Animals having to learn escape responses by experience, rather than using

‘instinctive’ fleeing or freezing reactions.

You can imagine hundreds of other possible deviations from efficient devel-opmental paths, which will be penalized by natural selection. Although each metabolic decision is made independently at each moment, natural selection in every generation rewards genetic changes that anticipate regularly appearing challenges in the environmental niche along the lifetime developmental path.

This means that adapted organisms already inherit pre-programmed develop-mental paths in which resource needs for an efficient path are anticipated and prepared for. Examples are laying down of reserves of fat for anticipated future Fig. 10.3. A potential guide dog showing a certain amount of fear towards the handler.

needs, giving young animals emerging from safe nests an instinctive fear of unfa-miliar beings and giving nestling birds on cliff ledges a similar ‘fear of heights’.

As the environment selects organisms in development programmes, what roles do genes play? Every development programme is guided by the information in the particular set of genes put into the zygote by both parents. Whether genes prosper depends on how well the developmental path launched and guided by the genes of each zygote or clone is able to handle the challenges of the local envi-ronment. Developmental paths of organisms are continually under pressure, metabolically, to keep the organism alive. In the products of evolution which nature has provided, there is very little scope for an individual animal, on its development path, to ‘take it easy’. This is why animal breeders are unlikely to change animals usefully, without paying a biological cost, when they add a new feature or exaggerate an existing one. Breeders’ wishes involve costs.

We can summarize the consequences of resource allocation theory as follows.

The model of fitness as stated in our equations is a simplification. A living organ-ism should be seen as a developmental path from the fertilized zygote to death.

Genes influence this path. Natural selection eliminates all organisms that at any Fig. 10.4. Detector dog coming off a boat.

moment have insufficient metabolic resources to cope with the next challenge from the environment and discriminates against all those not using available resources efficiently. This in turn selects for the putting down of reserves for pre-dictable changes in resource needs, such as seasonal or pregnancy-related extra efforts. Organisms inherit programmed lifetime developmental paths. These pro-grammes include mechanisms for adjusting reproductive effort to the environ-ment. In each environmental niche there are optimal sizes and optimal developmental paths. Natural selection uses the processes of genetic canalization and genetic assimilation to achieve optimal lifetime paths. Deviations from optimal sizes and optimal developmental paths incur metabolic costs. These typ-ically lead to reductions in reproduction and longevity. ‘Premature’ ageing is a consequence of above-optimal resource use, often early in the lifetime path.

Behaviour is classified into several categories. Reflexes, instinctive behaviour and learned behaviour are behaviours that are important to working dogs.

Reflexes are responses to stimuli before the animal becomes aware or conscious of the stimulus. Instinctive behaviour is that behaviour which occurs when a stim-ulus is encountered for the first time. Both reflexes and instinctive behaviour are the direct result of natural selection in the evolution of animals. In the develop-mental path of an adapted animal, the animal must be able to deal with a stimu-lus the first time it experiences it. Hence, both reflexes and instinctive behaviour need to be essentially correct the first time the appropriate stimulus situation is experienced. Reflexes include responses to gravity or to pressure on the body and withdrawal responses to hot or painful stimuli. Instinctive behaviour includes avoidance of cliff edges and unfamiliar beings outside the familiar nest, the sexual reactions by males to females and vice versa and reactions between mothers and newborn young. Any animal that reacts falsely is left behind by natural selection.

So reflexes and instinctive behaviour in normal healthy animals are dependable and appropriately motivated. The level of motivation also results from natural selection. Clearly, instinctive behaviour and motivational level of working animals will also respond to artificial selection by humans and they are very important to successful breeding programmes.

Learned behaviour relies on making associations between stimuli and behav-ioural responses. This process is known as conditioning. Classical conditioning is the provision of a neutral stimulus, like a sound, shortly before providing food.

Provision of food automatically stimulates the eating response and all its motiva-tions. If the sound reliably predicts the arrival of food, the sound becomes the con-ditioned stimulus which by itself releases the motivations associated with eating, and the eating itself if food then appears. Repeatable signals preceding the regular feeding of animals in zoos or livestock in droughts become strong conditioned stimuli.

Instrumental conditioning (see also Chapter 8 in this volume) is the process where a stimulus places the animal under some stress. If the reaction of the animal relieves the stress, the animal associates its reaction with removal of stress and, provided signals are clear and consistent, behaviour will become shaped such that stress is minimized. Such instrumental conditioning is very important in training

dogs and horses into precise behavioural responses. For many working dog situa-tions, both classical and instrumental conditioning play a part. Breeding pro-grammes are likely to be less affected by learned behaviour than by instinctive behaviours. Selective breeding will readily change motivation levels associated with instinctive behaviour. It is difficult to see how selective breeding will affect the speed by which dogs make associations.