EVOLUTION, EVOLUTION, HEREDITY, AND HEREDITY, AND BEHAVIORBEHAVIOR

TO MANTO MAN

FROMFROMMONKEYMONKEY

DARWIN AND EVOLUTIONDARWIN AND EVOLUTION Biological evolution-Biological evolution- changes that take place in the genetic changes that take place in the genetic

and physical characteristics of a population overtimeand physical characteristics of a population overtime Adaptive significanceAdaptive significance-Its effectiveness in aiding the -Its effectiveness in aiding the

organism to adapt to changing environmental conditions (organism to adapt to changing environmental conditions (Ex.-Ex.-gregariousness-tendency to form groups)gregariousness-tendency to form groups)

Ultimate causesUltimate causes-Events and conditions over successive -Events and conditions over successive generations that have slowly shaped the behavior of our generations that have slowly shaped the behavior of our speciesspecies

Proximate causesProximate causes-Immediate environmental variables that -Immediate environmental variables that affect behavioraffect behavior

Artificial selectionArtificial selection-A procedure in which particular animals -A procedure in which particular animals are mated to produce offspring who possess desirable are mated to produce offspring who possess desirable characteristics.characteristics.

Natural selectionNatural selection-Competition amongst animals, those with -Competition amongst animals, those with best-adapted traits survivebest-adapted traits survive

Evolutionary PsychologyEvolutionary Psychology

Investigates how an organism’s evolutionary Investigates how an organism’s evolutionary history contributes to the development of history contributes to the development of behavior patterns and cognitive strategies behavior patterns and cognitive strategies related to reproduction and survival in its related to reproduction and survival in its lifetimelifetime

May help psychologists understand how May help psychologists understand how evolution and development influence evolution and development influence culture culture ((sum of socially transmitted knowledge, sum of socially transmitted knowledge, customs, and behavior patterns common to a customs, and behavior patterns common to a particular group)particular group)

NaturalNatural Selection and Selection and Evolution – Premises for Evolution – Premises for

EvolutionEvolution

1.1. The world’s animal & plant communities change over The world’s animal & plant communities change over time with new forms originating and others becoming time with new forms originating and others becoming extinctextinct

2.2. Evolutionary process is gradual and continual. New Evolutionary process is gradual and continual. New species arise through slow and steady environmental species arise through slow and steady environmental changes that gradually ‘perfect’ each species to its changes that gradually ‘perfect’ each species to its surroundings. Sudden, dramatic changes in surroundings. Sudden, dramatic changes in environment challenges species ability to adapt.environment challenges species ability to adapt.

3.3. All organisms descended from an original & common All organisms descended from an original & common ancestor.Over time, the process of natural selection ancestor.Over time, the process of natural selection has created different species, each adapted to its has created different species, each adapted to its ecological nicheecological niche

AND FINALLY…AND FINALLY…

4. 4. Natural selection not only Natural selection not only causes changes within a population causes changes within a population during changing environmental during changing environmental conditions; it also maintains the conditions; it also maintains the status quo under relatively status quo under relatively constant environmental conditions.constant environmental conditions.

REPRODUCTIVE SUCCESSREPRODUCTIVE SUCCESS

The number of viable The number of viable offspring it produces relative offspring it produces relative

to the number of viable to the number of viable offspring produced by other offspring produced by other

members of the speciesmembers of the species

***Survival of the fittest does ***Survival of the fittest does NOT always mean survival of NOT always mean survival of

the most physically fit or the most physically fit or strongest, but depends on strongest, but depends on

reproductive successreproductive success

Two Aspects of Natural Two Aspects of Natural SelectionSelection

1.1. Variation-Variation-Differences among members of Differences among members of a species a species

GenotypeGenotype-genetic make-up,everyone’s -genetic make-up,everyone’s

different.determines how much different.determines how much environment can influence development environment can influence development and behaviorand behaviorPhenotypePhenotype-Characteristics and behaviors -Characteristics and behaviors produced by interaction of genotype in produced by interaction of genotype in environment (intelligence) environment (intelligence)

FACTORS

Competition-Competition-Organisms will Organisms will compete for food, territory, and compete for food, territory, and mates to survivemates to survive

Natural Selection in Natural Selection in Human EvolutionHuman Evolution

Gorillas and Chimps-closest living Gorillas and Chimps-closest living relativerelative

Human species began 2 million Human species began 2 million years agoyears ago

Homo-habilis “handyman”-1Homo-habilis “handyman”-1stst human,1.3meters tall,40kg,could human,1.3meters tall,40kg,could walk upright and make toolswalk upright and make tools

•Homo-erectus “upright man”-larger Homo-erectus “upright man”-larger brain, discovered fire, made base brain, discovered fire, made base

campscamps

HOMO-SAPIENS HOMO-SAPIENS “INTELLIGENT MAN”“INTELLIGENT MAN”500,000 years ago,skilled 500,000 years ago,skilled

toolmakers and clothiers, had toolmakers and clothiers, had cultural rituals,used fire for cooking, cultural rituals,used fire for cooking,

warmth and protection warmth and protection

Natural Selection Favored Natural Selection Favored 2 characteristics2 characteristics

