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    How Female Promiscuity Can Be The Smart Move In Evolution
    By Catarina Amorim | October 14th 2012 01:41 PM | 34 comments | Print | E-mail | Track Comments
    About Catarina

    After many years as a scientist (immunology) at Oxford University I moved into scientific journalism and public understanding of science. I am...

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    Researchers have discovered that females with multiple sexual partners can be more fertile than those that are monogamous, and this because of an “overproduction” of sons.  The study,  published as a provisional article but already one of the most accessed in BCM Evolutionary Biology, helps to explain a puzzle haunting evolutionary biologist for decades: why so many females chase multiple sexual partners in a mating season, when this is costly and dangerous, and one is enough to fertilize all her eggs.

    The discovery that the behavior increases their fertility (and allows them to change the offspring gender) can now explain why. After all, in evolution, success is all about passing one’s genes to future generations, and the more descendants you have higher are the chances of that to happen. 

     In the last decades scientists have discovered that multiple mating is widespread, even among those species once seen as the epitome of monogamy, like swans and penguins. And also that males and females both chase multiple partners. While this makes sense to males - since the more they mate the more descendants they have to carry their genes – with females the case is very different. Not only they produce a limited number of eggs per breeding cycle but the practice is also particularly dangerous to females. Still, more and more cases of species where females actively pursue polyandry (female multiple mating) are being discovered.

    So why is this?  Everything in nature is about costs and advantages, so a behavior, such as polyandry, is only be pursued if its benefits outweigh its costs. Ultimately, this means that it has to improve the individual (in this case the female’s) fitness (ability to pass its genes to future generations). And for polyandry there are two types of benefits possible: direct (when the female is directly benefited, for example with increased fecundity or longevity) or indirect (when is the next generation that gets the advantages by becoming for example more attractive or stronger, all characteristics that improve their chances to reproduce). The idea being that if one or both types compensate the costs of polyandry to females, then its persistence in nature can be explained. 

     And in fact several cases of female-initiated polyandry with indirect benefits (so leading to “improved” offsprings) have already been discovered, and some even believe that they are enough to offset polyandry costs. That , however, remains to proved. 

     And this is where Miguel Barbosa from University of Aveiro, Anne E Magurran and Maria Dornelas from University of St Andrews and Sean Connolly and Mizue Hisano from James Cook University enter. They developed an approach to track the fate of the offspring across to two generations (since the number of “grand-offspring” to achieve maturity is an efficient measure of fitness), and which, crucially, distinguished between direct and indirect benefits (an issue not clear in previous works) to help clarify which ones are relevant to female polyandry. And used Trinidadian guppies, a small and colorful freshwater fish where multiple mating is common among both sexes, and females often initiate polyandry despite the males bringing nothing (no help) but sperm to reproduction. 


    Guppy male (Poeciliidae- Poecilia reticulata). Credit: Ciência Viva - Agência Nacional para a Cultura Científica e Tecnológica

     The researchers started by mating the females with either one or multiple males, and followed the results for two generations, looking at both their first offspring (their “children”) and their second (the “grandchildren”). And found that polyandrous (multiple mating) females were much more fertile than monogamous ones with about 1.5 more “grand-children”. And more, that this was due to them having much more, an extraordinary 83% more, viable “sons” than females with only one sexual partner. This agrees with evolutionary theory’s prediction that when conditions are good, females invest more in the sex with greater variability, which in this case are males. After all males are not limited in number of children (contrary to females), so more sons mean extra descendants. 


     These two discovered “paybacks” of polyandry – more descendants and an ability to manipulate the sex ratio of the offspring for their advantage – are be no doubt important “weapons” for the evolutionary success of a female and help to explain why they risk so much to chase even those apparently worthless guppy males. 

     But contrary to previous studies Barbosa and colleagues found no differences between monogamous and polyandrous mothers on those offspring characteristics linked to indirect benefits, such as size at birth, growth rate, time to sexual maturation and survival. This is probably due to different environmental conditions though, as when not under of stress, animals tend to increase their overall numbers instead of changing their characteristics.

