Summary

These notes cover the origins of dichotomous thinking in psychology, exploring the nature versus nurture debate and the impact of brain damage on psychological functioning. They also touch on chimpanzee behavior and evolutionary biology, offering an overview of human evolution and animal behavior.

Full Transcript

Chapter 2 – evolution, genetic s and experience Origins of dichotomous thinking Is it physiological or psychological? - For history of western culture, whatever the truth is if the church say it true then only its true - In about 1400 things started to change with the plague, fam...

Chapter 2 – evolution, genetic s and experience Origins of dichotomous thinking Is it physiological or psychological? - For history of western culture, whatever the truth is if the church say it true then only its true - In about 1400 things started to change with the plague, famines and such - Rene Descartes (a philosopher 1596-1650) advocated a philosophy and gave one part of universe and other part to church Argued that universe has 2 elements Cartesian dualism a. Physical matter – behaves according to the law of nature and is a suitable obj for scientific investigation (even the brain and nonhuman animals were considered to be entirely physical b. Human mind (soul, self, spirit) – lacks physical substance, controls human behavior and obeys no natural laws and is appropriate purview of the church Cartesian dualism was sanctioned by the roman church so the idea of human brain and mind are separate became more widely accepted Is it inherited or learned? - nature-nurture issue – debate on whether humans and other animals inherit their behavioral capacities or acquire through learning - John B Watson (nurture) say there is no evidence of inheritance of behavioral traits - Ethology (nature) Problems with thinking about the biology of behavior in terms of traditional dichotomies Problem 1: Brain damage impacts psychological functioning Example: Asomatognosia (the man who fell out of his bed) - Lack awareness of parts of ones own body - Damage to the right frontal and parietal lobe Problem 2: Chimps show psychological human abilities - Self awareness psychological complexity - The chimps groom and inspects itself using the mirror's reflection - The chimps examine and touch the red marks that is viewable in mirror Nature and nurture thinking runs into difficulty - Factors other than genetics and learning were shown to influence behavioral development (factors= fetal environment, nutrition, stress and sensory stimulation) - Nurture encompasses both learning and environment - Genetic factors or learning to genetics factors or experience - Genetic and experiential factors interact (interactionism) Model of Biology of Behavior - All behavior is the product of interactions among three factors 1. The organism's genetic endowment 2. Experience 3. Perception of current situation HUMAN EVOLUTION - Modern biology began in 1859 with the publication of Charles Darwin’s On The Origin of Species - Darwin suggested evolution (though he was not the first one to suggest that species evolve) - He presented 3 kinds of evidence a. Documented the evolution of fossil records b. Described striking structural similarities among living species c. Major changes brought in domestic plants and animals by programs of selective breeding - Darwin argued and say that evolution occurred through natural selection Members of each species vary greatly in their structure, physiological and behavior (heritable traits associated with high rates of survival and reproduction is most likely to be passed on to future generations ) - Fitness – the ability on an organism to survive and contribute its genes to the next generation EVOLUTION AND BEHAVIOR Obvious role in evolution - Ability to find food - Avoid predation - Defend one's young Less obvious but no less important - Social dominance Males establish a stable hierarchy of social dominance through combative encounters with other males Some physical damage, some posturing and threatening until one of the two combatants back down Once hierarchy is established, lower ranking males learn to avoid and submit to more dominant males Why social dominance is an important factor in evolution? a. Because dominant males copulate more than non dominant males and are more effective in passing on their characteristics to future generations b. high ranking female chimpanzees more likely maintain access to productive forging areas - Courtship displays a. Male approach female, signal interest (either through olfactory, visual, auditory or tactual). Then might elicit a response in the female and get another response back from the male and it continues till copulation ensues b. If one fails to react, copulation might not occur c. Species – group of organisms that reproductively isolate from other organisms d. Conspecifics – members of the same species COURSE OF HUMAN EVOLUTION Evolution of vertebrates - Complex multicellular water dwelling organisms first appeared on earth about 800 million years ago - 250 million years later chordates (animals with dorsal nerve cords) evolved. (dorsal cord – nerves that run along the middle of the back) - 1 of the 40 (phyla) - First chordates with spinal bones to protect the dorsal nerve cords evolved 25 million years later - Spinal bone is known as vertebrae - First vertebrates = primitive bony fishes - Now got 7 classes of vertebrates, 3 classes of fish + amphibians, reptiles, birds and mammals Evolution of amphibians - 410 million years ago bony fishes start to venture out of the water - Fishes that survive briefly on land had 2 advantages, a. Can escape stagnant pools b. Take advantage of terrestrial food sources - Through natural selection process, fins and gills of bony fishes transformed into legs and lungs and that’s how the 1st amphibians evolved 370 million years ago - Amphibians in larval form must live in water. Only the adults can survive on land Evolution of reptile - 315 million years ago reptiles evolved from branch of amphibians - Were the first vertebrates to lay shell covered eggs and covered by dry scales - The 2 adaptions reduced the reliance of reptiles on watery habitat - 1st stage of life it spends time on watery habitat then - once hatched it will live far from water because dry scales reduce water loss through its water permeable skin Evolution of mammals - 225 million years ago new class of vertebrates evolved from small reptile line - Females feed their young with secretions of mammary glands - Females nurture the young in the watery environment within their body until mature to be born - Duck billed platypus is one surviving egg laying mammal - there's 26 different orders of mammals (we belong to primates) - human order is named in Latin primus which is first or foremost - there’s 16 groups of primates - Apes (gibbons, OU, gorillas and chimps) thought to have evolved from old world monkeys - Apes can walk upright straight for short distances not like OWM but got long arms and grasping hind feet’s specialized for treetop travel Emergence of humankind - Humans known as hominins - Include 6 subgroups including Australopithecus and Homo - Homo is thought to be composed of at least eight species ; seven of which now are extinct - First homo species emerged from Australopithecus 4 million years ago - Homo sapiens emerged 275 000 years ago - Australopithecus were only about 1.3 meters tall Small brains Pelvis and leg bone indicate they were upright - Distinctive features of Homo Size of brain cavity larger that Australopithecus but smaller than modern human Kingdom - animals Phylum - chordate Class - mammal Order - primate Family - Hominid Tribe - Hominin Genus - Homo Species - sapiens THINKING ABOUT HUMAN EVOLUTION - Evolution does not proceed in a single line - Humans have little reason to claim evolutionary supremacy ( because we only existed for a brief period) - Evolution does not always proceed slowly. Rapid changes can be triggered by sudden changes in environment - Fewer than 1% of all known species are still in existence - Evolution does not progress to preordained perfection - Not all existing behaviors or structures are adaptive. Incidental non adaptive evolutionary by products (spandrels) can be adaptive then be non adaptive (human belly button) - Not all existing adaptive characteristics evolved to perform from their current function - Exaptation – evolved to serve only one function and were later co opted to serve another (like bird wings, the limbs were initially evolved for walking) - Homologous – structure that are similar among species - Analogous – structure that are similar but have different evolutionary origin - Convergent – evolution of different species but uses the same solution as demanded by the environment EVOLUTION OF HUMAN BRAIN - There is no clear relationship between overall brain size and intelligence (avg human brain 1000 – 2000 g) - Brains size (cerebrum) increase during evolution - Increase number of convolutions (folds on cerebral surface) has greatly increased the surface area of cerebral cortex UNDERSTANDING MATE BONDING - Most mate bond promiscuously - Most mammals forms polygynous mating bonds - Polyandry – males contribute to reproduction more than females - Humans generally form monogamous bond (one on one) - Mate bonding in humans is predicted through evolutionary theory Men value youth and attractiveness Women value power and earning capacity Physically attractive women bond with men with high status Mate attraction (F= physical attraction) (M= display power and resources) Men more likely than women to commit adultery FUNDAMENTAL GENETICS Mendelian genetics - Dichotomous traits – occur in one form or another but never in combination - True breeding lines – breeding lines where the interbred members always produce offspring with the same trait generation after generation Dominant trait – appeared in all first generation offspring Recessive trait – appeared in about one quarter of the second generation offspring Phenotype – organism’s observable trait Genotype – traits passed on through its genetic material Homozygous – identical alleles (BB) Heterozygous – different alleles (Bw) CHROMOSOMES - Genes are in chromosomes - Humans have 23 pairs of chromosomes with an allele on each chromosome - Meiosis (produce gametes) – the chromosome s divide and one of each pair goes to each of the two gametes that result from cell division - First stage, chromosome lines up pairs - Then cross over one another forming a linkage and break apart to exchange sections - As a result of genetic recombination each of the gametes that formed zygote contains chromosomes that are unique, spliced together recombinations of chromosomes from parents - After meiosis, mitosis occurs - The no. of chromosomes double up so that both daughter cells end up with full complement of chromosomes (23 pairs) STRUCTURE AND REPLICATION - Each chromosome is a double stranded molecule DNA - Each strand is a sequence of nucleotide bases attached to phosphate and deoxyribose - 4 nucleotide base – Adenine, Cytosine, Guanine, Thymine - Each has genetic codes - Coiled and bonded together by the attraction of A for T and C for G (complementary sequence) - Replication – critical process of DNA molecule Two strands unwind Then exposed nucleotide bases on each strand attract their complementary bases which are floating in the fluid of nucleus - Clinical consequences of chromosome replication – down syndrome (extra chromosome) mutation – alterations of individual genes SEX CHROMOSOME AND SEX LINKED TRAITS - autosomal chromosome – matched pair chromosome (one exception is pair of sex chromosome) - Sex chromosome – X and Y F = XX M= XY - Sex linked traits – trait influenced by genes on the sex chromosome - Dominant traits on the X will be seen more in females - Recessive traits seen more in males - Color blindness is quite rare in female - Male who possesses one