IN THE BEGINING THERE WAS MAN?

[dmaiski]

in the beginning there was RNA that self replicated

it made bacteria

bacteria was asexual

AND IT WAS GOOD

then came about a mutation!!

it made sexual bacteria

which raped everything

AND IT WAS GOOD

the there was a mutation!!

and the precursor for the SRY region was made

and it raped everything

and it was not so good

because as it raped everything

it passed on the SRY precursor

making MALE's

which could not reproduce

and only dragged down resources

you would think they would die out wouldn’t you

but no the persistent bastards raped everything even more

and became the dominant form of reproduction

 

and that is the history of mankind (well it is sort of)

 

 

and yes it is written in the bible... the first human was a woman, she stole the clay of creation, made man to be her buddy,

then god told her to obey man... (reminiscent of Frankenstein)

she told him no (in not so many words i think)

and went off to screw an angel

 

 

(of course this is dumbed down a lot and simplified, and i did take some poetic licence on it)

 

[jp255]

As I said in the other thread you posted this opinion. Sexual reproduction is the dominant form of reproduction, asexual species are in the minority. This suggests that sexual reproduction has been positively selected. So, you need to show that asexual reproduction is more positively selected than sexual reproduction in order to say sexual reproduction is not good.

 

 

You know that there are differences between asexual reproduction and sexual reproduction other than the proportion of the individual's genes passed on to each of his/her offspring?

 

Your quote thing under all your posts. "Be open to all ideas no mater how absurd, but also accept that most ideas are probably wrong.". Personally, I adopt this line of thinking "Be critical of all ideas no matter how logical they might appear to be, and assess how likely you think it to be true"

Edited September 6, 2012 by jp255

[dmaiski]

then came about a mutation!!

it made sexual bacteria

which raped everything

AND IT WAS GOOD

 

im not saying sexual reproduction is bad

in fact im sure i said it was good...

 

im saying having a male in the species is bad since it

1. draws resources that could otherwise be used

2. accumulates bad mutations (the Y chromosome is small for a reason and is bordering on becoming too small to function)

3. just isn’t an efficient method of reproduction

 

not that im suggesting we get rid of men... i do like being alive after all

 

 

Edited September 6, 2012 by dmaiski

[jp255]

and there are no positives to having a male sex? you are only listing the downfalls. why? Sure there are bad aspects to having a male sex. Overall though, would you not agree that a species with two sexes is more advantageous for animals?

[dmaiski]

and there are no positives to having a male sex? you are only listing the downfalls. why? Sure there are bad aspects to having a male sex. Overall though, would you not agree that a species with two sexes is more advantageous for animals?

 

please list them, i really don’t see any

(well there are some but those have examples of similar systems in asexual species that are more efficient)

 

reproductive control: asexual species show the same ability but at a biochemical level

portion of the workforce not burdened with carrying children: valid but rendered meninges by reproductive control

specialisation: a side effect of the system that will occur anyway even in asexual species (and the whole species will benefit from it)

 

 

so really there are no real advantages to having a male

 

the advantages of being a male are numerous tho (its the reason they are so popular)

 

no need to worry about offspring (rape, run off, rinse, repeat)

specialisation (the most advanced fire and forget missiles in existence: sperm!)

portion of the workforce not burdened with carrying children (its one of those ONLY IN HUMANS THINGS...)

less need for food, lighter, smaller (well your not going to be making anything are you)

 

 

ive listed the advantages

 

 

 

[jp255]

Your posts suggested that you do not know of the advantages to sexual reproduction. You shouldn't assume there are no advantages however, that's why I was griefing you a little . I will list them, but I don't have the time to go into them right now. Tomorrow.

 

"Be critical of all ideas no matter how logical they might appear to be, and assess how likely you think it to be true". This is a great example of how you can benefit from this line of thinking as opposed to yours. If one was to be critical of your approach, you'd say "Do you at least realise that it is highly likely that sexual reproduction is positively selected for to a greater extent than asexual reproduction because the proportion of all extant species that display either type of reproduction are massively different? (with sexual much higher)). So, you should expect there to be some missing advantages you don't have knowledge of to account for this.

Edited September 6, 2012 by jp255

[dmaiski]

it prevents thinning of the gene pool by allowing the mixing of various strains, and species of organism to produce new ones more, or less, adapted to the environment. it also allows a dieting species to occasionally cross-breed with a more successful species and live on in some form increasing the diversity of a genome and how successful the organisms will be.

