Sex can become purely recreational - and reproduction can become purely clinical, the product of in-vitro fertilisation (IVF). Already more than half a million people - the oldest now 21 - owe their origins to a petri dish rather than parental union, and like the first swallows they are the harbingers of a new summer. Modern reproductive technology is leading us headlong into a major social revolution. How will we cope? In fact, psychologically the separation of sex from reproduction needs no adjustment. It is nothing new. The human psyche has always been able to divorce the two, any link seeming so tenuous that our ancestors had more trouble connecting than separating them. We can easily see why. In cultures lacking contraception, an average of about seven children is produced from about 3,500 acts of intercourse - about one in 500. Little wonder that to many of our ancestors a relationship between the two seemed absurd.
Any claim that humans are the only species for whom sex has a recreational role is biological nonsense. Lions, for example, have sex 3,000 times to produce each lion cub and our two nearest relatives, chimpanzees and bonobos - the latter in particular - are forever having sex. For them, intercourse is virtually a greeting - a handshake. Clearly, natural selection weakened the link between sex and reproduction long before technology came on the scene. All that modern technology has found the potential to do is sever the link completely.
The future separation of sex from reproduction will be the culmination of a drive for foolproof contraception that has gained increasing momentum during the past century. Even this drive, though, has its roots embedded in our biological past. Life has always been a roller-coaster of good times and bad. The effective system of family planning that natural selection produced for our primate ancestors was to intersperse periods of stress- induced infertility during the hard times with periods of high fertility during the good times.
Until the 20th century, stress was most women's only contraceptive - as, to some extent, it was men's. Nowadays, couples prefer to rely on biotechnology rather than stress - but do so at a price. Current contraceptive methods are either decidedly "unfriendly", inefficient or a danger to the user's health. Part of the problem for contraception technology has always been the primary need for users to retain their fertility so that they can reproduce later if they wish. Modern reproductive technology, though, could make this requirement redundant, thus paving the way for a new approach to contraception and family planning - the BlockBank system.
By the middle of the 21st century, men and women will bank (ie cryopreserve or freeze-store) their sperm or eggs at some time early in life and have their tubes (vasa deferentia or oviducts) cut, tied or otherwise blocked. The avoidance of unwanted pregnancies and unwanted abortions - and unwanted child support payments - will be guaranteed. Such people will give themselves total freedom to have a family at any time they wish - and increasingly with almost anybody they wish.
To have a baby, all a person needs to do is arrange to have their gametes united with those of the person of their choice, via IVF. The age-old search for a gamete partner (the genetic other parent of one's next child) would take on a radical new meaning. Imagine the options. Should a person reproduce with somebody he or she knows - a joint venture? Or should they go it alone and purchase the gametes of somebody famous - or even dead?
Should they reproduce with somebody the same sex as themselves - because technology will soon allow egg to fertilise egg and sperm to fertilise sperm - or the opposite sex? If they are female, should they gestate the child themselves or should they commission a surrogate or hire an artificial womb? And when should they have their first child - in their teens, or in their twenties, thirties, forties, fifties, or even sixties? Advertised on the Internet and browsable from reproduction restaurants, people's reproductive choices will be almost endless.
Of course, it is easy to imagine problems with the BlockBank system - but are they real, or do they simply stem from a reflex distrust of anything new? For example, as with any banking system, men and women might not trust the gamete banks with their sperm and eggs. What if people's gametes get mixed up, or cannot be traced when needed? In theory, of course, thanks to DNA fingerprinting, bar-code labelling and computer technology there should be little danger of such mishaps - but experiences with monetary banks do not inspire total confidence. Reassurances will be essential - such as DNA testing to confirm genetic parenthood before embryos are placed in the gestation-mother's womb.
What if a person falls behind in the payment of his or her gamete-storage premiums, or if the storage company goes out of business? Payment protection policies will undoubtedly be needed, as will government underwriting of any private storage companies. What if a person's gametes are really lost? We can relax. No such calamities are terminal; there is a safe fallback. After all, both men and women continue to produce gametes even after their tubes are blocked - it's just that they never find their way to a place where fertilisation can occur. So if a person's adolescent deposit into their gamete bank account does happen to be lost or destroyed, further deposits can be made later in life.
