The Material World
with Quentin Cooper

Quentin Cooper : Hello,today women who want sex with multiple partners,no you've not tuned into Jerry Springer by mistake,this is the Material World,but according to new research, it's such behaviour,rather than monogamy,which is the true nature of females,from guppies to humans.
Later on we'll look into the ambiguities of promiscuity,and assess the winners and losers in sperm competition,which thankfully isn't yet an Olympic sport.
Blame Isaac Asimov and his robots with positrons enabling them to think,blame Star Trek with it's starships powered by antimatter in containment fields,and robots with positrons enabling them to think,blame every sci-fi hero who's ever fretted about matter and anti matter,coming together and destroying the universe as we know it.
Because collectively they've ensured that antimatter manages to be very familiar as a phrase,while remaining thoroughly elusive in terms of meaning.I mean is it just a theory,can you find it or make it in the lab,or would you just destroy the universe as we know it if you did? And why does antimatter matter so much to physicists.The European particle physics laboratory near Geneva CERN has just spent millions on a factory designed to mass produce the stuff,on the line from CERN is research physicist Dr Rolf Landau,and I'm also joined on the line from Liverpool by Dr John Fry from the department of physics at Liverpool University. Rolf,nice simple one,what's antimatter? 

Rolf Landau : Well,erm,antimatter simply speaking is the mirror image of matter,so if you take...matter is made of atoms,the simplest is the hydrogen atom made of a proton and an electron,and in an antimatter universe you would have a proton with an opposite charge,a negative proton,and and a positive electron called a positron,and everything would just be inverted.

Quentin Cooper : Okay well that's the positron I've already mentioned,so that gets the Isaac Asimov reference out of the way.John anything to add on this,it's just a mirror image of our own universe?

John Fry : Yes,I mean one way of looking at it is to think of a photograph,you've got the positive and you've got a negative,so what's black looks white,what's white looks black.The other important thing about antimatter and matter is that they annihilate each other,this isn't science fiction,this is real,we see it in the laboratory,and you can see the effects of that,if you superimpose the positive and the negative photographs,you lose your structure and the whole thing just becomes a sort of grey blur.So that's an analogy for the matter and antimatter annihilating each other,and you know,we see this in hospitals,we use the PET - the positron tomograph [Positron Emission Tomography -LB] device and there the positron annihilates with an electron giving gamma rays which we detect.So you know not only is it only a tool in the laboratory,it's something we use in hospitals,something of benefit in daily life.[So it has a "use" then,for all the utilitarians? -LB] 

Quentin Cooper :  Okay you've established it's a theory and of practice,when did it first begin to develop in terms of scientific thinking?

John Fry : I think the first idea came in 1928 with a British physicist called Paul Dirac [see iotm77.wri@iotm.html@fortunecity] and then the positron was seen in experiments using a cloud chamber in 1932,so you know it's not that long ago,and then what,1955 we discovered the antiproton,and since then we've been ticking off the table of all the other possible particles,that have the mirror image of the antiparticles.

Quentin Cooper :  Rolf Landau was Dirac - and this is his second plug on Radio 4 today,I think he turned up in Melvyn Bragg's programme this morning as well [He did,which is why I transcribed it! -LB] - but was Dirac just predicting these antiparticles were possible or was he saying they were necessary in order to explain our own universe?

Rolf Landau : Well it was,I would say a purely theoretical discovery at that point,he tried to devise an equation describing the electron,and he found out that combining the laws of Relativity and Quantum Physics,the only way he could describe it properly was to postulate that also an antiparticle exists - the positron.

[It's worth noting here that such postulations are the direct results of mathematical computation,and so the presumption of existence and subsequent finding of such particles is evidence that mathematics correctly describes the universe in some core way.Whether mathematics is a tool of man or whether such particles are created as opposed to discovered, I think here leans towards the idea that such things exist and mathematics finds them,in some sense tool or part of the universe,mathematics works,and it is rather odd that any presumed deity should allow such a means to discovery.Thence we presume a God of geometry or mathematics,and we uncover that scheme,or have been creative enough to manufacture our own scheme which rival's God's.
As I said in iotm77 : Davis and Hersh say "Can we conclude that mathematics is a form of religion, and in fact the true religion?" (see also mathexp.html {Religion}) -LB]

What I think at the beginning nobody really took him seriously,but when the positron was found,then I think the whole theory took off and now we are mass producing antiprotons, positrons and all other kind of antiparticles.