 

another thing is it allows a single successful individual that is long lived to transfer its genes onto less successful individual thus expanding the number of successful individual

 

that basically the gist of why sexual reproduction is so successful (in genderless sexual species (bacteria, fungus, plants, archea)

a few of those points get really screwed up once you get a set sex (prokaryotes, well most of them) since you lose alot of the benefits while getting many disadvantages

the reason it has survived is that it allows multicellular organisms (prokaryotes, well most of them) to be produced for a reason i do not know

we are simply too large to compete with bacteria, fungus, and archea. and plants are our food source, while to plants we are nothing more then the occasional parasite and a method to spread their seeds over a larger area.

 

plants were at .8 on the kardashev scale and the dominant genus on the planet (by biomass) before we were even crawling out of the oceans so they have my respect

 

(plant have it all worked out; they are large multicellular complex organisms, produce they're own food, are naturally bi sexual hermaphrodites, and don't need to even move since they have swarms of symbiotic organisms that will do everything they ever need for them so they can focus all they're energy on growing bigger)

 

 

honestly the reason i post in forums is that i cant be perfectly critical of my own ideas, ill never get anything done, so i need other people to criticize them. If they cant stand up to it they're obviously not good ideas.

 

edit:

i got sidetracked talking about plants

as you can see im a fan of theirs from a genetics, and evolutionary point of view

Edited September 6, 2012 by dmaiski

[swansont]

and yes it is written in the bible... the first human was a woman, she stole the clay of creation, made man to be her buddy,

then god told her to obey man... (reminiscent of Frankenstein)

she told him no (in not so many words i think)

and went off to screw an angel [/size][/font]

!

Moderator Note

Seeing as this is posted in Biology, discussion of either the Bible or Shelley would seem to be off-topic.

[dmaiski]

!

Moderator Note

Seeing as this is posted in Biology, discussion of either the Bible or Shelley would seem to be off-topic.

 

i know really bad habit of mine, but its relevant somewhat, after all if there is a god he/she/it/[yet to be invented pronoun/all of the above] is a damn good biologist

 

back to being really on topic, or trying to be at least

(should i delet it?)

[swansont]

i know really bad habit of mine, but its relevant somewhat, after all if there is a god he/she/it/[yet to be invented pronoun/all of the above] is a damn good biologist

 

back to being really on topic, or trying to be at least

(should i delet it?)

!

Moderator Note

As long as everyone understands that the discussion does not follow that path, things are fine.

[Ophiolite]

Sexual reproduction is the dominant form of reproduction, asexual species are in the minority.

Really? Have you let the bacteria know?

[jp255]

The benefits of sexual reproduction over asexual reproduction are plentiful, and the ones you missed are the most important. I am strictly comparing organisms which exclusively reproduce asexually to those which exclusively reproduce sexually. There are numerous organisms which carry out both types of reproduction.

 

The biggest advantages of sexual reproduction are meiotic recombination and the contribution of alleles from two individuals, 50% of the individuals genetic material is not passed on to any one of it's offspring (ignoring mtDNA), selection of a mate.

 

Meiotic recombination and loss of genetic material are linked. Many advantages of meiotic recombination are lost if all information is passed on, there is no point in shuffling the allele order of a chromosome if everything is passed on. Consider the example below:

 

Two populations of 2000 individuals, pop A is asexual and pop B is sexual. pop A and B are the same organism and have same genome, just hypothetically considering the differring reproductive methods. In each pop, three individuals have positively selected for alleles allele x, y and z, which are not the alleles of the same gene and are single point mutations.

 

In pop B the three individuals carrying x y and z are more likely to survive and pass on their genes, but, there is also the chance that x, y and z might land on the same chromosome or in the same individual by either meiotic recombination or contribution of genes from two individuals (the three individuals reproduce with each other or offspring reproduce with each other). Individuals possessing x y and z will increase in probability with each successive generation as natural selection acts and x y and z are overrepresented, This probability is higher than asexual (and possibly rises in a non-linear manner, even after accounting for inheritance patterns).

 

In pop A the three individuals carrying x, y and z are more likely to survive and pass on their genes. There is a minute chance that x y and z land on the same chromosome or in the same individual, the probability that this happens is the chance that the single base in gene x y and z mutates to the correct base that makes allele x y and z (this can only initially occur in the three individuals. very low probability. increases in probability over generations at a linear (I think) rate).