     “These results have broad implications for evolutionary studies”, says Miguel Barbosa, the first author of the work, “there is still an intrinsic idea that female reproductive success is independent of number of mates,. This follows the suggestion that females are the passive sex with a limited ability to change the course of the mating process. Our results together with previous studies, refute this, and show the females on the driving seat of the reproductive process. “ 

    Citation: Miguel Barbosa, Sean R Connolly, Mizue Hisano, Maria Dornelas and Anne E Magurran, 'Fitness consequences of female multiple mating: A direct test of indirect benefits', BMC Evolutionary Biology 2012, 12:185 doi:10.1186/1471-2148-12-185 

    Comments

    Bonny Bonobo alias Brat
    The researchers started by mating the females with either one or multiple males, and followed the results for two generations, looking at both their first offspring (their “children”) and their second (the “grandchildren”). And found that polyandrous (multiple mating) females were much more fertile than monogamous ones with about 1.5 more “grand-children”. And more, that this was due to them having much more, an extraordinary 83% more, viable “sons” than females with only one sexual partner. This agrees with evolutionary theory’s prediction that when conditions are good, females invest more in the sex with greater variability, which in this case are males. After all males are not limited in number of children (contrary to females), so more sons mean extra descendants.
    I'm a bit confused, the multiply mated females have more offspring and they also have more sons so that means they are more fertile then singly mated females? The paper says that :-
    Two types of benefits are commonly used to explain the adaptive value of multiple mating: non-genetic benefits (direct/first generation) [1] and genetic benefits (indirect/second generation) [8]. Direct benefits derive from the quality of the sperm
    of certain males that may increase female fecundity, longevity, or mating rate [1].
    Additionally, if males transfer insufficient sperm, females may mate multiply to ensure all eggs are fertilized, hence obtaining fecundity benefits [9].
    Surely all this is really showing is that some males have better quality sperm than other males and if a female mates with multiple males she has a better chance of having sex with a more fertile male than if she mates with a single male? If it was possible to identify the males with better quality sperm and assign them all to the females who mate with a single male group then is it possible that multiple mating females might then lose that advantage? Also does repeated mating wash out the sperm of previous males and if so wouldn't that make the likelihood of more male offspring more likely in the multiple mating group as male XY sperm have an advantage over female XX sperm in those conditions?
    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine
    amorca
    Hi Helen, multiple mating females (MMF) have more viable sons in the 1st offspring than monogamous females. Thus then having more grand-offspring (2nd generation) , which is a good measure of the females' fitness. 
    The key to having more sons should be linked to have access to more sperm,  but exactly how this then determines  the more males thing is still not clear. It could be different allocations of resources for example like shown in thsi article 

    article _http://onlinelibrary.wiley.com/doi/10.1111/j.1095-8312.2010.01425.x/abstract
    Gerhard Adam
    Why does this remind me of epicycles?  Again, the notion that the genes are in control?

    The simple reality is that it is NOT a dominant trait nor characteristic since it is not the behavior that exists at any fundamental level.
    This agrees with evolutionary theory’s prediction that when conditions are good, females invest more in the sex with greater variability, which in this case are males.
    Great.  Now what is the mechanism by which the female "chooses" this investment?  Are the researchers suggesting that the genes know when conditions are good?  Is this epigenetic [which argues against the genes doing anything]?

    In short, the simple reality is that this is purely a function of how many eggs can be fertilized.  If there are unfertilized eggs available, then clearly there is an advantage to polyandry, if not, then there isn't.  Since guppies depend on sheer numbers for survivors, then obviously the maximum fertilization would ensure the highest possible number of surviving offspring. 
    Our results together with previous studies, refute this, and show the females on the driving seat of the reproductive process.
    They're only NOW discovering this? 
    ...there is still an intrinsic idea that female reproductive success is independent of number of mates...
    It may well be, depending on the species.  If there is only one egg to be fertilized, then multiple mates makes no sense.  If there are multiple eggs and multiple means by which they can be fertilized, then multiple matings makes sense.  This has been known even in dogs for centuries.

    It is also clearly a function of resources necessary in rearing offspring, which is a significantly greater limitation than the number of fertilized eggs.  The overwhelming majority of "higher" animals aren't restricted by their reproductive system.  They are restricted by the energy and commitment necessary to successfully raise their offspring to adulthood.
    Mundus vult decipi
    amorca
    Actually I cannot be bothered to answer. There is a lot of literature on polyandry , and a lot of authors that disagree with you so maybe you could argue with them that is all about the sheer number of eggs. A good example are birds that have what 4, 5 eggs? and polyandry driven by females still exist - actually birds have a case of sex-ratio switch to males exactly with female initiated polayndry 
    Gerhard Adam
    The third type of mating system, where the traditional sex-roles are reversed, found in roughly 0.4% of all bird species, is polyandry.  In this system, females mate and lay eggs with multiple males over the course of a breeding season, leaving males to incubate the eggs and raise the chicks.
    http://10000birds.com/polyandry-and-polygynandary-on-the-tundra.htm
    However, the potential benefits of polyandry remain controversial, particularly in birds where recent reviews have suggested that females gain few genetic benefits from extra-pair mating.

