Chapter 1- Introduction Flashcards
The tendency for characteristics that contribute to the survival of a species to persist, and for those that do not to disappear
Natural selection
Darwins theory was published in 1859
He did not understand the genetic basis of variation. Gregor Mendel discovered the genetic basis for natural selection
Darwin gave examples in nature: how animals coats get thicker when the climate turns gradually colder
Describe Richard Dawkins pebbly beach analogy
In a pebbly beach, the pebbles are not arranged at random, the smaller pebbles tend to be found in segregated zones running along the length of the beach, the larger ones in different zones are stripes. The pebbles have been sorted, arranged, selected, but without intelligent intervention. It is from the mechanical, unthinking force of the waves as big stones and small stones are affected differently by the waves and end up in different places
Describe the evolution of characteristics of the peppered moth
Feeds at night and rests during the day on the trunks and limbs of trees. Survival depends on its ability to escape detection. At one time these moths were a mottled light gray colour which resembled the lichen-covered trees, and a rare black variation stood out against this background which made it highly vulnerable. Pollutants in industrial areas killed the lichen and a darkened the bark of trees, which made the light coloured moths fall more increasingly as prey, whereas the dark moths tended to survive and reproduce. Near industrial centers, the black had increased in number and the light ones declined
Describe the grants study of the finches of the Galápagos Islands
Two species of finches ate the Caltrop seeds , The ones with the beak 11 mm long could crack the shell, and ones with a beak 10.5 mm long could not. During severe drought when the seeds are the only food available, the average beak size increased as birds with smaller beaks died off but when the rains finally returned and larger seeds became harder to find, the smaller beak birds had the advantage
Significance: small differences and changes make big differences. Depends on the changes in the environment
Any change in a gene. When the modified gene occurs in a reproductive cell, the mutation may be passed on to offspring
Mutation
A relationship between a specific event and a simple, involuntary response to that event. Usually refers to an unconditioned one
Reflex
Describe the reflexes that exist in the amoeba
Protects the amoeba from injury by immediately withdrawing from noxious substances. Minimizes the harmful effects of the substance
When encounters some edible objects, it immediately responds by engulfing it and making a meal of it
Describe the salivary reflex
Important for food consumption. The flow of saliva that begins the process of digestion and trigger swallowing
When reflexes fail to function properly. It may happen as a result of an allergic reaction to medication or as a result of injury or disease or in people who have consumed excessive amounts of alcohol or other drugs that depress the central nervous system
Reflex failure
Example: death from alcoholic intoxication when alcohol interferes with the respiratory reflex or when the intoxicated person vomits inadequately and chokes to death
An increase in the intensity or probability of a reflex response resulting from earlier exposure to a stimulus that elicits that response
Sensitization
Describe Powell and Holtzmans work that illustrates how sensitization works in the context of drug addiction
May play a role in drug addiction. Animals given an addictive drug over a period of time are later more sensitive to their effects. Gave rats morphine for 1 to 2 days and then tested their reaction to the drug after a period of abstinence. The rats showed an increased response to morphine, sensitization, for up to three months after their last dose
A decrease in the intensity or probability of a reflex response resulting from repeated exposure to a stimulus that elicits that response
Habituation
When babies first hear a noise they respond with an increase in heart rate but with repetition of the noise at regular intervals, the change in heart rate becomes less and less pronounced until in some cases, the noise has no measurable effect at all
What is the relationship between fetal habituation and intellectual development after birth
Slow fetal habituation tends to be associated with difficult pregnancy, and there is some evidence that the rate at which a foetus habituates is correlated with intellectual development after birth and may one day be used to identify prenatal medical problems
Who originally said that change is the only constant?
The Roman philosopher Lucretius 2000 years ago
The world is constantly changing although our time here is too brief to notice
Any largely inherited series of interrelated acts, usually elicited by a particular stimulus (the releaser). Formerly called instinct
Fixed action pattern
Used to be called instincts, but this term is no longer used because it came to refer to any more or less automatic behaviour
Give an example of an FAP that is useful for survival
Provides protection from predators. The house cat arches it’s back, hisses, growls, and flicks its tail when confronted by a threatening dog
What domains of behaviour are included in fixed action pattern’s?