 

So pop A does not have the capability to transfer the positively selected alleles present in the current population into one individual, it relies on all beneficial mutations occuring independently in one genome (sometimes the mutation might have occured before in other individuals, but it has to occur again to see both mutations in on individual so there is redundancy), so evolution occurs in a step-by-step manner (one good mutation after another, possibly two or more good mutations in one generation but unlikely). In contrast, Pop B has the capability to transfer the good alleles present in the population to one individual/chromosome and the liklihood that this will happen will increase over the generations at a greater rate than pop A(as the allele frequencies rise, the liklihood they will converge into one chromosome/individual increases). This also leads to reduced variability amongst pop A in comparison to pop B. Sexual reproduction has the potential to accumulate more positively selected for alleles in one individual/chromosome more rapidly than asexual reproduction.

 

 

 

Selection of a mate is another mechanism which greatly benefits sexual reproduction, because it allows two fit individuals to reproduce with each other, and again there is the chance of positively selected for genes landing on the same chromosome/individual. Selection of mate is also non-random on two levels in that only the fit survive, some individuals are not fit enough to survive up to reproductive age and die. This means that each individual in the population has a certain probability of reproducing with all other individuals of the opposite sex in the population (which is 0 for the ones that die before they reach reproductive age), and so it is non-random. The other way in which it is non-random is by preference genes, I won't go into that in detail but it makes the probability of reproducing with all individuals that survive to reproductive age to also be non-random and vary.

 

I would be willing to bet there is a very high correlation (approaching 100%) between high average time interval between generations (or average age of reproduction) of species and sexual reproduction, and also the correlation will breakdown as the time value falls as the benefit of sexual reproduction can be given up without hindering the species' capacity to evolve due to low generation times. If this is true, it suggests sexual reproduction is better than asexual reproduction for evolution.

 

TLDR: I believe it has been mathematically shown that sexual reproduction is a better evolutionary method. I don't know any links and have not researched it however, just a guess (read it in a book).

Edited September 7, 2012 by jp255

[Ophiolite]

Where in that lengthy piece do you address the fact that sexual reproduction is not, as you claimed, the dominant form of reproduction? Or,alternatively, where do you provide data to demonstrate that my contention is wrong?

[jp255]

many bacteria do not exclusively reproduce asexually. Very few species in general reproduce exclusively by asexual reproduction. You think that there are less species that exclusively reproduce sexually than there are asexually? There probably is data out there to show, I have not looked to be honest. I should have included "exclusive" in my earlier post in this thread

 

When I argues about this in the other thread, I limited the argument to animals. Should have done the same here to avoid that issue. I was primarily discussing the evolutionary potential of each, only in theory though. The correlation bit at the end is most likely true, of course I am again assuming, but there probably is data on it somewhere.

[dmaiski]

you have a good point, and im horrible for not actually mentioning it (i forgot), but just cause i can...

 

there is a major disadvantage to sexual reproduction;

lets say in theory there is individual A

individual A carries a very successful mutation (3 of them, got lucky on the SNP raffle)

this mutation is multi-factorial utilising genes I on chromosome 2 J on chromosome 4 and K on chromosome 18, and only functions when one allele of each is expressed

(sickle cell anaemia, or cystic fibrosis anyone(not entirely accurate, since these only have a single gene))

A has 48 offspring (very successful indeed) but only 12.5% (6 individuals) of them have mutation I J and K (viva mendels ghost)

resulting in 75% of individuals becoming ill, since this is not a fatal mutation, these individual survive but never become reproductively active

eventually all wild type individuals die off due to this effect (the extremely successful individual manage to out compete the wild type even with high offspring loss to disease

because of the high drain on the resources, the extremely successful mutants cannot reproduce as efficiently,

and the successful mutants do mate with the reproductively inactive sick individuals lowering this number even more

at this point the chance that a successful individual will be born is (from a mating of 2 mutants) 6.75% with another 6.75% for a wild type

this will cause said extremely successful mutation to die out, most likely taking the whole species with it

 

ofcource this is a nightmare scenario, but it has happened before even in humans (though not to such an extent)

also recombination could happen in this case to put all 3 or even only 2 genes on one chromosome making this mutation successful

simply put sexual reproduction is great, it averages the population to the point where no individual is better or worse then the next,

but it has a nasty habit of picking up the really bad mutations (which have a benefit when only 1 allele exists, or some other qualifier) and spreading them absolutely everywhere

 

(im just standing here whistling, polishing mah cannon balls, don' mind the cannon. move along, move along...)