Quentin Cooper : I always have this image of particle physicists as sort of galactic accountants,there always having to do kind of desperately trying to balance the books by creating something to sort of say "Oh that doesn't quite add up,so oh what we need is one of these".

[This is indicative of the creation/discovery angle I was getting at. Like the table of the elements (see www.chemicalelements.com) the presumption is made of a missing piece of the jigsaw on the strength of what we know of our side of it.Since our universe is mainly matter,antimatter has to be created (or discovered) in order to check if it can exist.
There must be some reason why our universe is mostly matter,and this supposes that there is a net "imbalance" or shift in favour of matter,that tends to suggest the two things are not complete opposites of one another,or if they are,that a primal choice was made favouring matter. In "The Left Hand of the Electron" Asimov (referred to earlier) takes up this point. Indeed is not our DNA spiralling in one distinct direction? (see world25.rtf,edge6.rtf) -LB]

So having come up with a theory,we've established that fairly rapidly people began to find these things. Once they'd started to find them,why did we keep needing to find more of them.I mean we could say "Yes,okay,Dirac,you're right",but I mean it must be very time consuming,very energy consuming,very money consuming.

Rolf Landau : Well ,I mean,the question why we really look after antimatter now,and to try to understand it came really, would say the key point was in 1967,there was Andrei Zakarov who tried to understand the creation of our universe,and the only way he could sort of think of the big-bang creating all of the matter was to assume that the big bang started with a state of energy,which then converted in equal amounts of matter and antimatter,and of course then big question is,since the universe at the beginning is very small,and the matter and the antimatter particles are still in contact and can annihilate,why was there anything left?

[And why was it matter tilted to the left? There must have been an imbalance or imperfection in that primordial atom in order for our universe to exist -LB]

Quentin Cooper : So hang on doesn't that make the universe an anomaly in someone's theory?

Rolf Landau :  Absolutely,the universe (John chuckles) should not be filled with matter,but with radiation,the end product of these annihilations,and so the simple question is,why did one take away one did not give zero,but a small number,and that's all the matter which is left that's us,the stars,the universe,and this is the question,why we try to understand this tiny obvious asymmetry between matter and antimatter,and that is what motivates our research.

[Note that this is more a philosophical problem,rather than anything which produces "useful" gadgets,it is nevertheless a profound problem deserving an answer. The rather shallow "what will I get out of it?" view would cut off this research and leave us none the wiser. Wisdom is what we get out of it,and you can't put a price on that -LB]

John Fry : I think one has to say that we mean by small here....

Quentin Cooper : I think you have to say what Rolf means by "simple" and "obvious" as well!

John Fry : ...well,well maybe that as well,but by "small" we mean one part in one thousand billion,all the rest is annihilated,and so this colossal universe that you see with billions and billions of galaxies and stars and so on,that is the product of one part in a billion of all the energy that was initially created,that's our......

Quentin Cooper :  How do you get a figure like that?

Rolf Landau : What we do...

John Fry : ...now then,now then now then [Scientists are not know for their Jimmy Saville impersonations,this was a particularly bad one.Maybe Rolf will say "Can yer till wot it iz yit?" next -LB] that's going on to advanced (laughter) questions! What you do is to count the number of photons,and the number of neutrinos and from the theory you say that originally they would be about equal to the constituents that we see in matter the protons and the electrons,and so we can count the number of protons in the stars,we can count the number of stars,we can count separately the numbers of photons and neutrinos,and we find this very very big factor of about a thousand billion.

Quentin Cooper : Rolf I take it this is why you want to go about creating antimatter in the lab is to try and get more insights into these anomalies?

Rolf Landau : Yes,I would say..I consider it as a puzzle and everybody tries to get a little piece of the puzzle and get that right and then put it together with say John's piece of puzzle,you know, and we try to put the picture.
So I just want to add one thing,I mean it turned out that,and the study of these tiny asymmetries,which are sometimes not that tiny,you know,is very important for our life,obviously. Life seems to be dependent on tiny asymmetries,for example all the proteins in our body are left handed,

[Told you so!!! Maybe God is a southpaw??!-LB]

even though nature produced them right and let handed,so there is something behind these asymmetries in the laws of nature,and that motivates also our research here,but....

