The first part of the above title was an arresting headline on today’s ScienceDaily website. With such a free offering available, I couldn’t resist. Then, because of the route that that my morning walk took me along I subsequently added the second question.
To start with the first, a fact of life among both apes and mankind (both of which have had a common predecessor) is that it is females who choose when to have sex — and with whom — and not males. And, perhaps usefully for such a characteristic instinct to continue to exist, men are usually willing and don’t often turn down the opportunity.
Why this is so and, indeed, why is there sex at all, when the overwhelming majority of creatures — bacteria — are sexless has long puzzled biologists. As far as bacteria are concerned, these simple creatures with only one cell as their total body have sex by simply dividing when the time is right. This is always, and as soon as, when all its cellular systems are fully nourished and up to scratch. If there is the likelihood of yet more surplus food being available in the outside world then the bacterium will have sex with itself by dividing, thus producing two cells == itself and another — for the next generation.
This is a very efficient way of reproducing — namely, 100% — because every single bacterium can produce at least one other cell — which we can call a daughter cell or a son cell — when the time is ripe for the next generation. There is no wastage, as it were.
But with sexual generation in creatures with more than cell — multicellular creatures such as ourselves — it is still the case that only one offspring is usually produced by a mother. But this time it can be of one of two sexes. But it’s only the daughter who can, in due course, give birth again in the next generation. For the contunuity of the species the son is thus no use (apart from a brief, occasional sexual activitiy). Nature seems to have developed a very wasteful procedure of only 50% efficiency. This seems a step backwards in reproduction efficiency. How has it been possible that nature has evolved this system?
Biologists have long puzzled over this and have come to the conclusion that sexual reproduction must confer some more than compensatory benefit for the 50% efficiency. And they came to the conclusion that this benefit is a health (or genetic) benefit which non-sexual reproduction of the bacterial variety mkight not confer. Perhaps the immune systems of multicellular creatures are stronger than those monocellular creatures.
Alongside this growing hypothesis is an observed fact among humans that females, if at all possibe, always choose males who are healthier — that is, genetically superior — to the average, given the circumstances aroubd her at the time. In the case of both apes and humans, this generally means females choosing males who are intelligent more than any other quality — and the more intelligent the better. After all, males who are intelligent can often compensate for any genetic weakness they may have — such as poor eyesight or weak knees. In practical terms of modern life this usually means that women always tend to choose upwards in social status when choosing a male as a future partner and fellow parent. Such a male is more likely to be able to offer a good economic future for her and her family.
But although this choosing-upwards tendency by women has been observed many times in retrospective surveys, the underlying hypothesis has never been proved. The higher social classes have far superior health than the lower ones but this is not a scinetific observation becuase upper class people are richer and can afford better food and better doctors than the poor can. In humans, it never will be proved conclusively because scientists can never carry out an experiment comparing sexual females with non-sexual females but who yet able to have children!
There are, in fact, very few multicellular species where the alternatives can co-exist. Ideally, an experimental biologist would like a species which not only can reproduce in one way or the other but also farily rapidly, too, so that the epxeriment can run for many generations.
Such a one is the Tribolium flour beetle and was chosen by Prof Matt Gage of the University of East Anglia to fairly represnt all multi-cellular creatures (at least among rational people) for an experiment to go on as long as it might take. His research team divided a large number of beetles into ten populations and kept them separate. They ranged from a highly competitive population in which 10 females beetles could choose among 90 male beetles down in stages to one in which the males hardly had to be competitive at all — where they were 10 males and 90 females and then, finally, in a population in which there were no males at all and the females could only reproduce non-seexually.
In nine of the mixed-sex populations only the beetles which were the product of sexual reproduction were chosen to provide the stock for the next generation. The result was hat the no-sex population became less and less fertile from one generation to the next and became totally extinct by the 10th generation. In the case of the nine surviving populations the experiment continued for 50 generations but, on exposure to various diseases the strengths of their immun systems varied dkirectly with the sexually competitive level. Overall, competition between males more than compensates for the theoretical loss of efficiency in passing on genes.
This is the most definitive experiment yet — and was thus published by Nature journal — to prove that although non-sexual reproduction might enable a species to survive when in unusual circumstances it could only survive over the long term by sexual reproduction. Choosing-upwards by females, simulated in Prof Cae’s by gradated populations thus guantees maximum possible protection against disease.
All this is why, in evey human society, in every nation-state or in any regional culture there will always be rank ordering, or different social status levels. In modern-day terms, there’ll always be the rich and the poor whether the economy as a whole is an advanced one or an undeveloped one. Right-wing poliical parties understand this because they know they are usually the products of high status families and exclsuive schools, but left-wing parties — at least in most countries where more than one party takes part in choosing a government and where the party has existed for more than a generation or two — cannot yet accept this fact of life — though often their leaders will believe this privately because they themselves are the products of families of higher social standing than the people they represent.
When left-wing parties accept this fact of human nature — and of the necessity of rank-ordering, too — which enable women to choose their partners for the sake of healthier children, then we might see more sensible policies than they;re usually given to, or at least policies which genuinely help the poor. And, furthermore, when this fact is widely understood by the electorate, perhaps we can then start to re-jig our method of choosing government and get rid of the present ridiculous — and very expensive — knockabouts that take place at election times.