Reproduction by combining genes from two animals increases variation. Variation and hence adaptation to changing encounters, can progress at a faster rate. We look at this in detail in the variation, unpredictability and mathematics topic.
Early organisms can reproduce by division but variation can be greatly extended if two separate organisms of the same species combine in some way. Packets of DNA evolved within each organism alongside ways of combining the packets so that together they become the next generation of the organism. One way of doing this required one of the organisms, after division, to turn its new self into a reduced version of itself and hang onto it as an egg. Over time it evolved the ability to produce many eggs. The second DNA packet would need to enter the egg (s) and together they would form the new animal. We call this fertilisation and the two types of animal required by each natural species as female and male.
The big challenge happened when animals took to the land. The watery environment had to go with them. The male had to develop an external organ to insert into a special hole developed in the female. Then mammals evolved. They kept the egg(s) in a placenta and directly fed them from their own body. A biological adult is an animal developed enough to take part in reproduction. Some animals, including ourselves, have also created social adulthood which is also predicated on breeding actions.
In order for two animals to combine to produce the next generation, models had to be evolved that overrode the basic intimacy model busy defending intimate space. Let us look at the sexual models required to break through the intimate model. As they approach, many male web spiders have to ‘play’ on the female’s web in very precise ways in order to mate. If they get it wrong they are eaten. In some species the females get the best of both worlds by simply delaying eating the male until it has finished. By way of balance, Sherazde tells stories to avoid the death that follows from mating with the Sultan. In all animals we can see courting and mating modeling being played out. It is fundamentally designed so that the individual animals do not injure or kill each other in defence of their body and do not mistake each other as food.
Courting and mating modeling can include the involvement of other registers to allow a choice to be made between potential mates. However, the demands of a ‘choice’ model change the terms of existence as it is now not just about living long enough to breed but living long enough to be chosen to breed. Choice modeling can even change the physical nature of a gender within a species so much that it compromises the ability of the animals involved to stay alive. How useful in surviving in nature is a peacock’s tail and why do peahens not have them? It is usually the females of a species who are the choosers and the males who are the chosen. This can only make biological sense if there is competition. The competition can create fighting between males. The fighting can itself be used as a register with the female choosing the winner. For ‘settlement humans’ in particular, common stories include courting and mating where the chosen male wins ‘fights’ with other males.
The sexual model also uses high registers of the beneficial emotion of satisfaction/ happy. Included in its triggers are specialised perceptual and associated biochemical registers that directly relate to penetration into the body during the reproductive act itself. The basic intimacy model from nurture is also involved and the development of this within the sexual act makes the term ‘making love’ meaningful.
The beneficial emotion is strongly involved in sexuality and is present from birth. In my job a common referral were children, usually in nurseries, masturbating. We call the parts of the body involved the erogenous zones. Primarily they begin in an area around the sexual organs that can be stimulated through touch and, after puberty, continue through to ‘penetration touch’ and orgasm. Other animals must (philosophically) have species appropriate similar experience. Try tickling your neutered female pet cat on its back at the point that the tail emerges. It might keep still for about the same length of time that the mating male cat would take and then turn round to bite and scratch, just as it would the male cat.
Within sex the beneficial emotion is therefore fundamental in two ways, firstly as sexual touch and secondly through intimacy derived from nurture. This is evident when we consider the possible drift into ‘baby talk’ between lovers where the involvement of nurture modeling expresses itself in a different form.
In summary, every animal that has intimate space intrusion and physical touch with either a mate (sex ) or with offspring (nurture) needs an overriding emotionally based model made up of perceptual modeling and biochemical registers. Both the carer(s) and the young have to have models for beneficial intimacy. The only candidate emotion is satisfied /happy, the beneficial emotion. This has to sufficiently dominate over unpredictability, threat and difficulty, in order to achieve both fertilisation and offspring survival. The perceptual models for sexual and offspring intrusion, are existentially different but they use the same emotion, though with some differences in biochemistry and register levels. Episodic and related movement modeling develops and enriches these as it does all encounter and activity.