two populations of mice that are post-mating reproductively isolated (speciated) from one ancestor population.
This i hadn't heard of. Is this a by-product of the process, or are they specifically meant to be non-interfertile? "The good Christian should beware the mathematician and all those who make empty prophecies. The danger already exists that the mathematicians have made a covenant with the devil to darken the spirit and to confine man in the bonds of hell." - St. Augustine
|
|||||||||||||||||||||||
Mammuthus Member (Idle past 6504 days) Posts: 3085 From: Munich, Germany Joined: |
Hi Q,
I tried emailing you about it but could not get through. Will be shifting address soon..back to the US. Send my an email if you get a chance.
|
|||||||||||||||||||||||
Mammuthus Member (Idle past 6504 days) Posts: 3085 From: Munich, Germany Joined: |
Hi cookie,
You are absolutely right. But what I found striking is that even after a bottleneck, you still have a bell curve! It just shows that you really have to almost completely slaughter every living member of a species to knock down even morphological variation..and even if you do, it will quickly recover. From my own research interests, it makes me wonder how intense the pressure must be to drive a species to extinction since even if you bottleneck down to a single breeding pair, the population COULD recover and become diverse once again. What is neat with the corn example is that it recovered pretty quickly even after (you are right, effective pop size 20 not actual pop size) a pretty strong bottleneck. I only bring up these papers because all of this is stuff Faith claimed cannot occur i.e. bottleneck means terminal loss of all diversity. But all of these scenarios point to ways in which macroevolution can and does occur. Plants are particularly good at this due to hybridization and self pollination. Most of the references are out of my specialty i.e. I don't do plants or bugs I am sure I am missing more of the literature since I just did a cursory search in PubMed....anyone else out there have more or better references?
|
|||||||||||||||||||||||
U can call me Cookie Member (Idle past 4982 days) Posts: 228 From: jo'burg, RSA Joined: |
I think though, that the fact that you still have a bell curve is related to the trait examined (i think you mentioned something about this in your first post). Specifically, it was a quantitative trait that showed the bell curve. I don't expect that this is particularly surprising though, even after a bottleneck.
As an example, my immediate family works pretty well. My father is dark skinned, while my mother is fair skinned. My sisters and i all differ in complexion to both my parents, with one sister sort of olive-skinned, the other, kind of intermediate between my parents, and me being darker than my father. There's a bell curve right there - from the additive combinations of alleles of two individuals. The looked at the variance of non-additive traits as well, and found the reverse of the above, with the broad population showing drastically higher variance. This is not to say that diversity will not recover, but it will not do so quickly, unless re-introduced into the bottlenecked population. The maize example was interesting in that even though there was a strong bottleneck, the extremely high levels of diversity in the ancestral population, allowed enough variation to be carried over into Z. mays. It was not so much that it recovered quickly, but that there was substantial variation to begin with. I'm now more of the mindset that it is more likely isolation that does more to bring about macroevolution, than the actual selective process. Although, high diversity in the ancestral population would not hurt either. You're out of your specialty!? I explicitly opted out of most plant-based courses in undergrad...but i think that had a lot to do with my bias against gardening "The good Christian should beware the mathematician and all those who make empty prophecies. The danger already exists that the mathematicians have made a covenant with the devil to darken the spirit and to confine man in the bonds of hell." - St. Augustine
|
|
|
Do Nothing Button
Copyright 2001-2023 by EvC Forum, All Rights Reserved
Version 4.2
Innovative software from Qwixotic © 2024