Psychology Chapter 3

evolution

the long term adaptive process, spanning generations, that equips each species for life in its changing natural habitat

relationship between genes and behavior

genes never produce or control behavior directly they are associated with behavior, all genes that contribute to the body’s development are “for” behavior since all parts of the body are involved in behavior

structural proteins

forms teh structure of every cell in teh body

enzymes

controls rate of every chemical reaction in every cell

genes

are components of extremely long molecules of DNA

they exist in egg or sperm cell that join to form a new individual, they replicate during cell division during body’s growth and development

nucleus of a cell

a replica of your whole unique set of DNA, in each body’s cell

it serves to code for and regulate the production of protein molecules

protein molecule

consits of a long chain of smaller molecules called amino acids

amino acids

at least 20 distinct ones in every form of life on earth, arranged fifferently to form different protein

RNA

some portions of DNA in cells serve as templates for producing RNA, which serve as a template to produce protein molecules

coding genes

they code for unique protein molecules

regulating genes

work through various biological means to help activate or suppress specific coding genes and they influence body’s development

environment

every aspect of an individual and their surroundings except the genes itself

food

a part of the environment, supply genes with amino acids which are needed to create protein

environemntal effects

turns genes “off” and “on”, influencing bodily changes and altering behavioural capacity

eg physical excerse modifies chemical environment of muscle cells, activating genes that produce further growth of muscle cells

infleunce of environment(s)

internal chemical encironment activates gene activity, producing proteins, reinfluencing internal environemnt as well as physiological systems, which are ifnelucnes by external environment as well

physiological systems infleucne behavior, which infleucnes internal environment

activated gene

from continious exposure, actviated through sights, sounds, and smells, teh gene produces a proein molecule that stimulates activtly in a specific cluster of brain cells which are crucial for the motivation and organization of such behavior

environmental induction of gene activty

external factors, such a slight and temp, can change gene expression without altering teh DNA sequence

experience activated genes

tehy produce proteins which alter function of some neural circuits in the brain and changing behavior = learning

genotype

the set of genes that individuls inherit

phenotype

the observable properties of the bodily and behavioral traits

• two individuals with teh same genotype can be different in phenotype as a result of their different environments

chromosones

the genetic material, DNA, exist in each cell in structures re called chromosomes which usually disperse throughout the cell nucleus,

human cell

contains 23 pairs of chromosones, 22 are true pairs where botha re female and male,

the remianing pair determines the sex, two lareg chormosones is female, XX

mitosis

when cells divide to produce new cells other than egg or sperm cells, each chromosone replicates itself and then teh cell divides wiyh one copy of each chromosone moving inyo each og the two cell nuclei thsu formed

meiosis

when cell divide to produce egg or sperm cell

each chromosone replicates once, but the cell divides twice, before first ell divison, teh chromosone of eac pair line up next to each other and exchange genetic material ina. random manner

• resulting each egg or sperm cell is genetically different and contains half of the full number of chromosones

zygote

a single new cell after reproduction, containg full 23 pairs of chomrosones

it grows udner mitosis to form a human

benefits fo reprodiction

all unique thus les slikely to all die off when a change in environment occurs

identical twins or monozygote

fromed when two bundles of cells seperate form each other during early mitosis divisons, following a formation of a sygote,

fraternal twins or dizygote

orginate form two zygotes, each formed form different eggs and sperms, they have the same degree of genetic similarity a siblings

homozygous

the two gebes that occupy the same locus, loactaion, on a pair of chomosones thata re identical

heterozygous

two genes that occupy the same locus but are not identical

alleles

different genes that can occupy the same locus and thus can potentially pair withe ach other

dominant gene or allele

will produce its observable effect in either the homozygous or heterygous condition

in. corss bred every ¾ is dominant

a recessibe gene

will only produce its effect in teh homozygous condiyion

not all pairs of alleles manufest in a dominant or recessive gene

purebred strains

they are homozygous for all

categorial characteristics

characteristics that derive from vraiation at a single gene locus, they are sharply different rgoup form other

continious characteristics

the measures talen from indicudalsdo not all into two or more distinct groups but can lie in a observable range

normal distribution

most scores fall near the middle of teh range and the freqency appears off toward teh two extremes

polygenic characteristics

they vary in a continious way and are generlaly effected by many genery and by varaition in environment

selective breeding

to the degree that individuals within a species differ in any measurable characteristics can be modified over successive generations

• individuals mate that lie toward the same extreme on teh measure

single gene has immdiate effect

polygene has gradual effect

robert Tyron 1942

he is know for the first long term, systematic study on sleectvie breeding

• he wanted to demonstarte behavior could be infleunced by teh variation in genes

