Starting today August 7th, 2024, in order to post in the Married Couples, Courting Couples, or Singles forums, you will not be allowed to post if you have your Marital status designated as private. Announcements will be made in the respective forums as well but please note that if yours is currently listed as Private, you will need to submit a ticket in the Support Area to have yours changed.
what utterly rubbish, and I will demonstrate that by providing two counterexamples to your baseless allegation. There are a number of organisms that use both sexual and asexual reproduction throughout their own lifecycles, from aphids to volvox. Come on mark, if you are going to pretend to know what you are talking about, at least do a bit of reading ok?mark kennedy said:They do not survive when they have to compete with unmutated strains. The selective advantage for asexually reproducing organisms is twice that of sexually producing ones. Natural selection would eliminate these supposed transitions at the first sign of trouble and this is a demonstrated fact.
Jet Black said:what utterly rubbish, and I will demonstrate that by providing two counterexamples to your baseless allegation. There are a number of organisms that use both sexual and asexual reproduction throughout their own lifecycles, from aphids to volvox. Come on mark, if you are going to pretend to know what you are talking about, at least do a bit of reading ok?
h2whoa said:Mark are you suggesting that that abstract you posted refutes what Jet and myself have stated that there are organisms that breed sexually and asexually?
h2
perhaps you might try posting something remotely relevant. you made a claim that sexually reproducing organisms in one species cannot coexist and that the sexual reproducers would be driven extinct by sayingmark kennedy said:I have been reading, here is one of the articles I found particularly interesting:
"Identifying the forces responsible for the origin and maintenance of sexuality remains one of the greatest unsolved problems in biology. The mutational deterministic hypothesis postulates that sex is an adaptation that allows deleterious mutations to be purged from the genome; it requires synergistic interactions, which means that two mutations would be more harmful together than expected from their separate effects. We generated 225 genotypes of Escherichia coli carrying one, two or three successive mutations and measured their fitness relative to an unmutated competitor. The relationship between mutation number and average fitness is nearly log-linear. We also constructed 27 recombinant genotypes having pairs of mutations whose separate and combined effects on fitness were determined. Several pairs exhibit significant interactions for fitness, but they are antagonistic as often as they are synergistic. These results do not support the mutational deterministic hypothesis for the evolution of sex."
Entrez PubMed
You may have missed this paper being introduced to the thread while you were gone. Maybe you have something else I should be reading instead of scientific papers on the subject.
well it isn't a demonstrated fact, and I provided two living examples of the fact that you are dead wrong in that matter, because natural selection does not eliminate the sexually reproducing members in these cases. There are lots of other organisms that reproduce both sexually and asexually."Natural selection would eliminate these supposed transitions at the first sign of trouble and this is a demonstrated fact."
again nonsense. If you actually bothered to read up on organisms that reproduce both sexually and asexually you will find that there are selective advantages to each of the reproduction types, usually depending on the stresses on the organisms.mark kennedy said:No what I am saying is that the transition from asexual reproduction to sexual reproduction does not produce a selective advantage.
Jet Black said:perhaps you might try posting something remotely relevant. you made a claim that sexually reproducing organisms in one species cannot coexist and that the sexual reproducers would be driven extinct by saying
well it isn't a demonstrated fact, and I provided two living examples of the fact that you are dead wrong in that matter, because natural selection does not eliminate the sexually reproducing members in these cases. There are lots of other organisms that reproduce both sexually and asexually.
It wasn't even remotely relevant to my clear examples which contradict what you said.mark kennedy said:It is very relevant since this thread is a spinoff from the formal debate Aron-Ra and I had. Evolution as an explanation for our origins must begin with the transition of the single celled ancestor. For this to happen there has to be a transition from asexual to sexual reproduction that provides a selective advantage. Since mutations are given credit for driving evolution this is a prime example of how descent from a single common ancestor is presumption, not science. The signiture says it all.
oh those goalposts. how they move. so now you admit that your original thesis that asexual reproducers will outperform sexual reproducers is wrong, based on the existance of organisms that actually do both.So what if there are organisms that do that? Does this mean that we must presume that single celled organisms are our ancestors? Now for evolution to be an explanation for our origins then we must test the theory through hypothesis.
so the creationist "model" predicts that things shouldn't happen that do happen. that is called falsified. you can drop your "model" in the trash now, along with your meaningless definitions of "kind"In support of this the authors cited 6 scientific papers supporting it and none to the contrary. This is exactly what the creation model predicts, stasis is what Genesis describes as 'begat after kinds'.
