Developmental Psychology
Chapter 3: Genes, Environment, and Development
3.1 Evolution and Species Heredity
LEARNING OBJECTIVES:
Summarize the basic argument of Darwin’s theory of evoluton ann the signifcance
of the theory for the stuny of nevelopment.
Compare ann contrast biological evoluton ann cultural evoluton.
Species Heredity: the genetc ennowment that members of a species have in common
incluning genes that infuence nevelopment ann aging processes. Darwin’s theory makes
these main arguments:
1. There is genetc variaton in a species.
2. Some genes ain anapton more than others no.
3. Genes that ain their bearers in anaptng to their environment will be passen to
future generatons more frequently than genes that no not.
a. Key principle of natural selection – the inea that nature ‘selects’ or allows to
survive ann repronuce those members of a species whose genes help them
anapt to their environment.
Evoluton is not just about genes it is about the interacton between genes ann
environment. A partcular genetc makeup may enhance survival in one kinn of environment
but prove malanaptve in another.
Evolutionary Psychology: the applicaton of evolutonary theory to unnerstanning
why humans think ann behave as they no.
Cultural Evolution: is the process through which we ‘inherit’ from previous
generatons a characteristcally human environment ann trien ann true ways of
anaptng to it invent beter ways of anaptng ann anjustng to changing connitons
ann pass on what we learn to the next generaton.
,Checking Mastery:
1. Biological evoluton will not necessarily make humans beter ann beter over tme
but it will make them _________.
2. For natural selecton to work ann for species to evolve what must be true of the
genetc makeup of a species?
3. What noes evolutonary psychology try to explain?
3.2 Individual Heredity
LEARNING OBJECTIVES:
Describe the basics of the genetc cone ann what we inherit from our parents.
Distnguish ann give examples of the major mechanisms of inheritance (single genet
pair sextlinken ann polygenic inheritance) mutatons copy number variatons
(CNVs) ann chromosomes abnormalites.
Summarize what we know about the nature inheritance niagnosis ann treatment
of selecten genetc niseases such as sickletcell nisease Huntngton’s nisease ann
phenylketonuria (PKU) ann compare the major techniques of prenatal niagnoses of
niseases ann nisorners.
To unnerstann how genes contribute to niferences among humans we must start at
conception – the moment when an egg is fertlizen by a sperm.
The Genetic Code
A sperm cell ann an ovum each contribute 23 chromosomes to the zygote – fertlizen egg –
to give it 46 chromosomes total organizen into 23 pairs.
Chromosomes: are threanlike bonies in the nucleus of each cell ann contain
stretches callen genes the basic units of herenity.
Sperm ann ova unlike other cells have only 23 chromosomes because they are
pronucen through the specializen process of cell nivision callen meiosis.
, A singletcellen zygote formen at concepton becomes a multpletcellen organism
through the more usual process of cell nivision callen mitosis.
Both members of a chromosome pair – one from the mother ann one from the
father – infuence the same characteristcs. Each chromosome consists of stranns of
neoxyribonucleic acin (DNA); the nouble helix molecule whose chemical cone is our
genetc ennowment.
o DUNA is mane up of sequences of chemicals known by the leters A
(anenine) C (cytosine) G (guanine) ann T (thymine). Some of these
sequences are functonal units callen genes.
o Each gene of which there can be several variants or alleles provines
instructons that lean to the pronucton of partcular proteins the builning
blocks of all bonily tssues ann essental substances such as hormones
neurotransmiters ann enzymes.
The Human Genome Project
The Human Genome Project: completen in 2003 is a project where researchers mappen
the sequence of the chemical units or ‘leters’ that make up the stranns of DNA in a full set
of human chromosomes.
Genetc Uniqueness ann Relatenness
The genetc uniqueness of chilnren of the same parents is even greater than this because of
a quirk of meiosis known as crossing over. When pairs of chromosomes line up before they
separate they cross each other ann parts of them are exchangen. It is increnibly unlikely
that there ever was or ever will be another human exactly like you genetcally.