color blindness gene is color blind GENETIC CODE AND GENE EXPRESSION - Promoters – stretches of DNA wose function is to determine whether or not particular structural gene are converted into proteins through a two phase process known as gene expression - Activators – protein that binds to DNA and increase gene expression - Repressors – binds to DNA and decrease gene expression - Gene expression got 2 phase - 1st phase = transcription Chromosome contain gene unravels The unraveled section serves as a template to transcript a short strand of RNA (contains nucleotide base uracil instead of thymine and phosphate and ribose backbone instead of a phosphate and deoxyribose backbone) mRNA is synthesized from the DNA transcription mRNA leave nucleus and 2nd phase translation occurs mRNA attach to any of the many ribosomes present in the cell’s cytoplasm Ribosomes move along mRNA strand and translates the genetic code Codon – 3 consecutive nucleotide bases along the mRNA strand Each codon will instruct ribosome to add 1 of the 20 different kinds of amino acids to the protein it is constructing Each kind of amino acid is carried to the ribosome by molecules of tRNA As ribosome reads a codon, it attracts a tRNA This continues until it reaches a codon that that tells it the protein is complete Completed protein is released into cytoplasm - Epigenetics – patterns of gene expression appear to be heritable Human genome project - Purpose is to compile a map of the sequence of all 3 billion nucleotides bases that compose human chromosomes - Protein encoding genes constitute only about 1% of human DNA - Human proteome – a nearly complete map of the entire set of proteins encoded for by our genes - Gene research focused on complex interactions between genes, their variants, and experience Modern genetics growth pf epigenetics - Epigenetics – study of all mechanism of inheritance other than those mediated by changes to the gene sequence of DNA - Four factors that led to the rise of epigenetics HGP generated an arsenal of new research techniques Protein coding genes constitute only about 1% of human DNA Protein encoding is only a minor function of RNA Mechanism of gene experience interaction is unknown - 5 important advances in epigenetics Non gene DNA is no longer accepted Variety different types of small RNA molecules Gene expression can be regulated by a. DNA methylation – reaction occurs when a methyl group attaches to a DNA molecule usually at the cytosine sites in mammals b. Histone remodeling – reaction that occurs when histones (protein around coiled DNA) change their shape that would influence the shape of the adjacent DNA (it can either decrease of increase expression) RNA editing – epigenetic effects that regulate gene expression by acting on messenger RNA rather than genes Epigenetics mechanisms can be enduring a. Epigenetic changes can be induced by particular experiences such as neural activity, hormonal state, changes to the environment that can last a lifetime b. Transgenerational epigenetics – examines the transmission of experiences via epigenetic mechanisms across generations EPIGENETICS ON BEHAVIORAL DEVELOPMENT: INTERACTION OF GENETIC FACTORS AND EXPERIENCE 1. Selective breeding of maze bright and maze dull rats - Tyron first start to train the heterogeneous to run in a complex maze and when they reach the goal box, they will be rewarded with food - Then he mated the females and males that least frequently entered incorrect alleys during training as maze bright - He bred the females and males that most frequently entered the correct alleys as the maze dull - The selective breeding procedure carried on for 21 generations - Tryon used cross fostering control procedure where he tested the maze bright offspring that is reared by maze dull parents and maze dull offspring with maze bright parents - The maze bright made few errors even when reared by maze dull parents - The maze dull offspring made many errors even when its reared by maze bright parents - Selective breeding based on one behavioral trait usually brings a host of other behavioral traits along with it a. Impoverished environment (a baren wire mesh group cage) b. Enriched environment (wire mesh group cage that has tunnels, ramps, visual displays and other objects to stimulate interest) - When maze dull reached maturity they made significantly more errors than the maze bright only if they had been reared in the impoverished environment 2. Phenylketonuria: a single metabolic disorder - Symptoms – vomiting, seizures, hyperactivity, irritability and brain damage - Because the gene is recessive it only develops in homozygous individuals - PKU homozygotes lack of phenylalanine hydroxylase (enzyme needed to convert phenylalanine to tyrosine) - As results levels of dopamine, neurotransmitter normally synthesized by tyrosine is low - Will cause abnormal brain development - Phenylalanine restricted diet – if a baby born and has hig levels of phenylalanine, they will be placed under the phenylalanine restricted diet This diet will reduce the amount of phenylalanine in blood and development of intellectual disability 3. Development of bird song a. Sensory phase Begins several days after hatching They form memories of adult songs they hear that late guide the development of their own singing Males who do not hear songs of their own species may later develop a song but it is likely to be abnormal b. Sensorimotor Juvenile male birds twitter subsongs Rambling vocalizations of sub songs gradually refined until they resemble the songs of their adult tutor Auditory feedback is necessary for the development of singing unless the young birds are able to hear themselves sing and their sub songs do not develop into adult songs - Most songbird species are age limited learners (once the sound is crystallized it remains unchanged - Open ended learners – able to add new songs to their repertoire throughout their lives

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