Quentin Cooper : So having started  with this mirror,we've now put a little bit of a curve into our mirror? [That's it! -LB] It's a slightly distorting mirror?

Rolf Landau : Exactly,exactly,there seems to be a slight distortion and we are trying to find out what causes it,and so now coming to the experiment,I mean what we are trying to do is to produce a tiny part of this hypothetical anti universe (http://www.newscientist.com/nl/1007/gambling.html)
which is made mainly of anti-hydrogen,so we are producing anti-hydrogen atoms at CERN,using this anti-proton decelerator.

Quentin Cooper :  And explain why you want to decelerate your anti-protons?

Rolf Landau :  Well,basically,to produce antimatter it has to be very,very hot,now so it's about 100 million,about a million times hotter than the inside of the Sun,so this we cannot sort of simply heat a piece of metal or so to that temperature,what we do is accelerate particles,to very high energies,and then let them collide and these collisions you produce enormously high energy densities,high temperatures if you want,and there spontaneously you produce anti protons.Now when they are that hot you cannot recombine them with positrons in order to build an atom,you have to cool them down,and this AD machine,is a device that allows you to bring the speed from the speed of light,when they are produced,down to a tenth of the speed of light,and from then on our experiment takes over,captures them,in so-called traps,and brings them down to almost absolute zero in temperature or in speed.
And then...

Quentin Cooper : Any joy yet? Have you made any anti-hydrogen?

Rolf Landau :  Not yet,but we are close,we have the accumulator trapped and the anti-protons brought down to very deep temperatures,and we have done the same with the positrons,and we are just working on,is to get the two together and so,in a few weeks maybe have the the firs anti-hydrogen atoms.

Quentin Cooper :  Because one thing we should stress here is of course,although we've talked about the first antimatter,in terms of antiparticles being discovered,you know,way way back in  the 1930s,in actual...in terms of making actual atoms of antimatter that's relatively recent isn't it? I mean I think you were the person who adjudicated on the first atoms?

Rolf Landau :  Yes that was about 4 years ago,and that was a little experiment at (indistinct) also at CERN,which sort of did a little test if that's going to work,but they used a different method,it was at the speed of light that these atoms were produced and very few of them,and so now we use a different way to do it,and that is more promising for the study of them.

Quentin Cooper : And Rolf the idea is with your anti-hydrogen,you going to compare anti-hydrogen to hydrogen and look for discrepancies and similarities?

Rolf Landau : That's right,I mean one piece of the puzzle would be,is there any difference of this antimatter universe to our universe,and so we try to look at the fingerprint of these atoms,the energy spectrum,and see if they are different,and we try to do that with a precision,which is quite...very high,it's about one part in 1015,that's about in simple terms,I mean if I take John as weighing a hundred kilos,sorry John I know you work out now (John laughs)....

John Fry : I'm a lot less than a hundred kilos!

Quentin Cooper : keep going.

Rolf Landau : Okay I believe you! And it's like a grain of dust,which you can just see on the microscope,in addition to his normal weight you know,that's about 10-15,so we are trying to do a comparison of these two atoms to that precision.

Quentin Cooper : Now John,when you're not working out,what you are trying to work at is about is on..you're looking at antiparticles,and you have already found the sort of evidence that Rolf's looking for on a particle scale of asymmetries haven't you?

John Fry :Yes we saw a difference in the rate at which a kaon and it's antiparticle the anti-kaon decayed.

Quentin Cooper :  You'd better very briefly say what a kaon is.

John Fry : Well a kaon is one of the particles that you can produce,it's a little bit like proton and anti-proton,there's a whole family [Ref Focus Mar94 p56 {Particle zoo}] of different particles and the kaon is one of these. This is a neutral particle....

Quentin Cooper :  Right.