Jet Black said:It wasn't even remotely relevant to my clear examples which contradict what you said.
oh those goalposts. how they move. so now you admit that your original thesis that asexual reproducers will outperform sexual reproducers is wrong, based on the existance of organisms that actually do both.
so the creationist "model" predicts that things shouldn't happen that do happen. that is called falsified. you can drop your "model" in the trash now, along with your meaningless definitions of "kind"
Did you miss this or just simply chose to ignore it. In order for living systems to have emerged from single celled organisms they must make this transition. There is no demonstrated mechanism for this in natural science just a naturalistic presumption that it must have occured. This has produced a mythology as to our origins to this day. There is no selective advantage produced by any of the hypothesis generated by this theory of single common ancestory. No other theory in natural science would be given this kind of tolerance and it is, as Bacon described it, an idol of the mind.
exactly, TO TEST ONE HYPOTHESIS ON THE ORIGIN AND MAINTENANCE OF SEXThat is the whole point of the experiments, to test a hypothesis as to the origin and maintance of sex. You say that I don't understand the paper and you make a statement like that...you are in denial and that is putting it mildly.
the yeast genome duplication, the shared ERVs, the rRNA phylogeny, the hox expansions, the phylogeny of pseudogenes, the presence of ciliary photoreceptor cells in Platynereis dumerilii etc etc etc....Such as?
mutation and natural selection mark - something you clearly don't understandOn the contrary, to say that it has a demonstrated mechanism is unmitigated mythology.
it simply means a new hypothesis must be formulated and tested, something real scientists do (and creationists don't do)Go back and look at figure 1 and read the discussion. Then go back to Aron-Ra's step 3 and rethink you're theory.
whats that got to do with anything? CLEARLY sex provides some advantage, or organisms wouldn't continue to reproduce that way when they are also able to reproduce asexuallyThey have both been around since the begining of life on earth, that is the point.
irrelevant to the point i'm making, which is that organisms reproduce sexually, despite your claim that it is disadvantageousSure, but how did they evolve from asexual single celled organisms, that's the real question here.
I know, it amazes me how befuddled you are tooMaybe to a 10 year old but a mature adult...
reproducing both sexually and asexually is clearly intermediate between either sexual or asexual reproduction aloneThere is no intermediate stage, that's a myth.
no IT ISN'T!No, I know what the paper demonstrated and it's the opposite of what the descent from a single cell ancestor model predicts.
there are no larger implications, other than a need to formulate a new hypothesis for the evolution of sexThe larger implications are both evident and obvious, in fact, they are explicitly stated in the paper.
I don't like people who can't understand the papers they think challenge "naturalistic assumptions"You don't like having you're naturalistic assumptions challenged do you?
is it?Then why is sexual and asexual reproduction part of the definition of kingdom in modern taxonomy?
YES, AND?Did you even read it because the conclusion was pretty clear.
"Even with this conservative approach, three synergistic and four antagonistic interactions are significant. Therefore, the mutational deterministic hypothesis seems to fail not because interactions between deleterious mutations are very rare, but rather because synergistic and antagonistic interactions are both common."
mark kennedy said:The combined effect in multiple mutations decrease fitness more then single ones. What you have in the first figure is an decreasing exponential curve, check it out for yourself, you have the paper, the evidence is right there.
OH GOD HELP ME, YOU STILL DO NOT UNDERSTAND THE PAPERNo what I am saying is that the transition from asexual reproduction to sexual reproduction does not produce a selective advantage. The interesting thing about the paper is that they demonstrate that both synergistic and antagonistic mutations were the result. The trouble was not that there were no beneficial mutations but that harmfull ones were just as common. There is no selective advantage to this transition and the reason for this is pretty obvious, it never happened.
my irony meter just imploded - clearly reading the paper hasn't helped you at all, because you're still making trivial mistakes about what the paper is aboutOh the clutch phrases, how they are so desperatly clung to. Asexual reproducers have twice the selective advantage and as the number of mutations are increased the selective advantage declines even more. I think you need to catch up on you're reading Jet, I suggest you start with this paper.
yossarian said:ITS NOT ABOUT MECHANISM, ITS ABOUT SELECTIVE ADVANTAGE
maybe if I shout, you'll finally get it
exactly, TO TEST ONE HYPOTHESIS ON THE ORIGIN AND MAINTENANCE OF SEX
ERGO, ALL ONE CAN SAY IS THAT THIS PARTICULAR HYPOTHESIS IS NOT SUPPORTED BY THE DATA
the yeast genome duplication, the shared ERVs, the rRNA phylogeny, the hox expansions, the phylogeny of pseudogenes, the presence of ciliary photoreceptor cells in Platynereis dumerilii etc etc etc....
