Psychology
Chapter 3: Genetics and Evolutionary Foundations of
Behavior
Textbook: Psychology (8th Edition) by Peter Gray & David F. Bjorklund
Vocabulary:
Evolution: the long term adaptive process, spanning generations, that equips each species for life in its
ever changing environment
DNA: (deoxyribonucleic acid) double helix strands linked by 4 bases: adenine & thymine, cytosine &
guanine. Genetic codes that make all the proteins in our bodies.
Genes: basic unit of heredity passed from the parents to the child
RNA: (ribonucleic acid) which reads information in the gene and is a template to assemble proteins
Genotype: genes that the individual inherits
Phenotype: observable properties of the body and behavioral traits
PKU: (phenylketonuria) lacking enzymes to metabolize phenylpyruvic acid leads to brain damage
Homologies: any similarity that exists because of the species common ancestry (in DNA structures and
enzymes)
Non-verbal communication: communicating without vocal communications (e.g. facial expressions or
a peacock revealing their feathers to attract a mate)
Biological Preparedness: behaviors that were biologically inherited to develop associations between
stimuli and responses (e.g. walking or talking)
Parental Investment: caring for the ospring will increase the ospring’s survival rate and the parents
ability to invest in another ospring
Functionalism: the attempt to explain behavior in terms of what it accomplishes for the behaving
individual
Distal Explanations: explanations at the evolutionary level. Statements that the behavior has played a
role in the species survival and reproduction over evolutionary time. How the behaviors have helped
ancestors genes to make it to the next generations (can also be called ultimate causation)
Proximate Explanations: explanations that deal with mechanisms. Statements of immediate conditions;
both inside and out the species that evoke the behavior.
Vestigial Explanations: traits that were benecial to our ancestors but aren’t functional today but they
still remain in our genes
Genetic Determinism: belief that genes determine behavior is independent of experience
Analogy: any similarity that stems from convergent evolution (when dierent species, because of
similarity in their lifestyles, independently evolve a common characteristic)
, Promiscuity: having/involving many sexual partners
Altruism: an individual helps another while decreasing its own survival or reproduction capacity
Cells and Chromosomes
Living creatures made of cells: water-lled compartment + solutes and organelles; partially permeable
membrane
- inner compartment (nucleus) —> chromosomes from mother and father
- mitochondrion (organelle); only maternal chromosomes
- human chromosomes —> 23 pairs
- normal amount of chromosomes are 22 pairs and the 23rd pair determines gender
Chromosome: DNA chain
Girl chromosomes- XX
Male chromosomes- XY
Sexual Reproduction and Twins:
- sperm (male) + ovaries (female) formed by meiosis to create a zygote
- both have 23 chromosomes when they form together they form one cell
- the zygote replicates itself by mitosis (cells split into two identical cells)
- both parents chromosomes can create 4 dierent possibilities (genders) —> chances of male &
female from both parent
- sexual reproduction is not reproducing you, it’s creating a genetically unique individual with
half of each parent’s genes, each zygote is unique
Zygote: formation of a sperm cell and a ovary
Identical twins: identical genes but same zygote, same zygote but then splits to another cell with the
same DNA
- same genotype, phenotypes may dier due to dierent lives of twins that can aect their
personal body growth
Fraternal twins: separate zygotes, separate mitosis, dierence in DNA but still twins (dierent
chromosomes or RNA)
Sexual Reproduction: Mating Behaviors
Polygyny: a male who gets a group of females to only mate with
Polyandry: a female who mates with a group of males
Monogamy: a female and male only mate with each other
Polygynandry: any male or female can mate with each other
Chapter 3: Genetics and Evolutionary Foundations of
Behavior
Textbook: Psychology (8th Edition) by Peter Gray & David F. Bjorklund
Vocabulary:
Evolution: the long term adaptive process, spanning generations, that equips each species for life in its
ever changing environment
DNA: (deoxyribonucleic acid) double helix strands linked by 4 bases: adenine & thymine, cytosine &
guanine. Genetic codes that make all the proteins in our bodies.
Genes: basic unit of heredity passed from the parents to the child
RNA: (ribonucleic acid) which reads information in the gene and is a template to assemble proteins
Genotype: genes that the individual inherits
Phenotype: observable properties of the body and behavioral traits
PKU: (phenylketonuria) lacking enzymes to metabolize phenylpyruvic acid leads to brain damage
Homologies: any similarity that exists because of the species common ancestry (in DNA structures and
enzymes)
Non-verbal communication: communicating without vocal communications (e.g. facial expressions or
a peacock revealing their feathers to attract a mate)
Biological Preparedness: behaviors that were biologically inherited to develop associations between
stimuli and responses (e.g. walking or talking)
Parental Investment: caring for the ospring will increase the ospring’s survival rate and the parents
ability to invest in another ospring
Functionalism: the attempt to explain behavior in terms of what it accomplishes for the behaving
individual
Distal Explanations: explanations at the evolutionary level. Statements that the behavior has played a
role in the species survival and reproduction over evolutionary time. How the behaviors have helped
ancestors genes to make it to the next generations (can also be called ultimate causation)
Proximate Explanations: explanations that deal with mechanisms. Statements of immediate conditions;
both inside and out the species that evoke the behavior.
Vestigial Explanations: traits that were benecial to our ancestors but aren’t functional today but they
still remain in our genes
Genetic Determinism: belief that genes determine behavior is independent of experience
Analogy: any similarity that stems from convergent evolution (when dierent species, because of
similarity in their lifestyles, independently evolve a common characteristic)
, Promiscuity: having/involving many sexual partners
Altruism: an individual helps another while decreasing its own survival or reproduction capacity
Cells and Chromosomes
Living creatures made of cells: water-lled compartment + solutes and organelles; partially permeable
membrane
- inner compartment (nucleus) —> chromosomes from mother and father
- mitochondrion (organelle); only maternal chromosomes
- human chromosomes —> 23 pairs
- normal amount of chromosomes are 22 pairs and the 23rd pair determines gender
Chromosome: DNA chain
Girl chromosomes- XX
Male chromosomes- XY
Sexual Reproduction and Twins:
- sperm (male) + ovaries (female) formed by meiosis to create a zygote
- both have 23 chromosomes when they form together they form one cell
- the zygote replicates itself by mitosis (cells split into two identical cells)
- both parents chromosomes can create 4 dierent possibilities (genders) —> chances of male &
female from both parent
- sexual reproduction is not reproducing you, it’s creating a genetically unique individual with
half of each parent’s genes, each zygote is unique
Zygote: formation of a sperm cell and a ovary
Identical twins: identical genes but same zygote, same zygote but then splits to another cell with the
same DNA
- same genotype, phenotypes may dier due to dierent lives of twins that can aect their
personal body growth
Fraternal twins: separate zygotes, separate mitosis, dierence in DNA but still twins (dierent
chromosomes or RNA)
Sexual Reproduction: Mating Behaviors
Polygyny: a male who gets a group of females to only mate with
Polyandry: a female who mates with a group of males
Monogamy: a female and male only mate with each other
Polygynandry: any male or female can mate with each other