1.1. BipedalismBipedalism-walking on 2 -walking on 2 feet,greater mobilityfeet,greater mobility

2.2. EncephalizationEncephalization-Increased brain -Increased brain size>thinking,reasoning,decision size>thinking,reasoning,decision making,greater reproductive making,greater reproductive successsuccess

HEREDITY AND GENETICSHEREDITY AND GENETICS

GeneticsGenetics-The study of the structure -The study of the structure and function of genes and how they are and function of genes and how they are passed along from one generation to passed along from one generation to the next,how genetic makeup influences the next,how genetic makeup influences physical and behavioral characteristicsphysical and behavioral characteristics

HeredityHeredity-sum of traits and tendencies -sum of traits and tendencies inherited from parents and other inherited from parents and other ancestorsancestors

Basic Principles of Basic Principles of GeneticsGenetics

DNA(deoxyribonucleic acid)DNA(deoxyribonucleic acid)-strands -strands of sugar and phosphate connected by of sugar and phosphate connected by nucleotide molecules of nucleotide molecules of adenine,thymine,guanine,&cytosineadenine,thymine,guanine,&cytosine

GenesGenes- ‘Recipes for Protein Synthesis’ - ‘Recipes for Protein Synthesis’ Each nucleotide specifies and particular Each nucleotide specifies and particular amino acid that has instructions for amino acid that has instructions for synthesization,causing trait to synthesization,causing trait to appear<faulty genes can cause serious appear<faulty genes can cause serious physiological and behavioral problems>physiological and behavioral problems>

Chromosomes and MeiosisChromosomes and Meiosis

Genes are located on Genes are located on chromosomeschromosomes--rod-like structures made of DNA rod-like structures made of DNA found in the nucleus of every cellfound in the nucleus of every cell

Each set contains a different Each set contains a different sequence of genes (23 from each sequence of genes (23 from each parent)parent)

Sex ChromosomesSex Chromosomes-contain -contain instructions for development of male instructions for development of male or female characteristicsor female characteristics

SEX SELLS (I MEAN CELLS) SEX SELLS (I MEAN CELLS) form through MEIOSISform through MEIOSIS

23 pairs of chromosomes break apart into 2 23 pairs of chromosomes break apart into 2 groups, one member of each pair joining a group. groups, one member of each pair joining a group.

The cell splits into 2 cells, each containing 23 The cell splits into 2 cells, each containing 23 indiv. Chromosomes indiv. Chromosomes

The assignment of members of each chromosome The assignment of members of each chromosome is randomis random

A SINGLE individual can produce 8,388,608 A SINGLE individual can produce 8,388,608 different ova or spermdifferent ova or sperm

Union of ova and sperm also random, a couple can Union of ova and sperm also random, a couple can produce 70,368,774,177,664 different childrenproduce 70,368,774,177,664 different children

2323rdrd pair-sex chromosomes XX-female, XY pair-sex chromosomes XX-female, XY--male, male, sperm determines sex.sperm determines sex.

DOMINANT AND DOMINANT AND RECESSIVE ALLELESRECESSIVE ALLELES

AlleleAllele-alternative forms of the same -alternative forms of the same genegene

HomozygousHomozygous-both parents contribute -both parents contribute same allelesame allele

HeterozygousHeterozygous-parents contribute -parents contribute different allelesdifferent alleles

Dominant alleleDominant allele-more powerful -more powerful influence on expression of traitinfluence on expression of trait

Recessive alleleRecessive allele-not expressed unless -not expressed unless both alleles are recessiveboth alleles are recessive

Influences of Gender on Influences of Gender on HeredityHeredity

Sex-linked genesSex-linked genes-only carried on -only carried on X chromosomeX chromosome

Ex)hemophelia-carried as Ex)hemophelia-carried as recessive gene only on X, females recessive gene only on X, females need both recessive chromosomes need both recessive chromosomes to inherit it and males only need to inherit it and males only need oneone

Mutations and Mutations and Chromosomal AberrationsChromosomal Aberrations

MutationMutation-accidental alteration to DNA code -accidental alteration to DNA code within a single genewithin a single gene

*original source of genetic diversity*original source of genetic diversity*most harmful, though some beneficial*most harmful, though some beneficial*can occur naturally or because of human *can occur naturally or because of human factors (radiation)factors (radiation)

Chromosomal aberrationChromosomal aberration-changes in parts -changes in parts of chromosomes or total # of chromosomesof chromosomes or total # of chromosomes*Ex)Partial deletion of chromosome 5 causes *Ex)Partial deletion of chromosome 5 causes cri-du-chatcri-du-chat

Genetic DisordersGenetic Disorders

Down SyndromeDown Syndrome-Chromosomal -Chromosomal aberration-extra chromosome 21aberration-extra chromosome 21*15% die before 1*15% die before 1stst b-day b-day*> chance, the older the mother is*> chance, the older the mother is*Not hereditary*Not hereditary

Huntington’s ChoreaHuntington’s Chorea-caused by -caused by dominate lethal gene, results in dominate lethal gene, results in degeneration of certain parts of the degeneration of certain parts of the brainsbrains*Emerges between ages 30 and 40*Emerges between ages 30 and 40

Genetic Disorders (cont.)Genetic Disorders (cont.)