each new edition of nature/science et al contains numerous examples of the utility of evolution
mutation and natural selection mark - something you clearly don't understand
it simply means a new hypothesis must be formulated and tested, something real scientists do (and creationists don't do)
whats that got to do with anything? CLEARLY sex provides some advantage, or organisms wouldn't continue to reproduce that way when they are also able to reproduce asexually
irrelevant to the point i'm making, which is that organisms reproduce sexually, despite your claim that it is disadvantageous
I know, it amazes me how befuddled you are too
reproducing both sexually and asexually is clearly intermediate between either sexual or asexual reproduction alone
no IT ISN'T!
its the opposite of what the synergistic epistasis model of the evolution of sex would predict, and nothing more
there are no larger implications, other than a need to formulate a new hypothesis for the evolution of sex
I don't like people who can't understand the papers they think challenge "naturalistic assumptions"
is it?
YES, AND?
thats exactly what i've been saying, and exactly what you've been contradicting for several posts now
yossarian said:OH GOD HELP ME, YOU STILL DO NOT UNDERSTAND THE PAPER
-the paper DOES NOT ADRESS BENEFICIAL MUTATIONS AT ALL
-the paper DOES NOT SAY "HARMFUL MUTATIONS ARE JUST AS COMMON"
-MUTATIONS CANNOT BE SYNERGISTIC OR ANTAGONISTIC, THESE TERMS REFER TO THE INTERACTIONS BETWEEN MUTATIONS, NOT THE MUTATIONS THEMSELVES
-IT DOES NOT SAY THAT SEX DOES NOT PROVIDE A SELECTIVE ADVANTAGE, IT SAYS THAT SYNERGISTIC EPISTASIS IS NOT A SELECTIVE ADVANTAGE THAT EXPLAINS SEX, BECAUSE ANTAGONISTIC EPISTASIS IS JUST AS COMMON
-THIS PAPER DOES NOT FALSIFY THE EVOLUTION OF SEX, IT FALSIFIES A PARTICULAR HYPOTHESIS THAT ATTEMPTS TO EXPLAIN WHY THE EVOLUTION OF SEX OCCURED
my irony meter just imploded - clearly reading the paper hasn't helped you at all, because you're still making trivial mistakes about what the paper is about
you are the one who needs to do some reading, of biology textbooks - maybe then you'll have the knowledge required to read and understand articles like this one
Identifying the forces responsible for the origin and maintenance of sexuality remains one of the greatest unsolved problems in biology. The mutational deterministic hypothesis postulates that sex is an adaptation that allows deleterious mutations to be purged from the genome; it requires synergistic interactions, which means that two mutations would be more harmful together than expected from their separate effects. We generated 225 genotypes of Escherichia coli carrying one, two or three successive mutations and measured their fitness relative to an unmutated competitor. The relationship between mutation number and average fitness is nearly log-linear. We also constructed 27 recombinant genotypes having pairs of mutations whose separate and combined effects on fitness were determined. Several pairs exhibit significant interactions for fitness, but they are antagonistic as often as they are synergistic. These results do not support the mutational deterministic hypothesis for the evolution of sex.
Among some 20 hypotheses, two postulate that sex is an adaptation for purging deleterious mutations from the genome.
And then, even if all those 18 others are falsified as well, the evolution of sex itself isnt even questioned in this article, so youll have to come with something else to falsify that. We might come up with a 21st hypothesis that does explain the force behind the evolution of sex. Or even if we dont, if we definitely prove all 20 current hypothesis false and havent got a 21st hypothesis, we can easily say that we dont know what the driving force is behind the evolution of sex, since these hypothesis do not test whether the evolution of sex occurs, but why the evolution of sex occurs.
there is no selective advantage provided by epistasisNatural selection is supposed to be the mechanism and there is no selective advantage and writing in caps won't change that fact.
we don't get a negative result everytimeA fanatic is someone who doubles their efforts when they have lost sight of their goals. The goal here is to test hypothesis that are the product of a theory. When you get a negative result every time you test a hypothesis from a particular theory then maybe the theory is wrong.
