Psych Exam 2

Chapter 2

Natural Selection

an evolutionary process by which individuals of a species that are best adapted are the ones that survive and leave the most fit offspring

Adaptive behavior

behavior that promotes an organism’s survival in the natural habitat, because an organism possesses characteristics needed for survival

• must adapt to place, climate, food sources and ways of life

Evolutionary psychology

emphasizes the importance of adaptation and reproduction to ensure survival

• offspring that adapt → develop behaviors → possesses self protective traits

• “survival of the fittest”

Evolutionary development psychology

Daivd Buss: evolution is not just physical, but also psychological

• understanding human development

Psychological mechanisms

• domain specific: they only apply to s single aspect of a persons psychological makeup

• Ex: we developed set of problem-solving skills for recurring problems like finding food

Modularity of the mind “Swiss army knife theory”

The view that our brain is in fragments and we use each module of a different task like math, lang, ect

When do human’s use natural selection

• operates primarily on characteristics that are tied to reproductive fitness

• during the first half of life

Biological vs cultural needs

• Biologically: as we get older we get weaker

• Cultural: we lean on more resources such as cognitive skills, literacy, technology, and social support

Evolution vs. culture need

• evolution: decreases as we age

• culture: increase as we age

Alternative Bidirectional view

suggests environmental and biological conditions influence each other

Evolution does not dictate behavior

• human behavior is not fixed solely on biology

• people can build very different cultures from the same basic human biology

Criticisms of evolutionary psychology

• does not adequately valve soical/environmental factors

• relies on after the fact explanations

• can not be scientifically tested

Why is natural selection of human traits hard study

evolution occurs on a time scale that does not lend itself to empirical study

Why could someone study evolution of humans

best tested by studying specific genes in humans and other species, and their links to traits and behaviors

Genetic influence

our dna is not just inherited from our parents it includes what we inherited as a species from other species that were our ancestors

How do humans begin life

humans begin life as a single cell

What does the nucleus hold

chromosomes

Chromosomes

threadlike structures made up of deoxyribonucleic acid

DNA

a complex double heilx molecule that contains genetic code or info

Genes

units of hereditary info composed of DNA

• helps cells to reproduce themselves

• manufacture the proteins that maintain life

Where are genes located

each gene has its own location its designated place on a particular chromosome

What is todays research trying to do

striving to discover the specific location of genes that are linked to certain functions and developmental outcomes

The human genome project

efforts to map the human genome- the complete genetic content of our cells, which includes developmental info used for creating proteins that contribute to th emaking of humans

How many genes do humans have

around 22,000

Gene to protein raito

humans have far more protein to genes, there is not a one-to-one correspondence

The dependent gene

• David Moore

• gene does not act independently

• huamn genome consists of many genes that collabortae both with each other and with non genetic factor inside and outside the vody

Genetic expression

the activity of genes is by their environment (inside and outside the body)

• EX: hormones in the blood can turn genes on and off

Certain genes are turned on or off as a result of exercise, mainly through..

Methylation

• tiny molecules attach themselves to the outside of a gene, making the gene less capable of receiving and responding to biochem signals from the body

Genes are negatively affected by

stress, exercise, nutr, radiation, temp, and lack of sleep

Human cells have..

46 chromosome in 23 pairs, except sperm and eggs

Mitosis

the cellular reproduction in which the cells nucleus duplicates itself into new cells

• each contains the same DNA as original cell

Meiosis

cell division forming eggs and sperm (gametes)

Fertilization

the reproduction stage when egg and sperm fuse to create a zygote

Zygote

a single, formed through fertilization, in which 23 unpaired chromosomes from the egg and 23 unpaired chromosomes from the sperm

Members of each pair of chromosomes

They are both similar and different: each chromosome in the pair contains varying forms of the same gene, at the same location (hair color gene but one is brown, the other is blonde)

The sex chromosomes

• the 23 pair

• females: 2 x

• male: x and y

sources of variability

combining the genes of two parents in offspring increases variability in the population

• the chromosomes are brought together in the zygote in a unique combination

Identical twins

• monozygotic twins

• single zyote splits into two genetically identical replicas and becomes two individuals

Fraternal Twins

• dizygotic twins

• two eggs fertilized by different sperm create two nonidentical zygotes as genetically similar as ordinary siblings

Mutated gene

a permanently altered segment of DNA

• mistake by cellular machinery, damage from environmental agent

Susceptibility genes

genes that make the individual more vulnerable to specific diseases or accelerated aging

longevity genes

genes that make the individual less vulnerable to certain diseases and more likely to live to an older age - daf-2, 16

Genotype

a person’s genetic material

Phenotype

how an individual’s genotype is expressed in observable and measurable physical and psychological characteristics

Expression is also influenced by..

• environmental factors

• ex: genetic potential for heigh may be stunted by lack of access to proper nutr

Genetic perinciples

determine how a genotype is expressed to create a particular phenotype

Dominant- recessive genes principle

one gene of a pair always exerts its effects, overriding the potential influence of the other gene

sex linked genes

when a muted gene is carried on the x chromosome, the result is called x linked inheritance

• most x linked inherited diseases manifest in males, who have only one x chromosome

• females have 2 x chromosomes, which is unlikely to be changed

Genetic imprinting

occurs when the expression of gene has different effects depending on whether the gene is passes on by mother or father

• a chemical process prevents one member of the gene pair from expressing itself “silent”

Effects of genetic imprinting

it is normal but can go awry, disturbing development and leading to growth disorder/cancer

Polygenic inheritance

many different genes interacting plus environmental influences, determine a characteristic or developing disease

Gene-gene iinteraction

studies focusing on the interdependence of two or more genes in influencing characteristics, behavior, diseases, and development

Down Syndrome

a form of an intellectual disability caused by the presence of an extra copy of chromosome 21

• concause intellectual and physical issue