Reversed Backcrossing:)

[englishrick]

The Main Reason For Using Fem`s

"sexual dimorphism, which can evolve quickly, can eliminate the frequency-dependent disruptive selection"

 

[englishrick]

SEXUAL DIMORPHISM AND ADAPTIVE SPECIATION: TWO SIDES OF THE SAME ECOLOGICAL COIN....by Daniel I. Bolnick and Michael Doebeli

the abstract is the best bit

 

[englishrick]

The Eole of Epistatic Gene Interactions In The Response To Selection And The Evolution Of Evolvability

Authors: Ashley J R Carter, Joachim Hermisson, Thomas F Hansen


It has been argued that the architecture of the genotype-phenotype map determines evolvability, but few studies have attempted to quantify these effects. In this article we use the multilinear epistatic model to study the effects of different forms of epistasis on the response to directional selection. We derive an analytical prediction for the change in the additive genetic variance, and use individual-based simulations to understand the dynamics of evolvability and the evolution of genetic architecture. This shows that the major determinant for the evolution of the additive variance, and thus the evolvability, is directional epistasis. Positive directional epistasis leads to an acceleration of evolvability, while negative directional epistasis leads to canalization. In contrast, pure non-directional epistasis has little effect on the response to selection. One consequence of this is that the classical epistatic variance components, which do not distinguish directional and non-directional effects, are useless as predictors of evolutionary dynamics. The build-up of linkage disequilibrium also has negligible effects. We argue that directional epistasis is likely to have major effects on evolutionary dynamics and should be the focus of empirical studies of epistasis.

 

[englishrick]

Evolution of genetic architecture under directional selection


Authors: Thomas F Hansen, José M Alvarez-Castro, Ashley J R Carter, Joachim Hermisson, Günter P Wagner



We investigate the multilinear epistatic model under mutation-limited directional selection. We confirm previous results that only directional epistasis, in which genes on average reinforce or diminish each other's effects, contribute to the initial evolution of mutational effects. Thus, either canalization or decanalization can occur under directional selection, depending on whether positive or negative epistasis is prevalent. We then focus on the evolution of the epistatic coefficients themselves. In the absence of higher-order epistasis, positive pairwise epistasis will tend to weaken relative to additive effects, while negative pairwise epistasis will tend to become strengthened. Positive third-order epistasis will counteract these effects, while negative third-order epistasis will reinforce them. More generally, gene interactions of all orders have an inherent tendency for negative changes under directional selection, which can only be modified by higher-order directional epistasis. We identify three types of nonadditive quasi-equilibrium architectures that, although not strictly stable, can be maintained for an extended time: (1) nondirectional epistatic architectures; (2) canalized architectures with strong epistasis; and (3) near-additive architectures in which additive effects keep increasing relative to epistasis.

 

[englishrick]

The Genetic Basis of Phenotypic Adaptation I: Fixation of Beneficial Mutations in the Moving Optimum Model


Authors: Michael Kopp, Joachim Hermisson


We study the genetic basis of adaptation in a moving optimum model, in which the optimal value for a quantitative trait increases over time at a constant rate. We first analyze a one-locus two-allele model with recurrent mutation, for which we derive accurate analytical approximations for (i) the time at which a previously deleterious allele becomes beneficial, (ii) the waiting time for a successful new mutation, and (iii) the time the mutant allele needs to reach fixation. Based on these results, we show that the shortest total time to fixation is for alleles with intermediate phenotypic effect. We derive an approximation for this "optimal" effect, and we show that it depends in a simple way on a composite parameter, which integrates the ecological parameters and the genetic architecture of the trait. In a second step, we use stochastic computer simulations of a multilocus model to study the order in which mutant alleles with different effects go to fixation. In agreement with the one-locus results, alleles with intermediate effect tend to become fixed earlier than those with either small or large effects. However, the effect size of the fastest mutations differs from the one predicted in the one-locus model. We show how these differences can be explained by two specific effects of multilocus genetics. Finally, we discuss our results in the light of three relevant time scales acting in the system - the environmental, mutation, and fixation time scale - which define three parameter regimes leading to qualitative differences in the adaptive substitution pattern.