I can't decide whether your misunderstanding is willful or simply misguidedThis one hypothesis that asserts that mutations provide synergistic effects has been soundly disproven. Mutations do not drive evolution, they destroy it.
I just cited numerous examplesYou seem to forget I read these articles and you have yet to cite one example.
they change the genetic code and along with natural selection, shape genomesI just don't accept the myth of evolution, mutations do not write the genetic code.
there is a way for it to happen - mutation and natural selectionOk, I am going to assume you really don't understand. The single celled protorganism must make this transition and there is no way for it to happen. On the other hand, if the creatures are created fully formed then they will continue to begat according to kinds, just as single celled organisms will. Single celled organisms have no way of making the transitions the myth makers are telling you they did. Got it?
i'm making no assumptionsActually it is irrelevant due to the assumptions you are making.
my new irony meter isn't in yet, but i'll just point out that all your summaries of the paper and of the evolution of sex are strawmenHonestly, I have never been more clear or convinced and I have evolutionists to thank for it. You guys are great, I couldn't make a better strawman argument then the ones you guys come up with.
its not a presumption - its simple logicMy what big presumptions you have.
because it remains unexplainedThen why is this crucial transition the greatest mystery in biology?
a theory that neither produces hypotheses or tests them - no thanks, there wouldn't even be an article to argue aboutNo we need to reclaim the theory that produced evolution in the first place, creationism.
this ***-for-tat is ridiculousI don't like people who don't want to admit what science has proven beyond skepticism.
please demonstrate it thenPlease be serious. I am enjoying this but my sides are starting to hurt.
you've said a whole variety of things, about beneficial mutations (not even adressed in the article), synergistic and antagonistic mutations (inherently nonsensical), and things likeNo you have not. I said that the synergistic effects were offset by the antagonistic one and 1 + -1 = 0. You keep insisting that it equals evolution and the math just doesn't add up. That was fun, lets do it again...argue in circles some more.
The combined effect in multiple mutations decrease fitness more then single ones. What you have in the first figure is an decreasing exponential curve, check it out for yourself, you have the paper, the evidence is right there.
Another interesting point of interest was that the more mutations the more the selective advantage is reduced, mutations are not driving evolution they drive organisms closer to extinction.
NO, ITS BECAUSE THE PAPER IS SPECIFICALLY ADRESSING SYNERGISTIC INTERACTIONS BETWEEN KNOWN DELETERIOUS MUTATIONSThat's because most mutations are deletreous or harmfull. The effects on the other hand may be beneficial and I doubt seriously that you are really thinking this through.
then why did you say "harmfull ones were just as common"No it says that antagonistic effects are produced in equal numbers
Yes I know, so what?
mark kennedy said:he interesting thing about the paper is that they demonstrate that both synergistic and antagonistic mutations were the result.
close enough markYes and it says this crucial transition from asexual to sexual is a mystery since the selective advantage goes to maintaining asexual reproduction in single celled organisms.
seeing as the paper only adresses deleterious mutations this statement is almost tautologous, and at the same time - completely irrelevant to the role of mutation in evolution, because it specifically and only deals with deleterious mutationst proves that the as mutations increase fitness declines and if you read the paper you allready know this.
you're drawing ridiculous conclusions from a paper that does not even adress the kind of mutations required for the transition, but only adresses a particular model for the selective effects of sexYou sure picked the right word here, trivial, you're hair spliting does not change the fact that mutations cannot account for this transition. It doesn't happen in nature, we are not the result of random naturalistic processes. Our ancestors were created by God, fully formed, and begat the generations that followed according to kinds.
I doubt that markI do read my biology textbook on a regular basis and I understand the article just fine. Another hypothesis based on the single celled common ancestor model bites the dust. Mendel was right and Darwin was wrong, live with it.
No Mark, you can conclude that sexual behaviour probably has evolved without knowing which forces are involved. One of the arguments for this is the existence of creatures which are both sexual and asexual. You still have not answered that argument brought forward by Jet Black. The only thing you have done till know is give us an article which looks at one hypothesis of the forces involved in this process, assert that this hypothesis is falsified and then shout 'murder!'. This has nothing to do with presumption of the researchers, it has everything to do with your presumptions.mark kennedy said:That my friend is the power of presumption. Why this statement has received so little attention is as much a mystery to me as the evolution of single celled organisms from asexual reproduction to sexual reproduction is to the scientists who wrote this article.
"Identifying the forces responsible for the origin and maintenance of sexuality remains one of the greatest unsolved problems in biology."