 

believe it or not im actually a fan of sexual reproduction but knowing its weakness when compared to asexual is nice

each system has its own advantages, and neither system is truly superior in all situations

 

a species with an extremely fast reproductive rate will benefit from asexual reproduction, since it allows for natural selection on a mass scale and a good trait will replace a bad one in a few generations (for E.coli this could be as short as 1-2 hours) and allows fast adaptation, and simultaneous selection of several different mutations (which in tern compete with each other to find the best, and then repeat the cycle)

but this system is simply not conducive to producing multicellular organisms, they simply take too long to grow for such a carelessly efficient method of evolution(E.coli is technically so biologically superior to say H.sapien that if we were in direct competition we would die out in a single generation, simply because by the time we got to minimum reproductive age(11years, or 6 million minutes) there would be, at least, 200 thousand E.coli for each start individual, lucky were not in direct competition and, way to big to bother E.coli)

 

for species with very slow reproduction, sexual reproduction is necessary, it allows the dissemination of a good mutation over the whole species in a short(er) amount of time, 5-6 generations if its really good and there’s high selection pressure, really long-never if there is a low selection pressure (humans are a great example of this)

its major problem is that it prevents high speed evolution when the selection pressure is low and instead starts picking up whatever mutations happen to be lying around and incorporates them all into the genome.

 

 

[jp255]

but it has a nasty habit of picking up the really bad mutations (which have a benefit when only 1 allele exists, or some other qualifier) and spreading them absolutely everywhere

 

I'd be careful when saying that sexual reproduction is more sensitive to negatively selected mutations than asexual reproduction. Sexual reproduction allows for the loss of harmful mutations because only 50% of an individuals genetic material is passed on to offspring, whereas asexual reproduction does not allow for this as 100% genetic material is passed on. Also, you should completely ignore humans and domesticated animals when you think about this because medicine severley reduces the selection pressures that would be faced in the wild. In the wild when there is high selection against deleterious alleles, it will not take many generations to get rid of.

 

Also, Sexual reproduction can unlink negatively selected alleles from positively selected alleles that are on the same chromosome by recombination. Now consider this scenario. A positively selected mutation and a negatively selected for mutation occur on the same chromosome, assume that the individual is fit enough to reproduce. In a sexually reproducing population, the mutations can be unlinked from each other, but in an asexually reproducing population they can only be unlinked by a freak mutation reversion. Overall it is easier for a sexually reproducing population to unlink bad and good mutations.

 

 

each system has its own advantages, and neither system is truly superior in all situations

 

Except sexual reproduction is (currently) better than asexual reproduction, overall. Does this mean that asexual reproduction cannot be better though? Just because a particular feature/trait might be prevalent/fixed in a species does not mean that it is the best possible solution. Maybe maths can give an answer to this question someday.

[dmaiski]

Except sexual reproduction is (currently) better than asexual reproduction, overall. Does this mean that asexual reproduction cannot be better though? Just because a particular feature/trait might be prevalent/fixed in a species does not mean that it is the best possible solution. Maybe maths can give an answer to this question someday.

 

how exactly are you quantifying better?

from a size and complexity point of view, sexual is better (it did make dinosaurs and elephants)

from an efficiency point of view, the bacteria in your intestinal tract is a fair amount more efficient and refined then you are

examples: human DNA is 99% junk, bacterial DNA is usually less then 10% junk

a bacterial colony (as an structure) is immortal, humans aren’t

there is such a wide diversity of bacterial life, that we don’t even know most of it, almost all mammalian life comes with 2 forelegs 2 hind legs 1 head and 1 tail with very little deviation

(i limited this point to mammals TLDW)

 

 

"but it has a nasty habit of picking up the really bad mutations (which have a benefit when only 1 allele exists, or some other qualifier) and spreading them absolutely everywhere"

 

by "picking up" i was referring to the habit of sexual reproduction to positively select bad or inefficient traits when given the chance, especially in more "advanced" species where "physical attraction" can ignore the reasonable and well tested system of natural selection (why else do peacocks have such huge and unwieldy tails... they definitely aren’t aerodynamically viable)

 

 

[jp255]

how exactly are you quantifying better?