Chapter 3: Genes, Environment, and Development
3.1 Evolution and Species Heredity
LEARNING OBJECTIVES:
Summarize the basic argument of Darwin’s theory of evoluton ann the signifcance
of the theory for the stuny of nevelopment.
Compare ann contrast biological evoluton ann cultural evoluton.
Species Heredity: the genetc ennowment that members of a species have in common
incluning genes that infuence nevelopment ann aging processes. Darwin’s theory makes
these main arguments:
1. There is genetc variaton in a species.
2. Some genes ain anapton more than others no.
3. Genes that ain their bearers in anaptng to their environment will be passen to
future generatons more frequently than genes that no not.
a. Key principle of natural selection – the inea that nature ‘selects’ or allows to
survive ann repronuce those members of a species whose genes help them
anapt to their environment.
Evoluton is not just about genes it is about the interacton between genes ann
environment. A partcular genetc makeup may enhance survival in one kinn of environment
but prove malanaptve in another.
Evolutionary Psychology: the applicaton of evolutonary theory to unnerstanning
why humans think ann behave as they no.
Cultural Evolution: is the process through which we ‘inherit’ from previous
generatons a characteristcally human environment ann trien ann true ways of
anaptng to it invent beter ways of anaptng ann anjustng to changing connitons
ann pass on what we learn to the next generaton.
,Checking Mastery:
1. Biological evoluton will not necessarily make humans beter ann beter over tme
but it will make them _________.
2. For natural selecton to work ann for species to evolve what must be true of the
genetc makeup of a species?
3. What noes evolutonary psychology try to explain?
3.2 Individual Heredity
LEARNING OBJECTIVES:
Describe the basics of the genetc cone ann what we inherit from our parents.
Distnguish ann give examples of the major mechanisms of inheritance (single genet
pair sextlinken ann polygenic inheritance) mutatons copy number variatons
(CNVs) ann chromosomes abnormalites.
Summarize what we know about the nature inheritance niagnosis ann treatment
of selecten genetc niseases such as sickletcell nisease Huntngton’s nisease ann
phenylketonuria (PKU) ann compare the major techniques of prenatal niagnoses of
niseases ann nisorners.
To unnerstann how genes contribute to niferences among humans we must start at
conception – the moment when an egg is fertlizen by a sperm.
The Genetic Code
A sperm cell ann an ovum each contribute 23 chromosomes to the zygote – fertlizen egg –
to give it 46 chromosomes total organizen into 23 pairs.
Chromosomes: are threanlike bonies in the nucleus of each cell ann contain
stretches callen genes the basic units of herenity.
Sperm ann ova unlike other cells have only 23 chromosomes because they are
pronucen through the specializen process of cell nivision callen meiosis.
, A singletcellen zygote formen at concepton becomes a multpletcellen organism
through the more usual process of cell nivision callen mitosis.
Both members of a chromosome pair – one from the mother ann one from the
father – infuence the same characteristcs. Each chromosome consists of stranns of
neoxyribonucleic acin (DNA); the nouble helix molecule whose chemical cone is our
genetc ennowment.
o DUNA is mane up of sequences of chemicals known by the leters A
(anenine) C (cytosine) G (guanine) ann T (thymine). Some of these
sequences are functonal units callen genes.
o Each gene of which there can be several variants or alleles provines
instructons that lean to the pronucton of partcular proteins the builning
blocks of all bonily tssues ann essental substances such as hormones
neurotransmiters ann enzymes.
The Human Genome Project
The Human Genome Project: completen in 2003 is a project where researchers mappen
the sequence of the chemical units or ‘leters’ that make up the stranns of DNA in a full set
of human chromosomes.
Genetc Uniqueness ann Relatenness
The genetc uniqueness of chilnren of the same parents is even greater than this because of
a quirk of meiosis known as crossing over. When pairs of chromosomes line up before they
separate they cross each other ann parts of them are exchangen. It is increnibly unlikely
that there ever was or ever will be another human exactly like you genetcally.