 

[englishrick]

Epistasis in polygenic traits and the evolution of genetic architecture under stabilizing selection


Authors: Joachim Hermisson, Thomas F Hansen, Günter P Wagner


We consider the effects of epistasis in a polygenic trait in the balance of mutation and stabilizing selection. The main issues are the genetic variation maintained in equilibrium and the evolution of the mutational effect distribution. The model assumes symmetric mutation and a continuum of alleles at all loci. Epistasis is modeled proportional to pairwise products of the single-locus effects. A general analytical formalism is developed. Assuming linkage equilibrium, we derive results for the equilibrium mutation load and the genetic and mutational variance in the house of cards and the Gaussian approximation. The additive genetic variation maintained in mutation-selection balance is reduced by any pattern of the epistatic interactions. The mutational variance, in contrast, is often increased. Large differences in mutational effects among loci emerge, and a negative correlation among (standard mean) locus mutation effects and mutation rates is predicted. Contrary to the common view since Waddington, we find that stabilizing selection in general does not lead to canalization of the trait. We propose that canalization as a target of selection instead occurs at the genic level. Here, primarily genes with a high mutation rate are buffered, often at the cost of decanalization of other genes. An intuitive interpretation of this view is given in the discussion.

 

[BENJI]

This is the last post in this thread until i have tried STS and have some EVIDENCE until then good luck cause your gonna need it..

Dont get me wrong bro i aint hear to stamp on your theory i just want to see it happen and so do alot of other people i will continue to read the thread and i am still going to use STS on my jack herer clone..

Most of your posts are informative but when a thread gets 30 pages long and only 4-5 pages are worth reading it gets a bit much sorting the stuff that doesnt belong in this thread i think it would be much easier to comprehend and easier for other people aswell if it was kept on point i think chimera summed it up perfectly..

I'd like to respond to this thread, but:

A) reading it hurts my brain... likely because...

B) there is so much nonsense on these pages that I don't even know here to begin.


It's not that I don't like you Rick, I don't know you... but I do think you post alot of nonsense about topics you don't understand, which leads to more confusion as people read your words and might not realize that you really don't understand what you are talking about.

I've been trying to clarify many of these cannabis breeding topics on the internet for over 10 years.... and really these threads make me feel like all that work, all those explanations was for naught!

Have you read any breeding texts? Marijuana Botany? Allard's Principles of Plant
Breeding?

I wrote a small, simple chapter for Jorge Cervantes' Medical Bible that I think might clarify some of your basic assumptions re: breeding cannabis. I would recommend you search that out, read it a couple of times and then get back on your path to enlightenment. Maybe armed with the basics you could then approach Allard's work, or many other excellent writtend works on plant breeding.

Good luck in your search,
-Chimera

U might be gifted bro but copying and pasting stuff you read just go's to prove Chimeras response and no offence but if your questioning Chimera then i hafto question you..You should listen to people that have experience and take what they say very very seriously, remember your the one that called Chimera out...

 

[englishrick]

This is the last post in this thread until i have tried STS and have some EVIDENCE until then good luck cause your gonna need it..

Dont get me wrong bro i aint hear to stamp on your theory i just want to see it happen and so do alot of other people i will continue to read the thread and i am still going to use STS on my jack herer clone..

Most of your posts are informative but when a thread gets 30 pages long and only 4-5 pages are worth reading it gets a bit much sorting the stuff that doesnt belong in this thread i think it would be much easier to comprehend and easier for other people aswell if it was kept on point i think chimera summed it up perfectly..