 

The number of generations it takes for a gene to become optimised. Essentially, the ratio, number of generations spent evolving:fitness increase of a gene. This accounts for the extreme variation between species' average reproductive age. Have you ever calculated the number of generations a bacteria can reach before the average human reproduces once? and have you ever calculated the number of offspring one bacteria can have before the average human can have one? and finally, ever calculated the number of tested mutations (natural selection would have already acted on them) that have occured within the bacterial offspring before a human even gets the chance to produce one offspring with around 60-120 mutations? This is the major weakness of your argument which compares mammal adaptions to bacterial adaptions, you are not taking into account this extremely large difference! We might have had the same amount of time to evolve since the last common ancestor but have we had the same number of generations as bacteria since then(and therefore same number of germline mutation opportunities)? This could also partly explain the difference in observed diversity can it not?

 

You're comparing apples and oranges, it is meaningless to say bacteria are more diverse than mammals when this difference of evolutionary potential is not accounted for. This is what I am arguing for, that exclusive sexual reproduction is more efficient in terms of evolutionary potential than exclusive asexual reproduction after taking into account average reproduction age/number of generations. It is more likely to be efficient because of the reasons I stated in an earlier post. In order to quantify the magnitude of difference between the evolutionary potential of each reproductive method, a mathematical model is required, but this is only an estimate as big assumptions have to be made for the sake of simplifying the problem.

 

by "picking up" i was referring to the habit of sexual reproduction to positively select bad or inefficient traits when given the chance, especially in more "advanced" species where "physical attraction" can ignore the reasonable and well tested system of natural selection (why else do peacocks have such huge and unwieldy tails... they definitely aren’t aerodynamically viable)

 

That sentence contains a big error. You cannot say that a bad trait "ignores" natural selection. Traits which contribute to differential survival/reproduction (you said "bad" traits) will rise or fall in frequency, this is natural selection. Therefore the example you use occured due to natural selection. Physical attraction itself is under selection. Your argument could be an advantage for sexual reproduction anyway, because physical attraction might have biased reproduction towards the fittest individuals. If you still stand with your claim that natural selection is ignored and bad traits rise to high frequency despite them being bad in sexually reproducing populations, then how do you propose the traits became so prevalent?

[dmaiski]

jp if you want to do an experiment to see how quickly a bacteria optimizes its genome its quite simple

1 take a wild type bacteria

2 mutate it

3 grow it in some form of medium

 

even if the mutation is as small as some extra genes for making it green,

without a selection marker, these genes will be dumped by the bacteria in a mater of 3-5 generations, and it will return to the wild type

 

its not really a mechanisim of the reproductive process but rather verry straight forward natural selection of more benificial traits

 

 

 

 

to the natural selection argument, i am looking at natural selection from a hypothetical point of view as to which traits are most beneficial to an organism in terms of ability to acquire food, evade predators, and simply survive.

many sexually attractive traits provided none of these benefits, and often are detrimental, thus i label them bad traits, since they make the individual less fit to survive

they are maintained in the population because even though they are less fit to survive they are more reproductively active

thus the "bad" trait is passed on instead of the "good" trait lowering the overall survivability of the species

(this again can be demonstrated by putting these individuals with "bad" traits in direct competition with individuals with "good" traits in an environment with high evolutionary pressures, in this case the individuals with "bad" traits die out in 1-2 generations)

sexual reproduction, by its nature, encourages production of these "bad" traits whenever the evolutionary pressures are low, and because sexual reproduction transfers genes to other individuals, this trait is spread through out the population rapidly

 

 

 

 

thats the only real disadvantage to sexual reproduction

to put it in verry simple terms:

 

asexual reproduction has 2 choises

1 keep the trait (if its good)

2 eliminate it (if its bad)

great for refining your genetic code

 

sexual reproduction(of any type) has 3 choises

1 keep the trait (it its good)

2 keep the trait but put it in storage (if its bad) (this is, in part, the source of all the junk in our genome)

3 eliminate the trait (only if the trait is fatal)

great for making new variations on the same and improving on the old

but for evry new "good" mutation you will get 1000 "bad" or "neutral" mutations

and option 2 will keep all that junk in a semi active form somewhere in the genome

 

 

[jp255]

jp if you want to do an experiment to see how quickly a bacteria optimizes its genome its quite simple

1 take a wild type bacteria

2 mutate it

3 grow it in some form of medium

 

even if the mutation is as small as some extra genes for making it green,

without a selection marker, these genes will be dumped by the bacteria in a mater of 3-5 generations, and it will return to the wild type

 

its not really a mechanisim of the reproductive process but rather verry straight forward natural selection of more benificial traits

 

This isn't relevant. You were questioning what I meant by sexual is better, and you provided examples of bacteria being more diverse. I then was trying to point out to you that before humans/animals even get the chance to change once, bacteria would have already had the opportunity to evolve a lot. average generation time for human 20-25 years? average generation time for bacteria: 2-3 hours?