To be honest the original posting of exerpts from this article was meant to illustrate how Aron-Ra's steps did not demonstrate that the theory evolutionists are working from could support the universal common ancestor model. I have seen nothing to contradict this affirmation, in fact, the main point I was making would seem to be irrefutable. Mutations are not driving organisms to evolve, they are making them extinct.
Newton had an experimentum crucis (crucial experiment) that made his series of hypothesis a theory. What we are seeing now is that the theory of single common ancestory dictates the hypothesis no matter what the actual evidence says.
I understand that the positive effects of these particular mutations are offset by the harmfull ones. You will find that this holds true no matter how many false demonstrations of science this bogus theory produces. If there is a way of demonstrating that we did indeed evolve from single cell organisms then natural science has yet to produce it. The empirical proof does not support this theory and it should be removed when it fails the burden of proof on such a macro scale. No other theory in natural science would be given this much toleration and unless evolution wants to be discarded along with the pagan myths of Babylon, the theory of descent from a single common ancestor should discarded.
Bottomline, produce a demonstrated mechanism or continue to gaze at this idol of the mind.
Tomk80 said:No Mark, you can conclude that sexual behaviour probably has evolved without knowing which forces are involved. One of the arguments for this is the existence of creatures which are both sexual and asexual. You still have not answered that argument brought forward by Jet Black. The only thing you have done till know is give us an article which looks at one hypothesis of the forces involved in this process, assert that this hypothesis is falsified and then shout 'murder!'. This has nothing to do with presumption of the researchers, it has everything to do with your presumptions.
Even better, the hypothesis can be seen totally independent of the evolution of sexuality. It can be simply seen as answering the question 'sexual organisms should logically have less survival chances than asexual organisms, why are they so succesfull anyway?'. The hypothesis in fact answers this question. We just want to know why sexuality offers a benefit, since it is would be a logical conclusion that it doesn't. Whether evolution, creationism or 'last thursdayism' is the model used, the question remains the same.
yossarian said:there is no selective advantage provided by epistasis
your summaries are lazy and misleading
we don't get a negative result everytime
the vast majority are positive results
I can't decide whether your misunderstanding is willful or simply misguided
soundly disproven is a gross misstatement based on a single study of a small number of mutations in a single organism
mutations do drive evolution, the evidence is abundant in every article you ignored to dwell on this one particular article you keep misrepresenting
I just cited numerous examples
whether you've read the articles seems immaterial, whether you've understood any of them is the major issue
they change the genetic code and along with natural selection, shape genomes
there is a way for it to happen - mutation and natural selection
none of the rest of this adresses the fact that organisms that have both sexual and asexual reproduction actually do both in different circumstances - blowing your argument out of the water
i'm making no assumptions
organisms that reproduce both sexually and asexually exist - clearly a transition to sexual reproduction IS NOT impossible, else these organisms would never sexually reproduce
my new irony meter isn't in yet, but i'll just point out that all your summaries of the paper and of the evolution of sex are strawmen
its not a presumption - its simple logic
because it remains unexplained
a theory that neither produces hypotheses or tests them - no thanks, there wouldn't even be an article to argue about
this ***-for-tat is ridiculous
you plainly haven't understood the paper, despite numerous attempts to explain it to you - so any claims about what science has proven are undermined by your inability to understand what science is actually saying
you've said a whole variety of things, about beneficial mutations (not even adressed in the article), synergistic and antagonistic mutations (inherently nonsensical), and things like
NO, ITS BECAUSE THE PAPER IS SPECIFICALLY ADRESSING SYNERGISTIC INTERACTIONS BETWEEN KNOWN DELETERIOUS MUTATIONS
I have Bachelors of science majoring in genetics - being lectured on mutations is amusing and infuriating
then why did you say "harmfull ones were just as common"
seeing as the paper only adresses deleterious mutations this statement is almost tautologous, and at the same time - completely irrelevant to the role of mutation in evolution, because it specifically and only deals with deleterious mutations
its also a misleading way of summarizing the paper, because one of its conclusions is that the combined effect of some deleterious mutations is LESS DELETERIOUS than would be expected by a simple addition of their fitness costs
you're drawing ridiculous conclusions from a paper that does not even adress the kind of mutations required for the transition, but only adresses a particular model for the selective effects of sex
I doubt that mark
there are numerous violations of mendel's laws, something you'd know if you'd actually read any relevant textbooks
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?
We use cookies and similar technologies for the following purposes:
Do you accept cookies and these technologies?