U might be gifted bro but copying and pasting stuff you read just go's to prove Chimeras response and no offence but if your questioning Chimera then i hafto question you..You should listen to people that have experience and take what they say very very seriously, remember your the one that called Chimera out...

benj bro.....when i say gifted,,,i mean special,,,,,,special needs,,,,yes i am disabled

im thankfull Chimera took the time to read this,,,,,i keep offering new info,,,,so i constantly need telling im wrong,,,an thats fine by me

the words "calling him out" makes me sound like a cowboy.....its not 10 to 10 bro

 

[VerdantGreen]

a couple of points.

firstly, i have to say that whilst i have huge respect for Chimera, and im not trying to 'call him out' (not even sure what it means)

but if it is so important to him that we avoid this avenue of breeding - using selfing or fems - then why couldnt he either give us an outline of why it is so bad or at least provide some links to where we could read more about it. Links to the internet are much more accessible than books for most people.
after all this thread has had 7000 hits! he could reach a lot of people.
if some of us can't understand the complexities of the subject then that is all the more incentive for us to go out and do more research.

i have the cervantes book he reference and it is a great chapter he wrote - but only really touches on the subjects mentioned here. The marijuana botany book i have read some of but dont own - it's fairly obscure.

secondly, as a community or individuals we are unlikely to just listen to the 'voice of authority' and accept it blindly without questioning - if we were predisposed to do that then it is unlikely we would have tried cannabis in the first place, because most of the propaganda in society is advising against it.
we are the people that are hard-wired to question and experiment!

"Since the dawn of our species man's been blessed with curiosity" Tom Friendly


V.

 

[englishrick]

a couple of points.

firstly, i have to say that whilst i have huge respect for Chimera, and im not trying to 'call him out' (not even sure what it means)

but if it is so important to him that we avoid this avenue of breeding - using selfing or fems - then why couldnt he either give us an outline of why it is so bad or at least provide some links to where we could read more about it. Links to the internet are much more accessible than books for most people.
after all this thread has had 7000 hits! he could reach a lot of people.
if some of us can't understand the complexities of the subject then that is all the more incentive for us to go out and do more research.

i have the cervantes book he reference and it is a great chapter he wrote - but only really touches on the subjects mentioned here. The marijuana botany book i have read some of but dont own - it's fairly obscure.

secondly, as a community or individuals we are unlikely to just listen to the 'voice of authority' and accept it blindly without questioning - if we were predisposed to do that then it is unlikely we would have tried cannabis in the first place, because most of the propaganda in society is advising against it.
we are the people that are hard-wired to question and experiment!

"Since the dawn of our species man's been blessed with curiosity" Tom Friendly


V.

Wow Wow Wow Wow Wow Wow Wow wow Wow Wow Wow

i have the up most respect for you

i think the kids who stuck with this thread "including myself" are the 1s who deserve to be taught

i feel if i keep going ,,,im might even explain it myself

im desperate to know whats the BIG DEAL about selfing?.......i want to know,,,,i need help,,,im going crazy,,,,i read the abstract bits of science papers promoting the positivitys of SELFING,,,,,yet everyone who grows weed becomes negative with me,,,,,exept for Colina of corse...love you col....

col is the only guy

 

[englishrick]

ive not even heard the word Agamospermsyet....

whats going on!!

bla bla bla pages ,,,and no talk of Agamosperms,,,gime a brake

 

[englishrick]

hay V green......read this see what you think,,,,,its an easy 1,,,

even i read it.......check out the bit called "THE COST OF SEX"

Reproductive systems and evolution in vascular plants by Kent E. Holsinger

http://ukpmc.ac.uk/articlerender.cgi?artid=274753

 

[englishrick]