    Our results suggest that the benefits of polyandry may only be clear when considering both the number of mates females acquire and their ability to modify the outcome of sexual conflict.
    http://onlinelibrary.wiley.com/doi/10.1111/j.1365-294X.2010.04640.x/abstract
    Although most species of birds show biparental care and social monogamy, many of the best-studied species regularly exhibit uniparental care, where one parent deserts the clutch and their mate is left to provide care alone (Lack 1968; Oring 1982; Davies 1991). In the majority of these cases, it is the male that does the deserting and the female that provides the care. In such species the males are often socially polygynous.

    ...the sex roles are ‘reversed’ and it is the female that deserts, leaving the male to care for the offspring. Where this occurs females are typically socially polyandrous.
    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1692940/pdf/11958697.pdf
    Since the condition bears virtually no resemblance to that of guppies, and it doesn't occur very frequently, it isn't much of an argument.
    A good example are birds that have what 4, 5 eggs?
    Not at all, because the point is that the female can lay 4 or 5 eggs, multiple times because the male is left to tend to them.  It is expressly a matter of increased egg-laying. 

    Polyandry makes no sense unless there are an increased number of eggs to be fertilized, or there are additional resources a male can provide for care.  Once all eggs are fertilized the female's behavior is irrelevant, since it will not change the fitness one iota.  The only possible impact is if there is a resource dependency on the male.
    Mundus vult decipi
    amorca
    First,  polyandry definition is multiple mating for breeding cycle , so it's not after putting the eggs that they go after the other males. 
    And the practice is more than just eggs or parental care  even in birds as you can  in  this paper where it allows  changes of the progeny's sex-ratio

    Extra-pair young in house wren broods are more likely to be male than female

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2677618/



    amorca
    Gerhard I left you a note in the end of the page
    Gerhard Adam
    These two discovered “paybacks” of polyandry – more descendants and an ability to manipulate the sex ratio of the offspring for their advantage – are be no doubt important “weapons” for the evolutionary success of a female and help to explain why they risk so much to chase even those apparently worthless guppy males.
    Worthless?  Is this supposed to be science or a soap opera?  Since females can store balls of spermatozoa for up to a year, then it stands to reason that she has the incentive [and mechanisms] to acquire sperm for later fertilization.

    Moreover, guppies are especially prone to the problems of live birth, since mature guppies may well eat the fry, so it is clearly important to maximize the number born during any given cycle to improve the likelihood that some will survive.

    I find this entire statement to be seriously flawed, since even suggesting that there is a distinction between the "evolutionary success of a female" versus that of a male is introducing an element of anthropomorphism that simply confuses the issue, and attempts to place a value judgement on fish that is inappropriate and irrelevant.  It should be obvious that the entire species is threatened if the sex ratio is wrong.


    Mundus vult decipi
    Bonny Bonobo alias Brat
    Worthless?  Is this supposed to be science or a soap opera?  Since females can store balls of spermatozoa for up to a year, then it stands to reason that she has the incentive [and mechanisms] to acquire sperm for later fertilization.
    Calm down Gerhard, its sounds more like a porn movie than a soap opera and as only 11% of men apparently don't watch porn there's no need to get so high and mighty here, even if it is a science website! Now which female guppy looks like she's going to have the most offspring, the one on the left with the 3 males (one hidden) or the one on the right with the one male?



    Well, the one on the left died later because the newly acquired, spectacular looking, orange, male guppy in the middle gave her a fatal disease. I have kept guppies for a long time and I had no idea they could store sperm for a year! The photos of the guppies were taken from this website.
    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine
    Gerhard Adam
    ...high and mighty...
    It isn't a question of being "high and mighty" nor of considering whether it is "porn" or a "soap opera".  The simple fact is that words like "worthless" have no place in a discussion about an animal's breeding patterns.  If the point is to turn this into a sexist debate, then by all means, let's not pretend that the agenda is anything except arguing about human sexual conflicts.  This type of human-value laden discussion contributes nothing useful to biology.

