03. Important Information Flashcards
How similar are human and chimpanzee DNA molecules
98.8%
Discuss the relation of genes to behaviour
Genes never control behaviour directly, genes are associated with behaviour through their role in building and modifying the physical structures of the body. These structures interacting with the environment produce behaviour.
How do genes affect the body’s development
through their influence on the production of protein molecules
Genes are components of extremely long molecules of a substance called
DNA
Each protein molecule consists of a long chain of smaller molecules called
amino acids
How many amino acids might each protein molecule contain
several hundred to several thousand
How many distinct amino acids are there
20
How is RNA (ribonucleic acid) formed and what does it do?
Some portions of DNA serve as templates for producing RNA which in turn serves as a template for producing protein molecules
How many genes do human beings have?
About 20,000
Does most of the DNA in human cells code for proteins?
No
Chomosomes
Contain genetic material (DNA)
How many pairs of chromosomes does the normal human cell have
23 ( 1 of which contains the sex chromosomes)
What accounts for differences in among cells in the body
Different activation of genes
Describe meiosis
Each chromosome replicates itself once then the cell divides twice. Before the first division the chromosomes exchange genetic materially randomly resulting in genetically dissimilar cell which contain only HALF of the full number of chromosomes.
When do some pairs of genes blend their effects?
When the pair of alleles are neither dominant or recessive
Who is Gregor Mendel
Austrian monk who came up with the idea that units of heredity come in pairs and that one member of a pair can be dominant over the other
Why might a disease caused by two recessive genes (such as sickle cell) persist in the gene pool?
It may provide some secondary benefit (people with sickle cell are less likely to die of malaria)
Most of the behaviourally relevant traits in humans that derive from alteration at a single gene locus are…
Brain disorders
Categorical characteristics (genes)
Are characteristics that derive from variation at a single gene locus
Continual characteristics (genes)
Account for most anatomical and behavioural differences among individuals of any species and are measurable in degree
When and by whom was the first long term selective breeding study in psychology done?
1920s by Robert Tryon
DNA Methylation…
does not alter the protein that a gene will produce, but rather influences whether the genes will produce the protein at all. Most highly methylated genes do not produce their proteins; that is, they are “shut off”
histone modification
typically results in activating DNA
Research with nonhuman animals suggests that the way the human brain “learns” to react to stress through the production and processing of the hormone cortisol is likely governed by…
Epigenetic mechanisms
List 4 core concepts of Darwin’s theory of natural selection
- There is overproduction of offspring in each generation.
- There is variation in features or traits within members of a generation.
- Individual differences are inherited from one generation to the next.
- Individuals with collections of traits that fit well with the local environment are more apt to survive and have more offspring than individuals whose traits do not fit as well with the local environment.
he genetic variability on which natural selection acts has two main sources
(1) the reshuffling of genes that occurs in sexual reproduction
(2) mutations.
Biologists and psychologists who think in evolutionary terms find it useful to distinguish between two kinds of explanations of behaviour…
distal and proximate
Some inherited characteristics are inconsequential to survival or reproduction and result from the mutation of just one or two genes. Name one
different nose shapes according to race
Why do many psychologists avoid using terms such as instinct and innate?
- They imply “no experience necessary” (associated with genetic determinism). Genes don’t determine behaviour directly
- “instinct” is not an easily defined term
The eyebrow flash is…
According to Irenaus Eibl-Eibesfeldt a universal sign of greeting among friends (what a happy surprise to see you)
How do human emotional expression illustrate the point that species-typical behaviours can be modified by learning?
In general, people can identify each emotion more easily and accurately when it is expressed by other members of their own culture. There may also be differences is the application of some behaviours (e.g. only used with children/ strangers depending on the culture)
Species typical behaviour does not mean that learning is not involved. List two species typical behaviours in humans that involve learning
Walking and use of language
What is a key difference between a behaviour listed as species-typical and one which is not?
Biological preparedness. Natural selection has equipped each species with the anatomical structures to ensure that normal individuals who grow up in normal environments will be able to perform the species-typical behaviour. (e.g. dogs are capable of learning to walk on two legs but will not do so without being motivated/ rewarded, a human child will.
Species-typical behaviours are relative rather than absolute becuase…
no behaviours stems from just biological preparedness, some sort of experience with the environment is always involved
To help determine if a behaviour is species-typical we should ask 4 questions…
- What are the environmental conditions needed for the full development of this behaviour
- What internal mechanisms are involved in producing this behaviour?
- What consequences does this behaviour have in the indicidual’s daily life?
- In the course of evolution, why would the genes that make this behaviour possible have been favoured by natural selection?
What are the two conceptually different classes of similarities across species?
Homologies and analogies
How can homologies be used to infer the pathways along which species-typical behaviours evolved?