The direct genetic consequences of self-fertilization and asexual reproduction are quite different. Self-fertilization causes progeny to be heterozygous at only half as many loci, on average, as their parents, and highly selfing populations are composed primarily of homozyous genotypes. Asexual reproduction, however, results in progeny that are genetically identical to their parents, barring somatic mutation, and asexual populations therefore may be highly heterozygous. Because self-fertilization and asexual reproduction both prevent exchange of genetic material among family lineages, however, the number of genotypes found in populations of predominant selfers or obligate asexuals is usually much smaller than would be found in a population of sexual outcrossers with the same allele frequencies. For similar reasons, surveys have repeatedly shown that a greater proportion of the genetic diversity found in selfing or asexual species is a result of differences among populations than in sexual outcrossers (24–26, 69). In short, the great diversity of reproductive systems exhibited by vascular plants is matched by a similar diversity of genetic structures within and among their populations. Indeed, the diversity of reproductive systems may be the predominant cause of the diversity in genetic structure.
Differences in genetic structure associated with differences in reproductive systems were once commonly invoked as evolutionary forces governing their origin (3, 70, 71). Although such differences may help us to understand why some lineages persist and diversify and others do not, we now realize that to understand the origin of alternative reproductive systems we must look for benefits and costs associated with individual survival and reproduction. Moreover, the comparison of self-fertilization and agamospermy shows that the most important distinction for hermaphroditic organisms is between uniparental and biparental forms of reproduction. Uniparental reproduction, whether through selfing, agamospermy, or apogamy, excludes sexual outcrossers from contributing to some offspring that will form the next generation. If selfers, agamosperms, or apogams are able to contribute to some sexual offspring, genotypes promoting that mode of reproduction will be over-represented in the next generation, reflecting the cost of outcrossing.
To the segregational cost of outcrossing can be added another: selfers, agamosperms, and apogams are able to produce offspring even under conditions that prevent the union of gametes produced by different individuals. The benefit of this reproductive assurance seems so apparent that it is surprising how few experimental studies have been done to document it and how equivocal their results are (50). When plants reproducing uniparentally benefit from reproductive assurance or are over-represented in the next generation as a result of donating gametes to the outcrossed progeny of other individuals, they eventually will replace sexual outcrossers in the population, unless the progeny of sexual outcrossers are substantially more likely to survive and reproduce. Thus, the relative fitness of different types of individuals competing in a population and the frequency with which different types are formed will determine whether outcrossers persist in the short term or are replaced by selfers or asexuals.
In the long term, however, differences in the ability of outcrossers, selfers, and asexuals to respond to environmental change and resist the accumulation of deleterious alleles may cause lineages with different reproductive systems to persist for different lengths of time. The smaller number of genotypes in highly selfing and asexual populations may reduce the efficiency with which natural selection can operate, limiting the ability of their populations to respond adaptively to a changing environment—the uniparental constraint. In addition, highly selfing populations have an effective size only about half that of an outcrosser with the same number of individuals (44), and their size also tends to be more variable (23). Both selfers and asexuals, therefore, are more likely to accumulate deleterious mutations than sexual outcrossers, and these mutations could decrease their reproductive capacity and contribute to their early extinction through a mutational meltdown (45, 46).
In this sense, therefore, Stebbins (3), Grant (70), and Baker (71) were right to contend that selfers and asexuals lack the long-term flexibility characteristic of sexual outcrossers. Indeed, this lack of flexibility may explain why selfers and asexuals originate frequently from outcrossing ancestors, but often seem to be evolutionarily short-lived. If we are to have a comprehensive understanding of broad-scale evolutionary patterns in plants, therefore, we must begin to investigate the relationships among reproductive systems, rates of speciation, and rates of extinction, and we must begin to understand the causes of the relationships we find.

 

[englishrick]

how mutch do we know ...eh?

 

[Donald Mallard]

Wow Wow Wow Wow Wow Wow Wow wow Wow Wow Wow

i have the up most respect for you

i think the kids who stuck with this thread "including myself" are the 1s who deserve to be taught

i feel if i keep going ,,,im might even explain it myself

im desperate to know whats the BIG DEAL about selfing?.......i want to know,,,,i need help,,,im going crazy,,,,i read the abstract bits of science papers promoting the positivitys of SELFING,,,,,yet everyone who grows weed becomes negative with me,,,,,exept for Colina of corse...love you col....

col is the only guy

phew this thread keeps popping up everytime i look at the new posts.
on the keeping going rick ,, id stop if i were you , your gonna go blind man , really have to re-iterate what a few have said , for goodness sakes stop talking and go try your ideas.
the longer you sit here typing answers to yourself the more time you waste that you could be selfing yourself .. hehe ...