    I'm still at a loss to understand how polyandry translates into promiscuity [and all the value baggage that word invokes].
    I have kept guppies for a long time and I had no idea they could store sperm for a year!
    http://www.advancedaquarist.com/blog/a-solitary-female-guppy
    http://www.fishlore.com/fishforum/guppy/82156-how-long-can-guppies-store-sperm.html
    Mundus vult decipi
    Bonny Bonobo alias Brat
    I have kept guppies for a long time and I had no idea they could store sperm for a year!
    ttp://www.advancedaquarist.com/blog/a-solitary-female-guppy
    http://www.fishlore.com/fishforum/guppy/82156-how-long-can-guppies-store-sperm.html
    Six months was the longest claim for female guppie sperm storage that I could find in those links.
    If the point is to turn this into a sexist debate, then by all means, let's not pretend that the agenda is anything except arguing about human sexual conflicts.  This type of human-value laden discussion contributes nothing useful to biology.
    I think you're being most unfair Gerhard, just because Catarina quite jokingly described a male guppie as 'worthless' within an experiment measuring female guppie's fertility and polyandrous mating with multiple males. Do you think you may have been a male guppie in a previous life?
    I'm still at a loss to understand how polyandry translates into promiscuity [and all the value baggage that word invokes].
    You must be joking right? Catarina said earlier that swans and penguins are perceived as being the epitomy of monogamy by mating for life, when in reality they are actually polyandrous, so surely that makes them the equivalent of promiscuous? Why are you being so critical? So many other articles here use artistic or poetic license to spice up descriptions of scientific experiments and concepts but you don't usually criticise them.
    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine
    Hank
    descriptions of scientific experiments and concepts but you don't usually criticise them.
    I just said the same thing to him in another article so I guess, errrr, he does actually criticize them. What would be funny is if we could find a Gerhard to Gerhard Gerhard's articles.  I am not sure of the math, but I think it would warp the very fabric of time and space.
    Bonny Bonobo alias Brat
    Ha ha, look out Hank, he might get mad soon!


    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine
    Gerhard Adam
    I seriously doubt that you would be nearly as understanding if the article were entitled "Female Rape Conveys Evolutionary Benefits".  Even if the entire article were about bedbugs, you'd be incensed.
    http://www.pnas.org/content/98/10/5683.full.pdf
    Mundus vult decipi
    Bonny Bonobo alias Brat
    Well you're right but for the wrong reasons. I probably would not be understanding and would dispute an article titled 'Female Rape Conveys Evolutionary Benefits' if as in the article that you linked to, the evidence showed that rape, like the traumatic insemination of female bed bugs, Cimex lectularius, via a unique mode of copulation, during which the male pierces the female’s abdominal wall with his external genitalia and inseminates into her body cavity, did not convey evolutionary benefits, and instead it resulted in a sexual conflict of interest and therefore no evolutionary benefits. The results in the bed bug study showed :-
    (i) last-male sperm precedence, (ii) suboptimal remating frequencies for the maintenance of female fertility, and (iii) reduced longevity and reproductive success in females. Experimental females did not receive indirect benefits from multiple mating. We conclude that traumatic insemination is probably a coercive male copulatory strategy that results in a sexual conflict of interests.
    It's also interesting that this paper says that recently 'there has been a shift away from the view that the sexes share a common goal during reproduction and a move toward the concept that males and females are often in conflict over reproductive outcomes'.
    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine
    Gerhard Adam
    Of course it conveys an evolutionary benefit; to the males.  That's no different than the argument made in this paper that polyandry conveys an evolutionary benefit to females.

    Again, my point is not to argue about the sexual proclivities of bedbugs, but to illustrate how a title can be used to create an impression not borne out by the article.
    Mundus vult decipi
    Bonny Bonobo alias Brat
    There is no evolutionary benefit for the female or the species as a whole, for the female bed bug to be raped and have her body pierced and then die prematurely and I doubt if it is really evolutionary beneficial for the rapist male bed bug compared to a non-rapist bed bug, if he were to exist. There is however an evolutionary benefit for the guppies as a whole, both males and females, for the female guppie to be promiscuous, sorry I mean polyandrous (keep your hat on) compared to a monogamous female guppie!
    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine
    Gerhard Adam
    There is no evolutionary benefit for the female or the species as a whole, for the female bed bug to be raped and have her body pierced and then die prematurely...
    What do you base that declaration on?  What makes you think she dies?  The truth of the matter is that it can be beneficial to the males, since even the female's body is set to "allow" traumatic insemination so that the sperm migrate to the ovaries.  Without such an adaptation, then it really would be a waste of time.  However, the fact that it exists, indicates that it works.