By comparing the different forms of a particular species-typical behaviour in closely related species , it is often possible to reconstruct hot the more complex of these forms evolved through a species of steps from the simpler from
How can analogies be useful for making inferences about distal functions of species-typical behaviour?
By comparing a particular behavioural trait in different species it may be possible to find commonalties of habitat and lifestyle that are clues to the distal function of that trait
Evolutionary theory is concerned with a handful of core issues. List 3
- Mating
- Aggression
- Helping
What is the most important behaviour from an evolutionary perspective?
Mating
What are the 4 broad classes of male-female arrangement in sexual reproduction
- Polyandry
- Polygyny
- Monogamy
- Promiscuity
What is Robert Trivers’ theory of parental investment
In general, the sex that invests the most in parenting will be more selective in choosing a mate than the less invested sex, whereas the less investing sex will be more willing to compete for access to the more-investing sex
Most species of mammals are? (mating)
polygynous
In general, the more polygynous a species, the greater the size difference between…
male and female (male bigger)
Polyandry is the primary mating patter for…
some species of fishes and birds but not for any mammals
Which condition is most likely to bring about monogamy?
When conditions make it impossible for a single adult to raise the young but quite possible for two to raise them
Because of a relative lack of competition, males and females in monogamous species tend to be…
the same/ similar in size
What percentage of bird species are predominantly monogamous?
over 90%
Explain the difference between social and sexual monogamy
Social monogamy is the faithful pairing of female and male for raising young and sexual monogamy is fidelity in copulation between female and male
For what evolutionary reasons might monogamously mated females and males sometimes copulate with partners other than their mates?
Female- change to copulate with a male who is genetically superior to her own
Male- driving neighbouring males away from his own mate whenever possible and copulating with neighbouring females (pass along more of his genes)
List 2 of the most promiscuous species
Chimpanzees and bonobos
Why might promiscuity have developed in apes?
To permit groups to live in relative harmony
What is one relative advantage for female primates in promiscuous groups
paternity confusion (among many species of primates, males kill young that are not their own)
When do female bonobos copulate?
during all times of their reproductive cycle
Which (according to field studies) are the most peaceful of the primates?
the promiscuous bonobo!
Describe human mating patterns
Humans fall on the boundary between monogamy and polygyny (in no cultures are humans as promiscuous as primates)
Most human marriages are
monogamous (even in cultures that promote polygyny)
In what percentage of mammals do the male provide some support for offspring?
About 5%, the human male among them but the human female provides most physical care
Describe the male female size difference in humans
Bigger than that seen in monogamous species, much smaller than that seen in polygynous species
Describe some impact mating patterns may have on the immune system
Sexually promiscuous species tend to have more types of white blood cells than monogamous species (Humans are between polygynous and monogamous)
Which two emotions are linked to brain mechanisms that predispose humans to mating bonds?
those that promote emotions of romantic love and sexual jealousy (seen in every culture studied)
Both humans and birds experience sexual love and jealousy, are these similarities analogous or homologous?
Analogous
How does lust motivate both men and women to engage in sexual relations outside of established bonds?
Men- can send more copies of genes to next generation
Women- more likely to conceive, increase in evolutionary fitness of offspring, may result in provisions from more men
Approximately what percentage of offspring in monogamous cultures are fathered outside the relationship?
2- 10%
When does polyandry tend to occur with humans?
when one man cannot support the wife and children on his own
Define agression
Fighting and threats of fighting among members of the same species
How is agression helpful?
It helps animals acquire and retain resources needed to survive and reproduce
What motivates most of the violence perpetrated by male primates?
Sex (directly or indirectly)
Why do male primates tend to use violence against female primates?
To force copulation or prevent the female from copulating with another male
What is one of the leading causes of human men in every culture committing murder?
Sexual jealousy
Across cultures, what percentage of women experience violence at the hands of an intimate partner?
Between 19 and 75%
Define helping
Any behaviour that increases the survival change or reproductive capacity of another individual
What are the two categories of helping?
Cooperation and altruism
Define cooperation
A type of helping behaviour in which interaction among two or more individuals increases the survival chance or reproductive capacity of each individual involved in the interaction (most advantages of social living lie in cooperation)
Define altruism
A type of helping behaviour in which an individual increases the survival chance or reproductive capacity of another individual while decreasing its own survival chance or reproductive capacity
What are two evolutionist theories that explain altruism?
The kin selection theory and the reciprocity theory
Define the kin selection theory
Theory proposing that apparent acts of altruism have come about through natural selection because such actions are disproportionately directed toward close genetic relatives and thus promote the survival of others who have the same gene
Define the reciprocity theory
Theory proposing that apparent acts of altruism have come about through natural selection because they are actually forms of long-term cooperation rather than true altruism