Phenylketonuria(PKU)Phenylketonuria(PKU)--caused caused by a homozygous recessive gene. by a homozygous recessive gene. They are unable to breakdown They are unable to breakdown phenylalanine.phenylalanine.

*High levels of phenylalanine in *High levels of phenylalanine in blood causes severe brain damage blood causes severe brain damage and mental retardation.and mental retardation.

*Infants routinely tested*Infants routinely tested

Genetic CounselingGenetic Counseling

The process of determining the The process of determining the likelihood that a couple may produce likelihood that a couple may produce a child having a genetic disordera child having a genetic disorder*pedigree analysis to identify *pedigree analysis to identify relatives with genetic disordersrelatives with genetic disorders*Amniocentesis-fetus can be tested *Amniocentesis-fetus can be tested for genetic disorders by removing for genetic disorders by removing and examining fetal cells in amniotic and examining fetal cells in amniotic fluidfluid

Heredity and Behavior Heredity and Behavior GeneticsGenetics

HeritabilityHeritability-Statistical term that -Statistical term that refers to the amount of variability refers to the amount of variability in a trait in a given population, not in a trait in a given population, not inheritanceinheritance

Behavior GeneticsBehavior Genetics--Scientific Scientific study of heritability of the effects study of heritability of the effects of genetic influence on behaviorof genetic influence on behavior

Studying Genetic Influence Studying Genetic Influence using Artificial Selectionusing Artificial Selection

Any heritable trait can be selected Any heritable trait can be selected in a breeding program in a breeding program Ex)aggression, preference for Ex)aggression, preference for alcohol,mating behaviorsalcohol,mating behaviors

Bred smart mice together-had Bred smart mice together-had smart babies, however smart babies, however environment does affect environment does affect expression of genetic traitsexpression of genetic traits

Twin Studies and Genetic Twin Studies and Genetic InfluenceInfluence

Most powerful weapon in study of Most powerful weapon in study of human geneticshuman genetics

Unethical to manipulate people’s Unethical to manipulate people’s genetic history or restricting genetic history or restricting environmentenvironment

MonozygoticMonozygotic-single fertilized ovum-single fertilized ovum DizygoticDizygotic-fertilization of 2 separate -fertilization of 2 separate

ovaova

Twin Studies and Twin Studies and Concordance ResearchConcordance Research

Examines degree of similarity in traits Examines degree of similarity in traits expressed between twinsexpressed between twins

If one observes High concordance in If one observes High concordance in MZ twins & low in DZ twins can MZ twins & low in DZ twins can conclude it’s geneticconclude it’s genetic*Concluded genetics affect language, *Concluded genetics affect language, math, and vocabulary skills, personality math, and vocabulary skills, personality traits, emotional stability, and traits, emotional stability, and psychological disorderspsychological disorders*Blood type 100% heritability*Blood type 100% heritability

Strategies for Mating and Strategies for Mating and Rearing OffspringRearing Offspring

MonogamyMonogamy-mating of 1-mating of 1Female and 1 male (most Female and 1 male (most popular not most practiced)popular not most practiced) PolygynyPolygyny-1 male mating with >1 -1 male mating with >1

female (most common)female (most common) PolyandryPolyandry-1 female >1 male (rare)-1 female >1 male (rare) PolygynandryPolygynandry-Many males and -Many males and

many females (Chimps)many females (Chimps)

Parental InvestmentParental Investment

Time, Phys. Effort, and risks to life involved in Time, Phys. Effort, and risks to life involved in procreation and in feeding, nurturing and procreation and in feeding, nurturing and protecting offspringprotecting offspring

*critical factor in mate selection*critical factor in mate selection

*one willing to have greater investment is a *one willing to have greater investment is a more sought after matemore sought after mate

Competition for mates leads to Competition for mates leads to Sexual Sexual selectionselection-selection for traits specific to sex -selection for traits specific to sex such as body size or behaviorsuch as body size or behavior

Biological Basis for Biological Basis for AltruismAltruism

AltruismAltruism-unselfish concern of one indiv. -unselfish concern of one indiv. For the welfare of anotherFor the welfare of another

Kin selectionKin selection-biological favoritism -biological favoritism towards relativestowards relatives

Inclusive fitnessInclusive fitness-Reproductive success of -Reproductive success of those who share same genesthose who share same genes

*Indiv. Behave altruistically towards those that *Indiv. Behave altruistically towards those that share genetic history, and relatives surviveshare genetic history, and relatives survive

AND…AND…

Reciprocal altruismReciprocal altruism-Behaving -Behaving altruistically towards someone altruistically towards someone because you believe the act will be because you believe the act will be reciprocated to you or your kinreciprocated to you or your kin

THAT’STHAT’SALLALL

FOLKSFOLKS