    http://www.ncbi.nlm.nih.gov/pmc/articles/PMC33273/
    Mundus vult decipi
    Bonny Bonobo alias Brat
    The results in the bed bug study showed :-(i) last-male sperm precedence, (ii) suboptimal remating frequencies for the maintenance of female fertility, and (iii) reduced longevity and reproductive success in females.
    My article about researchers identifying a potential blue green algae cause & L-Serine treatment for Lou Gehrig's ALS, MND, Parkinsons & Alzheimers is at http://www.science20.com/forums/medicine
    Gerhard Adam
    Reduced longevity does NOT mean death.  It simply means an earlier death.  Again, female success in this is irrelevant.
    Mundus vult decipi
    amorca
    Gerhard maybe you should read more scientific articles instead of spending so long here - often in them the word promiscuity is used as the equivalent of polyagamy both in females and males. And to be honest your tone is ridiculous in what is supposed to be a friendly discussion, 
    And the word worthless was about males  not giving  parental care and to be honest I write my articles as I decide to, so back off or if you have comments  be less aggressive. And sort your anger 
    Gerhard Adam
    ...often in them the word promiscuity is used as the equivalent of polyagamy both in females and males.
    Actually it isn't.  Promiscuity involves a casual mating, whereas polyandry and polygamy can involve serial events of pair-bonding, whereas promiscuity never involves pair-bonding.  So a female can be polyandrous but still be bonded serially or simultaneously with individual males. 

    Mundus vult decipi
    amorca
    In fact, but that is not what I said , all promiscuous females are polygamous and often it is used one or the other in studies where promiscuous females are being researched. And guppies are both, so what is exactly your problem with me using the word? I
    Out of curiosity, alleged evolutionary benefits aside, why does polyandry result in more male births? I don't know anything about it, but it seems like it's a matter of which sperm finds an egg. I can see how there could be variations in the number of X vs Y bearing sperm, or how X sperm might outperform Y sperm - but why should multiple donors matter? What's the mechanism?

    amorca
    Like in humans, guppies' male chromosome is Y . Multiple mating assures that you have enough sperm with the Y chromosome to assure you can  have the number of sons you need.Basically it's a question of having enough material to "play".
    Hmm. Seems to me with more mates you'd just have more sperm, with the same X-Y ratio. How does it result in a higher ratio of male births? I sorta thought it was up to the sperm to swim in there and get 'er done - the luck (and fitness) of individual sperm determines the gender. But the female selects them somehow? By blocking X-bearing sperm? Or by selectively discarding fertilized female eggs? How does she 'play?'

    And if so, whatever mechanism does that, why doesn't it just do the same with the sperm from fewer mates, or a single mate? I sorta thought there was always a surplus of sperm.

    amorca
     look at the answer to Helen's question at the beginning for some
    vongehr
    The discovery that the behavior increases their fertility (and allows them to change the offspring gender) can now explain why.
    I don't want to just pile on, but a little criticism instead of just taking a "sex" article and add "artistic or poetic license to spice up" (Helen's words) would be welcome - especially with sex-issues written by females, because criticizing them in turn leads fast to sexism charges (see above). There is too much very questionable here (I don't even want to get started), while in fact, the advantage of multiple mates for females is long well established and different for different species (sperm competition, preventing infanticide, countering incest, ... ), thus "can now be explained" belongs to the usual glamor-science writing that survives on press releases. It may get clicks, that is what evolution is of course about, but it ain't any good.
    amorca
    The perks of living in a different time zone, waking up to pages of comments. I will come back to this later , especially to those always nice and restrained  words of Gerardh. 