The BlockBank scheme won't immediately appeal to men and women who dislike medical invasion, no matter how trivial. Tube-blocking currently requires surgery, albeit minor. In addition, women would need to go through induced ovulation and egg-harvesting when initially banking eggs. Finally, the fertilised egg must be inserted direct into the woman's womb - another uncomfortable procedure. So, will the men and women of the future be prepared to put themselves through such discomfort in the name of contraception and family planning? The indications are that many may. After all, in the pursuit of health, women have for years been prepared to suffer the discomfort of cervical smear tests.
In the pursuit of family planning, they have been prepared to tolerate the discomfort of being fitted with intrauterine devices (IUDs) - and later having them removed. They have even been prepared to risk their lives with back-street abortionists. Finally, in the pursuit of contraception, both men and women have already been prepared to have their tubes blocked - and in surprising numbers. In Britain 15 per cent of women of childbearing age and 16 per cent of their partners are already sterilised, with most men having vasectomies in their thirties. In Asia, half of all couples who need contraception choose sterilisation of one partner; in India this rises to three-quarters.
It seems highly likely, then, that if the BlockBank scheme were on offer now a significant number of people would opt to use it in their quest for foolproof and risk-free control over their reproductive lives. They would tolerate three or four moments of discomfort in their lifetimes for the freedom to reproduce when and with whom they wanted, with no risk of accident or misfortune. And in the future, with all elements in the scheme becoming increasingly user-friendly, reliable and socially acceptable, BlockBanking's future seems assured; it is destined to become the favoured form of family planning for the majority of people.
BlockBanking is most advantageous when performed early in a person's life - such as soon after puberty. Not only does the blocking provide contraceptive protection at a most vulnerable age but also the banking of eggs and sperm during adolescence is of extra value. First, it provides early insurance against accident and disease - ovarian or testicular cancer for example - later in life, which could threaten a person's reproduction. Secondly, sperm and eggs produced while young perform much better in IVF than those produced when older. And, for women in particular, gametes from a young person are much less likely to create children with genetic disabilities, such as Down's syndrome.
The chances are, therefore, that when the scheme finally gains public confidence, many a parent will urge their post-pubescent child to join as soon as possible. Dastardly though such parental coercion may seem at first sight, it is a much more responsible and caring act than, say, the acts of circumcision that parents in many cultures, including our own, have for centuries happily inflicted on unwitting sons and daughters.
Who would pay for the BlockBank scheme, given the undoubted costs of blocking, banking and IVF? Is this just one more sign of a future society in which only the rich can afford the advantages that technology will offer? Maybe - but maybe not. Governments already spend large sums of money on free contraception and then on the medical and social problems that arise when contraception is neglected, or fails. Subsidising the BlockBanking scheme to make it available to as wide a cross-section of people as possible may well be cost--effective.
And what of relationships? What does the future hold for the ancient magic of procreation and the raising of children? Life - particularly family life - is bound to change in the future but nothing will stop people from experiencing sexual and parental emotions. These are ingrained - genetically programmed into body chemistry and psyche by millennia of natural selection. Nevertheless, when set against a future social backdrop of ever more numerous lone-parent and blended families and a future medical backdrop of increasing supremacy over sexually transmitted diseases, the separation of sex from reproduction will undoubtedly release many biological brakes.
More dramatically and lastingly than after the contraceptive revolution of the Sixties, women in particular will be freed from the constraints of their gender. Inevitably, relationships will become shorter-lived and promiscuity will increase; it will become the norm for a person to have children with more than one partner. Half-siblings will abound and increasingly a person will think of his or her family as theirs rather than as theirs and a partner's.
But, of course, people will still experience the whole range of life's emotions. They will still fall in and out of love and still dote on - and argue with - their children and parents. Divorcing sex from reproduction is destined to create a social revolution as great as any humankind has ever seen - but it cannot kill the ancient urges that made us human in the first place.
The author's `Sex in the Future: Ancient Urges meet Future Technology', is published by Macmillan, price pounds 12.99Reuse content