 

[BENJI]

all this input is grate......

hay Chimera,,,,you got me hangin,,,,i cant wait for your reply

please keep talking ,,,,il write a relpy later....nice one guys

i was plannin on isolating 1 trait from the mother into an "S" seedline,,,then using the origonal clones reverced polen to make a weird type of Fem F1

am i wrong col?


you got me itchim for Chimeras reply now

hay col

do you think chimera is gona come back an blow this outa the water??

grate...

hay chimera....bring it on!,,,,,,

i cant wait!

so whos is more harcore Charles Xavier , Suzy Creamcheese ,,,,or Chimera,,,im waiting for Chimeras reply,,,im waiting for a thrashing ,,,maybe

are you sujesting chimera is not coming back because "he dont like me"....

thats hurtfull,,,,not cool

I agree, with one basic change.

Preservation first, selection second THEN selfing selected individuals for genotyping purposes. Then, as Colina essentially said, once you know where you stand you are in a better position to decide where you want to go, and what path to follow.

-Chimera

all right,,,im gona keep my mouth shut more often,,,il work in quietly,,,,,,i hade grate fun on this thread,,,i hope other people did too,,,,an im sure it got people thinkin

i dont know enough yet to say anything "yet".....so lets leave it at that,,,,,,its my head and my problem,,,,sorry guys,,,i didnt think its was all nonsense.....thanks for reading

Chimera,,,am i still an idiot?

By Calling him out to reply to this thread i mean asking him for advice which u done on several occassions then you implied he was calling you an idiot not cool and colina has stated already he doesnt like the idea of reverse backcrossing maybe u should listen to them maybe u shouldnt its your descision in the end im happy for you either way...

And VerdantGreen I never said u were calling him out..

 

[Paco]

this thread is a waste of bandwidth. nothing good has come of it yet, and nothing good will ever come of it. it just wont die...

 

[VerdantGreen]

Wow Wow Wow Wow Wow Wow Wow wow Wow Wow Wow

i have the up most respect for you

i think the kids who stuck with this thread "including myself" are the 1s who deserve to be taught

i feel if i keep going ,,,im might even explain it myself

im desperate to know whats the BIG DEAL about selfing?.......i want to know,,,,i need help,,,im going crazy,,,,i read the abstract bits of science papers promoting the positivitys of SELFING,,,,,yet everyone who grows weed becomes negative with me,,,,,exept for Colina of corse...love you col....

col is the only guy

hi rick, im no expert, selfing or self pollination is a respected and useful horticultural technique but i think the difference with cannabis is that it has separate male and female plants which is quite unusual in the plant world. the vast majority of plants have both male and female parts on the same plant so self pollination is more of a natural process (although many of these plants have mechanisms to avoid pollen from one plant fertilising the female parts from the same plant. lovers of the weed are worried that the dreaded herms will be more common if selfing and that is understandable.
having said that then DJ short used hermi thai sativa in Bb - he said i think that it takes only a few generations of zero tolerence to eliminate herm traits but then there are still many reports of herms in Bb today. who knows?

i have an interest in the rights and wrongs of this because the best plant i have happens to be from fem seed and i am doing a lot of soul searching and research to help me decide if i should use it for breeding. im not trying to go against the flow just for the sake of it and neither are you.

i would listen to yourt mates here rick - actions speak louder than words - you have captured quite a few imaginations here and i think everyone is curious as to how your plans will play out in reality, but i think that people will eventually get bored of waiting for you to actually do it.

what is it that you are waiting for now? do you still need some chemicals/equipment or are you good to go?

 

[cork144]

aha good to see your still here on the subject rick

if you find some nice girls in your s1's and your bluesxcheese, why not cross the 2 lines over?

 

[McSnappler]

i have an interest in the rights and wrongs of this because the best plant i have happens to be from fem seed and i am doing a lot of soul searching and research to help me decide if i should use it for breeding.

I'm assuming the conclusion you're coming to is that if your best girl is from fem seed, you should stress test the arse out of her. If she doesn't herm under extreme growing stress, she's a true female, and can be used for breeding - regardless of whether she originates from feminised seed.