    And Sascha we had this discussion before, polyandry by females is not clear at all , you talk about primates that's all. Last time I asked you to go and read reviews, you obviously never got that far. By the way,  I clearly say "it  helps to explain a puzzle haunting evolutionary biologist " with the key words being "help to explain"
    vongehr
    Another one afraid to answer via the "Reply to this" button (note, just in my case, not with Gerhard) in order so I do not get notified. What are you afraid of? Oh, right, that I destroy your arguments, because you know very well that you have no chance against me. But you know what - I don't care about double faced people like you anymore. YOU go read and UNDERSTAND scientific papers for a change!
    amorca
    Seriously Sascha? Doubled faced? Afraid of you? Didn't treat you the same way as Gerhard? Do you even notice how that makes you look? 
    vongehr
    I do not care how nice-sciency-but-not-where-it-hurts kind of people perceive and distort critical voices. You go feed your audience what they crave, feel good in your mutual admiration clubs; it does no longer matter to me. Ever more people no longer trust science because of pseudo skeptics, naive scientism, and glamor science like your article and arrogant way of "discourse", but even that does no longer matter, because sooner than you can see, because of evolution that science-outreach-as-fashion-accessory careerists do not want to grasp, people no longer matter. Your answering here shows that you feel it is more important to save face than to engage in meaningful exchange with people who at least still have the willingness to learn, like Gerhard. Have fun Catarina. We all have fun in the feel good game of the infotech-age establishment, finding our niche under the science religion of the new upper class.
    amorca
    Sascha and Gerahrd since I regularly put articles here and you often make comments on them I think we need to clarify a few things

    1-     My writing style is my option, and you have nothing to do with it. Whatever I want to use some poetic liberties or not it is my problem, I don’t particularly like the way you both write, which  I tend to find pretentious and elitist, but I respect your choices. You need todo the same with mine (or anyone’s else)

    2-     The science I write about is published and peer reviewed. So if you think that you know more than the scientists that publish it, be my guests and go and publish on the subject. Nevertheless  I am always happy to receive comments and accept that you can have a different opinion. _But you have to respect what I say as well. Basically  I am open to friendly debates even if we totally disagree, but you have to accept to agree to disagree.

     What I am not happy with is:

    ·       offending comments

    ·       aggressive or patronising attitudes/comments

    And like this  website reserves the right to delete spam and offensive stuff , I will, in the future, do the same on that kind of comments in my articles.

     Now if you are really interested in the science (and all this was not just  the effects of testosterone and too much time at home in front of the computer )  bellow  are 3 articles that demonstrate what I have been saying 1- that polyandry initiated by females is still not clear (Sascha’s issue) and that the behaviour is about more than just have all eggs fertilised or parental care (Gerahd’s problem).

     And  I really think we have talked all that is to talk on this, but I look fwd to have your friendly challenging comments on my next pieces.

    Are there indirect fitnessbenefits of female extra-pair reproduction? Lifetime reproductive success ofwithin-pair and extra-pair offspring RJ Sardell, P Arcese,LF Keller, JM Reid - The American naturalist, 2012 - cat.inist.fr Résumé/Abstract Theforces driving extra-pair reproduction by socially monogamous  females, and theresulting genetic polyandry, remain unclear. A testable prediction of the  hypothesis thatextra-pair reproduction partly reflects indirect selection on females isthat ...

     [HTML] Lifetime Number of Mates Interacts with Female Age toDetermine Reproductive Success in Female Guppies JP Evans - PLOS ONE,2012 - dx.plos.org In many species,mating with multiple males confers benefits to females, but thesebenefits  may be offset by thedirect and indirect costs associated with elevated mating frequency. ..

    Estimating genetic benefits of polyandry from experimental studies: a meta-analysis Rachel A.Slatyer†, Brian S. Mautz†, Patricia R.Y. Backwell, Michael  D.Jennions* DOI: 10.1111/j.1469-185X.2011.00182.x BiologicalReviews Volume 87, Issue 1, pages 1–33, February 2012

    vongehr
    I am not going to bite this bait much either - just one little hint, as you claim that you read my articles (how would you otherwise know that my style is "elitist", something my regular readers, who very much appreciate me for being critical of elites and bringing issues down to the lay level, will scoff at):
    be my guests and go and publish on the subject
    If you had followed my posts even just sporadically, you would know that my work is all about trying to publish and having my best work being rejected for reasons that are clearly because of the corruption of the scientific method by the scientific community, read here and here for example (oh sorry, you read them already - LOL).

    BTW: that the way of writing, especially the kind of daily mail like spicing up of sex issues, is merely a choice of background color or fond size beyond criticism is surely something you cannot possibly seriously hold?!? Form shapes content.