John Fry : ...and that's very important,because that means we can look at the kaon and the anti-kaon decaying  into the same products,and they should both give the same [see whatdoes.html@nbci] if the matter and the antimatter universe behave in the same way,and they don't.Now this was something that's been known for many years and what we did was to confirm that in a very elegant and very high statistics way,so that wasn't anything new,it was just very pretty,but what we went on to do,was to look and ask the question,"supposing the universe ran backwards?" and you imagine time going backwards,would it look the same? Would it behave the same? And so we took our kaon and our anti-kaon and  in a very very sophisticated experiment we watched the kaon turn into and anti-kaon and we measured the likelihood of this happening,and then we did a slightly different experiment where we started with the anti-kaon,and we measured the likelihood of that turning into a kaon.So if you like we're looking at one process and then the second process is the one we would get if we were able to run our laboratory and turn time backwards.
So within the laboratory,we're doing an experiment that measures "Do things look the same when you run time backwards?" and we found they don't,so where's.....?

Quentin Cooper : Leaving aside the business of how you turn time backwards or even simulate turning time backwards,what does this usefully tell us? Is this giving us more insights into the matter antimatter discrepancies in the universe as a whole?

John Fry : Yes it is,because what we believe is that if we turned the universe into an anti-universe and we ran time backwards that everything should behave absolutely identical,this is something that Rolf's experiment is related to,and so one of the questions that we wanted to ask in our laboratory experiments using kaons and anti-kaons was could we do that experiment? And indeed we did that experiment and at the level of precision that we were working we found that changing the particle into the antiparticle and then running time backwards,gave us exactly the same thing.

Quentin Cooper : Now,it's a slightly naive question John,but there's no possibility that the discrepancy is because your experiment is in our matter universe and if you were conducting all these experiments in an antimatter universe everything would be the opposite and thus the balance would be restored?

John Fry :  No,there isn't any possibility of that,because when we are producing these particles we're producing them in a vacuum,and so we can tell very clearly that we're dealing with matter,or that we're dealing with antimatter,we can track the individual particles,we can be absolutely certain that we know the identity of the particular particle,so we know the identity of the particle when we create it and we know it's identity when it self destructs,you know radioactive decay type thing,and so we're absolutely certain that what we've done is a fair statement of how matter and how antimatter behaves,and how time running forwards and time running backwards would behave.

Quentin Cooper :  Right fine,I'll just have to check on that,Rolf apart from helping explain the universe and the fundamental laws of physics which is quite a lot,are there any other practical uses to antimatter,I think John's already talked about this PET system.Anything else?

Rolf Landau : Well,let me just make a comment on John, I mean the risk of time running backwards is that you have to give your salary back at the beginning of the month! (laughter) Okay,anyway,apart from that,well John has mentioned already that positron emission tomography is a daily use of,in medical diagnostics of antimatter.
So you reconstruct the place where these positrons decay in your brain or whatever,and they have been brought there by some sugar or so,but as for anti-proton technology,anti-hydrogen technology,that's of course just in its infancy,I mean you have to say that anti-protons are really brilliant batteries.Their energy density is about 100 billion times higher than those of ordinary batteries,but the problem here is all the energy you have to first put in again and that's not a very efficient way to do it.So also antimatter must be kept away from ordinary matter,so otherwise they annihilate.
[Remember that when calculating the risk of a PET scan against using a mobile phone -LB]

So,but having said that,there are several groups which try to investigate the use for producing medical isotopes or even for cancer treatment.

Quentin Cooper :   Okay well thank you very much Rolf Landau and John Fry thanks,I'm afraid since there hasn't been a flux of strangely behaving kaons we are out of time!

So I'm going to move onto another area of strange asymmetries,differing conceptions of time,powerful forces and sometimes of opposites attracting and destroying each other.

[I'm saying nothing! -LB]

Sex,or to be more precise similarities and differences in male and female sexual behaviour.Well it's hard to turn "Men are from Mars,Women are from Cadbury's" into a fully fledge scientific hypothesis,other theories are more readily testable.

"Woman like long necked bottles,
and a big head on her beer,
I don't like to talk about my women,
but I hold that woman dear."

