Evolutionary Psychology - Lecture 2: Nature and Nurture Flashcards
Biology from a psychological point of view and general significance
Shapes views on nature vs nurture debate and position on other things such as academic, political and social implications -> gender, differences in sexual orientation, intelligence, race and aggression
Is Biology destiny?
No - need to understand that genes’ effects are mediated by environment
Genotype
What is inherited
Broad - The set of DNA molecules contained in nucleus
Personalised - A genotype particular to a trait
Phenotype
What develops
An organisms physiology, anatomy, behaviour
Breakdown of DNA
Body -> Cell -> Nucleus -> Chromosomes - 22 autosomes and 1 sex chromosome - DNA organised into 23 sets of chromosomes - 1 part of each set from each parent -> DNA -> DNA Sequence - ATCG -> this is what is analysed
Chromosome
Thread-like structures contained in the cell nucleus. Each chromosome is a DNA molecule. Chromosomes occur in pairs. Human somatic cells usually contain 23 pairs
Gene
A stretch of DNA that produces a specific protein
Allele
Alternative forms of gene at same locus (position of gene on chromosome)
Homozygous
When an organism possesses 2 identical alleles for a particular trait
Heterzygous
When an organism possesses 2 different alleles for a particular trait
Dominant
An allele that manifests it effects in both homozygotes and heterozygotes
Recessive
An allele that manifests it effects in only homozygotes
Polygenic inheritance
A trait whose phenotypic expression is influenced by many genes e.g. most psychological traits
Who founded PKU and experiment he did?
Asbjorn Folling did a urine test and found increased levels of PKU led to severe mental retardation
Full form of PKU
Phenylketonuria
What is PKU
“Inborn” metabolic disorder - causes vomiting, seizures, hyperactivity, retardation
How many white infants in USA does PKU affect?
1/10,000
What causes PKU?
Single recessive gene on chromosome 12
Normal pathway of phenylalanine
Enzyme phenylalanine hydroxylase (PAH) -> tyrosine
PKU pathway of phenylalanine
No enzyme -> Phenylpyruvate
What does phenylpyruvate do?
It is toxic to developing nervous system
Side effects of PKU
Blood levels of phenylalanine elevated
Prefrontal lobe damage
What can diet do in terms of PKU (Herzberg & Diamond 1993)?
Can intervene in effects of PKU by changing environment -> nature and nurture act together
Early application of diet reduces, but does not eliminate, cognitive deficits
Diets very hard to comply with “a diet devoid of meat, fish, dairy products, breads, nuts, and many other foods. Keeping this diet is difficult and PKU children must take a food additive in order to get enough protein”