• he mated rats best at solving mazes, after the 7th generation teh ere was almsot no overlap between two distinc rats

• he even changed mothers showing regardless of how raised still same outcome

• the change was in a sensory, motor, or learning charactertic,

epigentics

changes in gene fucntion that do not alter its underlying structure of DNA, result in genes being switche don and off in a reversibale way

• how genes are activated or deactivated in different contexts

methylaction

it does not slter the protein that a gene will produce but rather influences wheter teh genes will produce teh protein at all

• methyled genes do not produce protein thus are ‘shut off’

• occurs natirally and infleunced by experience

eg:Researchers found that pregnant women’s hardship during Quebec’s 1998 ice storm was linked, 13 years later, to changes in DNA methylation in their children’s immune-system genes.

artificial selection

human-controlled selective breeding

natural selection

dictated by the obstacles to survival and reproduction that are imposed bu the natural environment; predators temp extremes

Darvins concept of natural selection

1. more individuals are born than survive

2. variation in a generation of features and traits

3. individual differences are inherited

4. individuals with collection of traits that fit well with local environment are more likely to survive

selected for

any inherited trait that increases number of offspring, trait passed on

selected against

any inherited taht the descreses the number of offsprings with gene

sources of gentic variability on which natural selection occurs

1. reshuffling of genes that occurs in sexual reproduction

2. mutations

mutations

erros that occasionally and unpredictably occur during DNA replication, causing the replica to be not quite idneitical to original

• natiral selection usually weeds out mutations

• tehy cna be usefyl, producing proetin that affects the orgnaism, increasing ability to preproduce

naturalistic fallacy

claiming that because something is natural it is good and vice versa

functionalism

the attempt to ecxplain behavior in terms of what it accomplishes for teh behavior

Distil explanations of behavior

explanations of the evolutionary level. tehy are statements of teh role that teh behavior has played in teh survival and reproduction over evolutionary time viewed form teh vantage point of gene

• looks inregards to reproduction and survival

ultimate causation

or distil causation, long term evolutionary causes of a trait or behavior, natural selection

proximate explanations of behavior

explanation that deal not with function but with mechanism statements of immediate conidtions insde and outside of animal, taht elict behavior

vestigial characteristics

anatomical structures or behavior in a species that have lost their original function over evolution

• culture lifestyles and habitats changes drastically so and so fast, however some inherited tendencies remain

adaptation

the ability to process of an individual adjusting their thoughts, feelings, and behavior to cope iwth new environmental conditions

genetic drift

variation due to chance alone without selection

why we use innate rather than instinct

• they imply ‘no experience necessary’, believes genes infleunce behavior directly rather though indirect means of working with environment to build/modify biological structures that produce behavior

• not easily defined

genetic determinism

the belief that genes determine behavior independent of experience

deterministic fallacy

implying that one form of behavior or another in unavoidable because it is controlled by our genes

6 basic emotional expressions

surpise, fear, disgust, anger, hapiness, and sadness

shwoing some human expression do not have to be learned through obserrving or hearing them

we are biologically predisposed to express certiain emotions in certain species-specfiic behevior

Eibl-Eibesfeldt 1975

found that despite its cross-cultural similarity in form and general meaning, large cultural differences exist in the use of teh eyebrow flash

• peopel can identify each emotion more easily when its expressed by other members of their culture

development of species typical behavior

learning is critical to develop tehse behavior, such as learing to walk or talk by what is being heard and seen around,

training is also required

it is relative not absolute

biological preparedness

innate, evolutionary predisposition of organisms to learn specific associations more easily than others, particulary those adapt to survival

queastions to ask when studying a particular behavior

What are the environmental conditions needed for the full development of this behavior?

What internal mechanisms are involved in producing this behavior?

What consequences does this behavior have in the individual’s daily life?

In the course of evolution, why would the genes that make this behavior possible have been favored by natural selection?

homology

any similarity tat exists because of the different species’s common ancestary

• 98% DNA is shared of apes and humans, but not because humans eveolved form apes but share a common ancestary

analogy

any similarity taht stems not from common ancestry but form convergent evolution

convergent evolution

occurs when different species because of same similarity in habitat or lifestyle independently evolve a common characteristic

physiological mechanism of behavior

research in hwo the brain and other biological structures operate to produce the behavior studied

if studying for humans on animals, must be species where behavior is homologous to humans

four broad classes of mating

polygyny, polyandry, monogomy, promiscuity

polygyny

one male mates with more tahn one female

polyandry

one female mates with more tahn one male

monogomy

1 male mates with 1 female

promiscuity

members of a group with more than 1 female and male mate with one another