 

It is likely that sexual reproduction is a more efficient method of evolution than asexual reproduction over a set number of generations. That is what I've been arguing for.

 

i am looking at natural selection from a hypothetical point of view

Except you are not considering all the possibilities.

 

to the natural selection argument, i am looking at natural selection from a hypothetical point of view as to which traits are most beneficial to an organism in terms of ability to acquire food, evade predators, and simply survive.

many sexually attractive traits provided none of these benefits, and often are detrimental, thus i label them bad traits, since they make the individual less fit to survive

they are maintained in the population because even though they are less fit to survive they are more reproductively active

thus the "bad" trait is passed on instead of the "good" trait lowering the overall survivability of the species

 

You calling a trait which increases an individuals' chances of reproducing "bad". This trait will be positively selected for, because it it increases reproductive success. Also, how do you know that sexual attraction was not under positive selection itself? that it is selected for because individuals that survive to reproductive age that possess traits that lower their chance of survival means that they are fitter than an individual without such traits. In other words, how do you know that sexual attraction did not rise to fixation to take advantage of non-uniform fitness of potential mates in the population. If you had considered this possibility, then these traits are considered good. Natural selection isn't confused about what is good and what is bad, any trait which increases survival/reproduction is good and will likely rise in frequency and vice versa. Again, everything about these scenarios suggests that actually these traits are good, because they have evolved and survived for long periods of time and increased in frequency.

 

asexual reproduction has 2 choises

1 keep the trait (if its good)

2 eliminate it (if its bad)

great for refining your genetic code

 

sexual reproduction(of any type) has 3 choises

1 keep the trait (it its good)

2 keep the trait but put it in storage (if its bad) (this is, in part, the source of all the junk in our genome)

3 eliminate the trait (only if the trait is fatal)

great for making new variations on the same and improving on the old

but for evry new "good" mutation you will get 1000 "bad" or "neutral" mutations

and option 2 will keep all that junk in a semi active form somewhere in the genome

 

 

Read my previous explanation again? elimination of a trait in explicit asexual populations is death or freak mutation reversion, in a unicellular species with short generation time this is not costly, nor in a multicellular with short generation time. The cost of elimination of a trait for an explicitly asexual population with a very high generation time of years is a lot higher, whereas the cost of elimination of a trait in a sexual population with very high generation time is not as high.

 

Do you agree that generation time and the rate of evolution are related, at least in multicellular species that rely on germline mutation to evolve? If you do then you should expect sexual reproduction to be more efficient because most species with high generation times of years explicitly reproduce sexually, and there almost none which explicitly reproduce asexually.

[dmaiski]

a species with an extremely fast reproductive rate will benefit from asexual reproduction, since it allows for natural selection on a mass scale and a good trait will replace a bad one in a few generations (for E.coli this could be as short as 1-2 hours) and allows fast adaptation, and simultaneous selection of several different mutations (which in tern compete with each other to find the best, and then repeat the cycle)

but this system is simply not conducive to producing multicellular organisms, they simply take too long to grow for such a carelessly efficient method of evolution

 

i did say this?

 

you are arguing against my point of view when it already agrees with yours

[dmaiski]

a species with an extremely fast reproductive rate will benefit from asexual reproduction, since it allows for natural selection on a mass scale and a good trait will replace a bad one in a few generations (for E.coli this could be as short as 1-2 hours) and allows fast adaptation, and simultaneous selection of several different mutations (which in tern compete with each other to find the best, and then repeat the cycle)

but this system is simply not conducive to producing multicellular organisms, they simply take too long to grow for such a carelessly efficient method of evolution

 

i did say this?

 

you are arguing against my point of view when it already agrees with yours

[jp255]

I was arguing against post 17 and I am arguing against some other arguments of yours in post 19. Truth be told I skipped over that quote, I didn't really get the first half of post 15, and I was under the impression that you were still skeptical about sexual reproduction being a better method for evolution from #17 and 19.

 

Ok, if your onboard with sexual > asexual. Then respond to my previous post where I criticise your thinking on sexual attraction and inefficient traits that you think sexual reproduction produces (that asexual does not).