"Women like a a long necked bottle and a big head on their beer",I'm not sure that Captain Beefheart's observations on female alcoholic beverage and container preferences are in fact borne out by the the data,but then more widespread male views of female sexual behaviour are now also shown to conflict with the facts,views particularly on promiscuity.
The received wisdom banged home [That's one way to put it -LB] by centuries of fiction and phrase-mongering,is that whilst jack-the-lad,play-the-field blokes want to sow their wild oats more widely than a badly organised GM trial,

[LOL Quent slays me! -LB]

females the odd loose woman or maneater aside are much more naturally monogamous, "Except", says,Sheffield University's Professor Tim Birkhead,author of the just published Promiscuity, "that's not the case","What's more", says Dr Ann McGurran of St Andrews,"it's not even the case with guppies".
 Ann and Tim I should just make it clear about yourself,now your both sort of in the field of evolutionary biology aren't you,come behavioural ecology,which sort of blurs together?

Ann McGurran : That's right.Yes.

Quentin Cooper :  And Tim,if this idea that men are naturally promiscuous and women are naturally monogamous is wrong - and we'll get onto the evidence I hope in due course - why has it become so widely accepted?

Tim Birkhead : I think the reason why we have this myth of the monogamous female,we can go back and blame Darwin [Oh that will suit all the believers! -LB].Darwin wrote that females were monogamous,across all animal species,when he published his great book on sexual selection,and when I read this,I found it hard to believe.
Darwin knew so much about everything,I just couldn't believe he was that naive,so I set about trying to find evidence that Darwin knew animal,female animals to be promiscuous,and I found plenty.So the question then became "Why didn't he write about it?",and I think there were three reasons.
First of all with queen Victoria looking over your shoulder you really wouldn't want to talk about promiscuity.
Secondly his granddad Erasmus,was a bit promiscuous and that would have been bit embarrassing for Darwin,but thirdly an most importantly,was his daughter,Henrietta.
Poor old Henrietta,unmarried,initially was regarded as a closeted Victorian matriarch and she helped Darwin edit his book on sexual selection,and she was a bit of a prude,and anything she didn't like she just slashed out [Because she was a woman or because she was a prude? Scientific evidence was corrupted -LB],and I think we can get a feel for what Henrietta was like,because in later life she started campaign,almost single handedly,to have the stinkhorn fungus,who's scientific name phallus impudicus at once identifies and describes it,she tried to have this fungus banned,from the British countryside.

[What a dirty mind she must have had!! -LB]

Quentin Cooper : What a wonderful story,so Anne this seems to be a case of Victorian values permeating into contemporary morality?

Ann McGurran : That's right but of course,what biologists have recently recognised is that there's a huge amount of variance in reproductive success between males and females,and that females can in fact maximise their reproductive success by being slightly more promiscuous than Darwin originally recognised.

Quentin Cooper : Well you say people have recognised this,I mean Tim when did people begin to actually say,to sort of move away from Darwin and actually start challenging this data?

Tim Birkhead : Things started to change in about late 1960s early 1970s when people recognised that some females notably in yellow dung flies

[What were they doing looking at dung? Euuuugh! -LB]

would actually mate with more than one male,but even then,the emphasis was largely on males,it was kind of considered that females were passive or reluctant participants in this in sex like this,but the important discovery made at that time was that if females do mate with more than one male,you get what's called "sperm competition",the competition between those different male's sperm to fertilise that female's eggs.
It was then another 15-20 years before people started to focus on the female perspective and ask themselves "Well,why are females promiscuous?".

Quentin Cooper : So just tell me a bit more about "sperm competition",here,so what is going... what is sperm competition and how does one win?

[There are many answers to that,all of them too lurid to reproduce here within a Victorian morality framework! -LB]

Tim Birkhead :  Okay,sperm competition,is simply what happens when females mate with more than one male [A sort of spermatozoic natural selection?-LB]. If you think about it,the male that actually wins the competition fertilises the female's eggs it's going to be his genes that get into subsequent generations,and the way males win in sperm competition is mainly through inseminating more sperm or through having better quality sperm,faster moving sperm or being able to place their sperm in a position that gives them some kind of fertilisation advantage?

Quentin Cooper :  Right,so just to be clear about this,we're not simply talking metaphorically here about saying when males are in competition,their sperm is in competition,this a literal, you know head to tail race,between sperms of different males,inside the same female in some instances?

