lOMoARcPSD|383 406 3
HC 1 03/09/2018
Genes and evolution
Multiple-choise exam
October 22, 2018, 15:15-1745
Psychology is the study of mind, brain and behavior. Using the scientific method
because common sense fails.
Is it correct to claim that “ a violent person has violent genes” ?
In the seventies they said that the environment cause (violent) behavior.
In the nineties they said the genes causes (violent) behavior. Genetic make-up
is crucial for determining how this person is behaving.
Today they say that it is the combination of genes and environment that causes
(violent) behavior. Genes send out the possibilities and environment
determines whether these characteristics come out.
Genes are meaningful sections of the DNA molecule they:
Govern the cell’s functioning by providing
instructions for making proteins:
Where
When
How much
Gene expression
Whether a gene is turned “on” or “off”; the extend to which an gene
is transcribed intro a sequence of amino acids (protein)
In each cell, some genes are expressed at any point in time and others are
not. This is controlled by the biochemical environment inside the cell.
, lOMoARcPSD|383 406 3
The biochemical environment inside the cell is influenced by e.g., the
environment outside the cell, timing in development, the overall
environment, experience, behavior.
The genotype is an organism’s specific set of genes. The phenotype is the overt traits and
behaviors of an organism. Phenotype is determined by genotype x environment
(experience, past and present)
Monozygotic (identical) twins have the same genotype
but different environments.
An eggcell has 23 chromosomes and a spermcell also has 23
chromosomes. A baby has 46 chromosomes. The pairs are located
at corresponding positions on pairs of chromosomes.
Each gene is paired with another gene. The pairs
are located at corresponding positions on pairs on
chromosomes.
An allele is one specific variant of a gene. You
have dominant alleles and recessive alleles.
Homozygote: Alleles on locus are the same
Heterozygote: Alleles on locus are different
A specific trait or behavior is determined by the
interaction between the environment (past and
present) and
- One gene pair
- Multiple gene pairs: polygenetic inheritance
The genome is shaped by evolution over the years -> Darwin’s evolution theory
Evolution by natural selection
Charles Darwin hypothesized that all modern organisms:
- Are descender from a small set of shared ancestors
- Have merged over time through the process of
evolution The key mechanism of evolution is natural selection
- Three conditions:
1. There is variation among individuals of a populations
2. Individuals with a certain trait survive and reproduce at higher rates
than others
3. The trait associated with this advantage is passed from parents
to offspring
This specific trait will be better represented in the next generation.
Organisms differ in genotype and variations in genotype are passed from generation
to generation. What matters is the survival of the genes, not the survival of
individuals. The evidence for modern evolutionary theory comes from many sources
- The fossil record
, lOMoARcPSD|383 406 3
- The resemblance between genomes of various organisms.
- Pseudogenes
- Distribution of species across the world. Continental islands versus oceanic
islands.
Despite overwhelming evidence, many people remain skeptical about the theory of
evolution. Results of survey (2005): “ Human beings, as we know them, developed
from earlier species of animals.”
It does not follow that evolution
- Somehow improves organisms
- Can only lead to rigid behavioral patterns
Genes and behavior
Nature versus nurture
- The nature (genes) nurture (environment) debate has become
increasingly irrelevant.
- Instead there is continuous interaction between genes and environment!
Who we are is determined by how our genes are expressed in distinct
environments. Is it correct to claim that “a violent person has violent genes” ?
Genes <-> Environment <-> (criminal) behavior
MAOA allele for low MAO activity <-> Severe maltreatment <-> high probability of
being convicted of violent crimes
Behavioral genetics
- The study of how genes and environment interact to influence psychological
activity
Methods
- Twin studies
- Adoption studies
HC 1 03/09/2018
Genes and evolution
Multiple-choise exam
October 22, 2018, 15:15-1745
Psychology is the study of mind, brain and behavior. Using the scientific method
because common sense fails.
Is it correct to claim that “ a violent person has violent genes” ?
In the seventies they said that the environment cause (violent) behavior.
In the nineties they said the genes causes (violent) behavior. Genetic make-up
is crucial for determining how this person is behaving.
Today they say that it is the combination of genes and environment that causes
(violent) behavior. Genes send out the possibilities and environment
determines whether these characteristics come out.
Genes are meaningful sections of the DNA molecule they:
Govern the cell’s functioning by providing
instructions for making proteins:
Where
When
How much
Gene expression
Whether a gene is turned “on” or “off”; the extend to which an gene
is transcribed intro a sequence of amino acids (protein)
In each cell, some genes are expressed at any point in time and others are
not. This is controlled by the biochemical environment inside the cell.
, lOMoARcPSD|383 406 3
The biochemical environment inside the cell is influenced by e.g., the
environment outside the cell, timing in development, the overall
environment, experience, behavior.
The genotype is an organism’s specific set of genes. The phenotype is the overt traits and
behaviors of an organism. Phenotype is determined by genotype x environment
(experience, past and present)
Monozygotic (identical) twins have the same genotype
but different environments.
An eggcell has 23 chromosomes and a spermcell also has 23
chromosomes. A baby has 46 chromosomes. The pairs are located
at corresponding positions on pairs of chromosomes.
Each gene is paired with another gene. The pairs
are located at corresponding positions on pairs on
chromosomes.
An allele is one specific variant of a gene. You
have dominant alleles and recessive alleles.
Homozygote: Alleles on locus are the same
Heterozygote: Alleles on locus are different
A specific trait or behavior is determined by the
interaction between the environment (past and
present) and
- One gene pair
- Multiple gene pairs: polygenetic inheritance
The genome is shaped by evolution over the years -> Darwin’s evolution theory
Evolution by natural selection
Charles Darwin hypothesized that all modern organisms:
- Are descender from a small set of shared ancestors
- Have merged over time through the process of
evolution The key mechanism of evolution is natural selection
- Three conditions:
1. There is variation among individuals of a populations
2. Individuals with a certain trait survive and reproduce at higher rates
than others
3. The trait associated with this advantage is passed from parents
to offspring
This specific trait will be better represented in the next generation.
Organisms differ in genotype and variations in genotype are passed from generation
to generation. What matters is the survival of the genes, not the survival of
individuals. The evidence for modern evolutionary theory comes from many sources
- The fossil record
, lOMoARcPSD|383 406 3
- The resemblance between genomes of various organisms.
- Pseudogenes
- Distribution of species across the world. Continental islands versus oceanic
islands.
Despite overwhelming evidence, many people remain skeptical about the theory of
evolution. Results of survey (2005): “ Human beings, as we know them, developed
from earlier species of animals.”
It does not follow that evolution
- Somehow improves organisms
- Can only lead to rigid behavioral patterns
Genes and behavior
Nature versus nurture
- The nature (genes) nurture (environment) debate has become
increasingly irrelevant.
- Instead there is continuous interaction between genes and environment!
Who we are is determined by how our genes are expressed in distinct
environments. Is it correct to claim that “a violent person has violent genes” ?
Genes <-> Environment <-> (criminal) behavior
MAOA allele for low MAO activity <-> Severe maltreatment <-> high probability of
being convicted of violent crimes
Behavioral genetics
- The study of how genes and environment interact to influence psychological
activity
Methods
- Twin studies
- Adoption studies