Protection from predators and against the elements. Procuring food, courtship and mating, the care and rearing of the young
Any stimulus that reliably elicits a fixed action pattern
Releaser or releasing stimuli
Ex: The male rat ordinarily will mate only with females that are in estrus or in heat. The odorous chemicals released by the female rat, called pheromones, act as releasers for sexual behaviour in the male
What is a releaser for aggression in the mail Stickleback fish
The red colouration on the male abdomen
Describe the fixed action pattern of tropical army ants that suggests they are engaging in intelligent behaviour
Entire colonies of these ants charge across the forests in what appears to be a highly organized, intelligently directed campaign, when in fact they are merely following a chemical trails laid down by the ants ahead of them
Give an example of how a fixed action pattern may be selected due to gradual changes in the environment of a species
Geological changes that increase the steepness of a slope that salmon must swim across. Those fish with the ability to make the trip will breed successfully reproduce their kind, whereas those not up to the challenge will fail to reproduce and as these geological changes continue to increase the difficulty of the task, the process of natural selection will produce a salmon capable of mastering it
Do humans have fixed action pattern? Describe the arguments for and against this idea including Freud’s views
It is hard to say, many researchers today maintain that there are no fixed action pattern’s in human beings, and that those previously attributed to people lack the monotonous character of webs spinning and spiders and nestbuilding birds. The fixed action pattern’s attributed to humans vary from person to person and in each individual and from culture to culture and from time to time, the complexity and variability of these attributes is a far cry from stereotypic behaviour of most other animals
Some people think that incest taboo is a fixed action pattern but Freud pointed out that if there really is this natural aversion to incest, there would be no need for an incest taboo, it is a cultural invention designed to avoid problems caused by incest
The innately emotional affiliation of human beings to other living organisms
biophilia
Any general behavioural tendency that is strongly influenced by genes. Examples include introversion and general anxiety
General behaviour traits
How do general behaviour traits differ from fixed action pattern?
Fixed action patterns are elicited by fairly specific kinds of environmental events called releasers. Behaviour traits, however occur in a wide variety of situations
There are differences in the plasticity of the behaviour. Fixed action pattern’s generally occur in the same way, where as general behaviour traits are far less stereotypic and maybe different between individuals
Any stimulus the removal of which is reinforcing; characterizing an event that is likely to be avoided
Aversive
What problem is there with aggression as a fixed action pattern with aversive’s as releasers?
Aggressive behaviour caused by aversives can be caused by many different things, whereas fixed action pattern’s are not released by so many different kinds of events
Does heredity play a role in the appearance of general behaviour traits?
Yes, selective breeding can, for example, produce strains of animals differing in fearfulness aggressiveness, activeness and addiction proneness
If a particular behaviour trait is selected by the environment over many generations, there can be profound changes in the species. In one study, researchers selectively bred foxes on the basis of general behavioural characteristics, meeting only those foxes that were most dog like in behavior, which was least fearful of an aggressive toward people. After several generations, the fox behaved more like dogs and less like foxes and became more dog like in their physical appearance
What is the chief limitation of natural selection and what kind of changes does natural selection have difficulty dealing with?
As a way of coping with change, natural selection is slow. It does not produce helpful changes in individuals living now but to those who will inherit these traits later.
Limited value in coping with abrupt changes
Ex: The sudden appearance of a new predator or a sudden change in temperature
Another limitation: no value whatever in helping living individuals cope with change, evolutionary changes always behind the times
Describe Cronks views about how behaviour that defies explanation can be caused by forces of natural selection
Some behavioural and physical adaptations that seem to make no sense in the current environment can be traced to the legacy of an earlier, different environment in which those traits were favoured.
Ex. The rabbit that has learned to dodge back-and-forth when pursued by predators is not helpful in eluding vehicles on the highway
BF Skinner said that people can be hostages to their genetic history. What does this mean? Give an example.
What was good for humans at one point may not be good for them now. Individuals who had a natural preference for salt and sugary foods or more likely to get the calories needed for survival, but in industrial societies where these things are abundant, people are consuming too much and endangering our health
A strong appetite for sexual contact favourite the survival of our species for thousands of years, but advances in the last 200 years have greatly reduce mortality rate of of our young so we no longer need this drive is much and now the planet is overpopulated
A change in behaviour due to experience
Learning
Explain the relationship between learning and natural selection
The ability to learn is itself the product of natural selection. Learning may be thought of as a crowning achievement of evolution, it is an evolved mechanism for coping with the challenges of a changing environment
What does evolved modifiability mean?
Learning gives the individual the tendency to modify its behaviour to suit a situation.
What advantage does learning have over reflexes, fixed action pattern, and general behavioural traits?
It enables the organism to adapt to situations for which it’s largely innate behaviour is inadequate
Ex. The avoidance of eating poisonous food, where the innate preferences are not always perfect: some items that taste bad are nutritious, and some that he’s good are deadly. To survive this danger an animal or human must learn to avoid eating the harmful items
Anthropologist Shirley strum studied the behaviour of baboons and concluded that the wise animals, rather than the strong ones, held the real power. Describe this research and explain how she came to this conclusion
The highest ranking males were the most aggressive, taking what they wanted such as sexual favors, or food. But the aggressive males did not have the greatest success with females or got the best food, the lowest ranking at least aggressive ones did because they used a kinder, gentler approach to getting what they wanted, and it worked.
The most aggressive males were generally newcomers, and the least aggressive or the long-term members of the group, which led her to believe that with time, the newcomers learn to use other, more effective techniques
Describe Bertrand Russell’s views about human superiority over other species
Whenever humans trying to prove their uniquely human characteristics that sets them apart from lower organisms, these characteristics have been found another species. May be the only uniquely human characteristic is that we are the only creature that spends time trying to prove it superiority over other creatures, the rest of the animal kingdom treats the matter with indifference
