I took an alternative route to work recently along a windy country road to avoid flooding on the main road. I had little time to spare. I turned a bend and, to my annoyance, saw the road was blocked by a long line of cows slowly filing along and entering a farm-yard ahead. I stopped at the point where the cows were coming from a side road onto "my" road. The end of the line soon appeared and ambling behind the last cow was a sheepdog who was in charge of bringing the cows home.
The dog looked up, saw my fussed face and, it seems to me, understood he was holding me up. He sprang into action, barking and snapping at the ends of cows' long tails. He ran up and down the line of cows as well as pushing from the rear. Pretty soon the whole line was running.
Every so often the dog looked back at me to see how this was going down. In no time, all the cows were in the farm-yard. The dog stood at the gate and watched as I drove by. I saluted it.
The inner life of animals is a large area, covering the capacity of animals to think, to anticipate, to experience emotions, etc. Most scientists who study animal behaviour shy severely away from entertaining the concept of inner life, tending to view animals as living machines that respond to the world automatically, along paths predetermined by biological hard-wiring.
Earlier workers were not so cautious. Charles Darwin believed dogs have a sense of humour. He noted that, often, when an owner throws a stick, the dog will rush, seize the stick and wait until the owner arrives to retrieve it, whereupon the dog will run farther away with the stick before the owner can grab it, wait and repeat the manoeuvre, etc. It was obvious to Darwin the dog was playing a practical joke.
Modern animal behaviourists would label Darwin's interpretation as anthropomorphism (i.e., falsely imprinting human motivations on unconscious reflexive animal behaviour). One fascinating area of animal behaviour is where animals deceive. Deception is a sophisticated process, requiring planning, faking, and possibly the ability to visualise another's inner world. Is this deception simply a hard-wired and reflexive behaviour pattern, is it conscious brain-power, or is it a mixture of both?
A well-known example of animal deception occurs when you stray too close to the nesting young of certain birds. The mother bird suddenly appears close to your feet and scurries away from the nest feigning a broken wing. The idea is to offer the predator a juicy vulnerable target, thereby attracting the predator away from the nest. If you catch up closely with the "injured" bird, it suddenly explodes away into flight.
Studies have shown that this deceptive behaviour is not entirely a reflexive reaction. For example, the bird looks backwards to see if she is being followed, and, if the pursuer falters, the bird changes her tactics, usually by squawking louder or running closer to the intruder.
The theory of evolution proposes that natural selection (changes in a species that confer a reproductive advantage) drives the changes that occur in a species over time, and the conventional theory holds that change proceeds in small increments. How could deceptive behaviour arise and develop in this scenario?
The simplest forms of deception, found commonly in nature, are camouflage and mimicry. For example, many insects that live on leaves bear such a close resemblance to the leaf it is almost impossible to spot them. Many plants have developed the power of mimicry to an exquisite level.
For example, some species of orchid depend on a certain species of wasp for reproduction - i.e., to carry out cross-pollination between plants. The orchid flower closely resembles the female of the wasp species. It has an opening located so that when the male wasp copulates with the flower, the insect can just reach the pollen produced by the flower. The wasp makes amorous journeys from flower to flower carrying the pollen.
At first glance it appears the wasp/orchid mechanism works only because the orchid flower bears an exact resemblance to the female wasp. One would imagine that a crude resemblance between the flower and the female wasp would not be good enough to fool the male. How could this mechanism have gradually evolved from simple, crude beginnings? Well, it could have, and Richard Dawkins convincingly explains why in his book, River Out of Eden (Weidenfeld and Nicholson, 1995). Wasps are not that hard to fool.
BUT how could altruistic behaviour such as displayed by the broken-winged bird have evolved by natural selection? After all, such behaviour puts the practitioner at extra risk and one would imagine it would find no favour with natural selection because it diminishes the prospects of successful reproduction in that individual.
Socio-biologists explain the evolution of altruistic behaviour by taking a genes' eye view of evolution and seeing it as a process whereby genes strive to project copies of themselves into the future. Ones genes are not only contained in offspring, they are also present in relatives. Often, when animals seem to behave as altruistically as individuals, they are also being genetically selfish since their behaviour enhances the prospects of transmitting their genes (present in relatives) to the next generation.
This genetic explanation does not rule out the parallel evolution of emotional and cognitive capacity. Is the bird that lures the predator away from the nestlings simply carrying out a mechanical reflex or is its brain, to some extent, figuring out the next move and its heart pounding with fear because its babies are in danger?
William Reville is a senior lecturer in Biochemistry at UCC.