Tim Birkhead : Absolutely,and it can take a multitude of different forms,in different species.

Quentin Cooper : Ann McGurran,d'you think another factor that the whole reason science research has only begun to orient this way now,is that it was previously male dominated [see women.html@nbci] and some of these thoughts were unthinkable to male scientists?

Ann McGurran : I think that's possibly true,but then on the other hand,a lot of men have been very astute in recognising female choice.I mean we talked a little bit about Darwin,and although he didn't recognise the extent of multiple mating,in fact he thought monogamy was the norm,it was in fact him who identified female choice,as an important driving force in sexual selection,so although feminists and female biologists have been pivotal I suppose in bringing these ideas to the fore,I think it would be wrong to say that males have not been important in the field as well.

[Sex in the field,whatever will science think of next? -LB]

Quentin Cooper : Good,I'm glad males and females together is still figuring in the equation somewhere.Now you've been looking at guppies...

Ann McGurran : That's correct yes.

Quentin Cooper : ...and what the evolutionary advantages might be for females in having multiple partners.Now first of all why guppies?

Ann McGurran :  Well,the very pragmatic reason is they are nice and easy to keep,I think anyone who's kept guppies at home in the aquarium will realise that.The more important scientific reason is that they are a very good model species for looking at evolution,in the wild,and guppies are found naturally in Trinidad,and we go to Trinidad and look at different populations,and see how rapidly they evolve in response to different to different cues.

Quentin Cooper :  I think that can boil down to "guppy's are found in Trinidad" as a very good reason to research them myself.
[I'd volunteer! -LB]
But that's fine...

Ann McGurran :  Well,that's a nice reason also!

Quentin Cooper : So what did you do,and what did you find?

Ann McGurran :  Well,I should say first of all that we,that's John Evans and myself,a colleague that worked in this experiment,and what we started off with was by looking at female reproductive behaviour. Now male guppies are absolutely classically promiscuous.If you go to the wild you'll see that male guppies try to mate with females once every minute.
[And God made me a human being,what a tight misery he is! -LB]
Females are much more discerning,and they're interested courtship,fairly infrequently.
[That's what I've found,but then I never dated a fish! -LB]
In fact they're only interested either as virgins or just after they've given birth,and so our starting observation was that although females are very particular,about when they mate, when they are in the time of mating,of when they feel like mating they will actually solicit courtship from several different males,and this was a curious observation,because we also know that courtship for females is costly,they run the risk of getting sexually transmitted diseases,they lose foraging opportunities,they are exposed to predation.
[I'd never eat anyone on a first date! -LB]
So what we really wanted to do was to start off by finding why the females are doing this,what were the potential advantages.....

Quentin Cooper :  And?

Ann McGurran :  ...and...so we set an experiment up in St Andrews,and what we did was to have virgin females,and we had to use virgin females because of sperm storage,and we gave them a choice,or not giving them a choice,but putting them in two different situations.
In the first situation they met the same male,4 days for 4 hours,and the second situation,they had different males every day for 4 hours,so the same male repeatedly or different males, and then we looked to see how quickly they produced offspring,how many babies they had,and what the life skills of those babies were,and I should say the life skills is important because as anyone who has  kept guppies at home will know,guppies are very cannibalistic.

[Cannibalism may not appear to make any sense in natural selection at first sight,but if one studies non-linear systems,one can see how it makes sense. Killing some offspring and using them as a food source aids survival.Killing of those which maybe carrying the sperm of another male,kills of the potential of that male's (and possibly female's) genes passing to the next generation.So there is a reason why cannibalism can exist in natural selection -LB]

So in order to be successful and to survive,it's very important that new born guppies are able to avoid cannibalism and other potential predators,and so the answer that we found was actually quite dramatic.The females had had...who were mated by several different males produced more offspring,they produced them more quickly,and the babies as we had hoped for,were actually much better at avoiding predators,and much better at schooling behaviour.

[It's always best to behave in school in case you get a chalk duster chucked at your head! -LB]

So this seemed to be a very dramatic demonstration of the benefits of multiple mating,in this particular species.

Quentin Cooper : So Tim Birkhead,this is very strong evidence pro-promiscuity?