 

 

[dmaiski]

i cant say sexual attraction is bad because its not, but to say it is perfect, or a truly superior system is silly and naive

 

sexual attraction promotes reproduction, in turn the traits that cause sexual attraction get promoted in the population, these traits are then over expressed, elaborated on, and generally made more prominent

 

this is a good thing, it allowed for humans to be born from bacteria

(if you were to base it on the observation that true asexual reproduction dose not occur in many multicellular species)

 

it is conversely a bad thing as well, it causes these sexual traits to become more important then useful traits, such as: intelligence, longer life span, cancer protection, eye sight, an efficient immune system, and many others

 

what traits are improved?

well there's: penis size, libido, and aggression, in males. (imagine a dog trying to screw your leg... thats sexual atraction at work)

in females there's: lower muscle mass, large mammaries(breasts), menstrual bleeding(its a trait that humans have developed and other animals wisely abstained from, its probably relevant)

 

im fairly sure that there are many more but those are the ones i thought of on the spot

these traits serve no biological advantage other then sexual attraction

they have also gotten many humans killed, but still persist in the population

 

(im sorry but although these are true statements they are not particularly pleasant, i chose humans as an example because i know a lot about them (im mostly human myself) and because they are easy to point fingers at (the statement dicks on legs is a valid descriptor of mankind))

 

(the second paragraph when looked at through my mind):

 

DO NOT READ THIS SECTION BEFORE YOU READ THE TOP FIRST

 

IT IS A RANT!

 

sexual attraction promotes reproduction (a good thing, generally), in turn the traits that cause sexual attraction get promoted in the population(so so... the key word here is SEXUAL ATTRACTION, not REPRODUCTION) these traits are then over expressed (not a good thing, especially when the trait serves no beneficial purpose), elaborated on (even worse, you make a large protrusion, then make it bigger, coat it with fur, give it a poor circulatory system, and make it shoot glucose water with protein at people), and generally made more prominent (probably not a good idea, focus all your evolutionary prowess on making a truly and utterly useless set of appendages, just so you can attract a mate (attracting a mate is a good thing, wasting tonnes of energy to do it, not so much)

 

DO NOT READ THIS SECTION BEFORE YOU READ THE TOP FIRST

 

IT IS A RANT!

 

Edited September 12, 2012 by dmaiski

[jp255]

sexual attraction promotes reproduction, in turn the traits that cause sexual attraction get promoted in the population, these traits are then over expressed, elaborated on, and generally made more prominent

 

Sexual attraction results in non-random mate choice. As a trait, sexual attraction will only increase in frequency if individuals which display non-random mate choice have a significantly greater number of offspring that reach reproductive age (or by fluke genetic drift). There is a difference between this and your statement. It is that sexual attraction can be selected for itself because it can increase the probability that an individual will mate with a fit partner (higher fitness than population average). It can, but not always, rise in frequency because it allows for detection of non-uniform population fitness so reproduction can be limited to partners at the high end of the fitness distribution (occurs when sexually selected for trait is associated with higher fitness).

 

An example of such an occurence is found in this paper Call duration as an indicator of genetic quality in male gray tree frogs. Science 280: 1928-1930 on this site http://www.unc.edu/~welcha/ . I couldn't find a direct link.

 

The link is an example of this possibility I described. To show it in humans is next to impossible, fitness is not so applicable to humans anymore and this is complicated to determine. It would have to be shown back when we were hunter gatherers to provide evidence of sexual attraction providing fitness benefits to offspring, this is practically impossible. Non-random and non-uniform sexual attraction can be shown however, at least showing the possibility for biased mate choice in favour of fit individuals is there.

 

it is conversely a bad thing as well, it causes these sexual traits to become more important then useful traits, such as: intelligence, longer life span, cancer protection, eye sight, an efficient immune system, and many others

 

Considering the stuff above, to say that sexual traits are more important than useful traits is stupid. There is also the possibility that sexual attraction to individuals with these traits might have occured, and this can't really be denied.

 

TLDR: you might think that the trait serves no beneficial purpose, but if it is associated to fit individuals then the opportunity for sexual attraction to be positively selected for (and therefore useful) is there. A sexually selected for trait shouldn't be termed "not beneficial" until it is found not to be associated to fit individuals. Sexual selection can be greatly advantageous if a trait that is highly associated to fit individuals is found.