Tim Birkhead : Yep,I mean,if females behave in a promiscuous there's got to be some benefit for them doing that,and Ann's study provides some nice answers for why females are promiscuous.

Quentin Cooper : Do we also need to understand more about how they are? Because obviously to a lot of us it seems a ridiculous idea,that you would have thought whoever you mated with,if you were a female,you mate with somebody,then that's their sperm,and that's it,your stuck with that,it doesn't matter about mating with other people? We need to actually rethink about the biological side?

Tim Birkhead :  Yeah,that's what we're studying at the moment,we're trying to understand the mechanisms by which particular sperm,fertilised particular eggs,and one of the really fascinating aspects about this is something that we call "cryptic female choice",

[They choose the guy who's best at crossword puzzles? -LB]

and that is that the female mates with several males,she stores the sperm from those different males in a special sperm storage structure,and then in some cases,we know that females can differentially use the sperm of those males that she prefers,

[Ah so a female guppy is exercising "preference" something animals don't have according to non-scientific models? -LB]

and so the female is choosing which male's sperm are going to fertilise her eggs,and that's mind-boggling,I mean that is just absolutely remarkable.

Quentin Cooper :  And what does that...? I mean obviously we're talking about individual species here.We're talking about female promiscuity as a variable if you like,rather than a constant,but how widespread is it?

Tim Birkhead :  Cryptic female choice? We don't really know how widespread it is.I mean I think it's likely to be restricted to those cases where females can't make a good choice of partner before they mate with them [Ah so that's what happened! -LB],so species where females can't discriminate very well between males,species where females might be forcibly mated by males,as happens in several ducks and chickens,I think that those are the most likely situations in which cryptic female choice might occur.But of course it could still be a kind of last opportunity for choice,even in species where the females can choose their partner.

Quentin Cooper :  And of course the $64,000 question that you both know is coming - To what extent does it or doesn't it apply to our own dear species,humankind?

Tim Birkhead :  Well,of course we have no idea,and it would be very difficult to study this, however....
[I could volunteer to go to Trinidad and swim around with some test cases? -LB]

Quentin Cooper :   You have an inkling I bet?

Tim Birkhead : (laughter) ....well, think it's not impossible,given that we've found it in a number of other organisms,it's quite feasible,that it could also occur in humans,and if it did,and if we could understand it,then it would revolutionise fertility an assisted reproduction treatment.

Quentin Cooper :  Ann McGurran,I know guppies are your area rather than humans,but do you have any thoughts on this?

Ann McGurran : I think Tim is very right and very correct in his speculation,as he said it's actually very difficult to prove the mechanism of cryptic female choice,and I think we have to give you the very unsatisfactory answer that there's still an awful lot to learn about this subject,but there's certainly enough to keep us all busy for an awful long time to come.

Quentin Cooper :  But Tim,finally,I mean you do accept there's an interesting possible,you know, discrepancy here between what's socially acceptable and what's biologically desirable?

[That's very interesting,our morality is actuality counter to what has survival value! -LB]

Tim Birkhead : It depends what you think is socially acceptable?!

[Nice answer! -LB] (Ann giggles)

Quentin Cooper : Well,by convention.

Tim Birkhead :  I'm not really clear what you mean!

Quentin Cooper :  Er,well I may have to leave on a point of horrible ambiguity then in that case! I was sort of trying to refer to...I'll have to answer my own question.
That obviously,if we find that there  biological advantages in promiscuity,but however the morality of our times is set against it and perceives that women who sleep around are dodgy,then you might have problems,but I'm afraid we must leave it there.
Thanks to Ann Magurran,Professor of Evolutionary Biology at St Andrew's University,and Tim Birkhead,Professor of Behavioural Ecology at Sheffield.

Next week,assuming my tattered sense of masculinity can leap through until then,we'll be looking at solitons.
[Solitons are amazing -LB]
Not an antimatter particle,but strange solitary,only just beginning to be understood waves,which turn out to be widespread phenomenon,affecting telecommunications,our bloodstreams,possibly even the formation of our solar system.Solitons -the only game in town
[Oh how awful,that's nearly as bad as "it's official -it's a fish oil" another one of Quent's gems -LB]
on next week's Material World.

23/10/2000