Genetics & Evolutionary Genetics & Evolutionary PsychologyPsychology
Or:
Once more with Genetics
BasicsBasics
Genotype– The genetic makeup, as
distinguished from the physical appearance, of an organism or a group of organisms
Phenotype– The observable
physical or biochemical characteristics of an organism, as determined by both genetic makeup and environmental influences.
Chromosomes, DNA, and Chromosomes, DNA, and GenesGenes
CellCellNucleusNucleus
ChromosomesChromosomes
Gene
ProteinProtein
Adapted from Adapted from Understanding Gene TestingUnderstanding Gene Testing, NIH, 1995, NIH, 1995
The DNA Double HelixThe DNA Double Helix
Adenine (A)Adenine (A)
Thymine (T)Thymine (T)
Cytosine (C)Cytosine (C)
Guanine (G)Guanine (G)
BasesBases
Sugar Sugar phosphate phosphate backbonebackbone
Base pairBase pair
Mitosis and MeiosisMitosis and Meiosis
MitosisMitosis
MeiosisMeiosis(germ cells only)(germ cells only)
2N2N
2N2N
NN
NN
NN
NN
Allele SegregationAllele Segregation
Alleles: variant forms of the same gene (A Alleles: variant forms of the same gene (A a)a)
A aA a a aa a
A aA a a aa aA aA a a aa a
The Human GenomeThe Human Genome
23 pairs of chromosomes made of 700 million base pairs
30%70%
50,000–100,000 50,000–100,000 genesgenes
Extragenic Extragenic DNADNA
Repetitive Repetitive sequencessequences
Control regionsControl regionsSpacer DNA Spacer DNA
between genesbetween genesFunction mostly Function mostly
unknownunknown
Genetic CodeGenetic Code
A codon is made of 3 base pairs
64 codons total
1 codon (AUG) encodes 1 codon (AUG) encodes methionine methionine andand starts starts
translation of all proteinstranslation of all proteins
3 codons stop 3 codons stop protein protein
translationtranslation
61 codons encode 61 codons encode 20 amino acids20 amino acids
(redundant code)(redundant code)
U A A
A U G
Met
G C A
Ala
DNA Transcription and DNA Transcription and TranslationTranslation
mRNAmRNA
RibosomeRibosome
Growing Growing chain of chain of amino amino acidsacids
ProteinProtein
Nuclear Nuclear membranemembrane Cell Cell
membranemembraneDNADNA
Adapted from Adapted from Understanding Gene TestingUnderstanding Gene Testing, NIH, 1995, NIH, 1995
What does all this mean?What does all this mean?
Evolutionary PsychologyEvolutionary Psychology
Evolutionary psychologists believe that behaviour is strongly influenced by inherited factors, and that every human being acts (consciously, but mostly unconsciously) to enhance their inclusive fitness - i.e. to increase the frequency and distribution of their genes in future generations.
Or….Or….
The ultimate goal that the mind was designed to attain is maximizing the number of copies of the genes that created it. - Steven Pinker
Evolutionary PsychologyEvolutionary Psychology natural selection designed our
minds for life in an environment resembling the African savannah
It is only about 10,000 years since humans first started growing their own food
Environment of Evolutionary Adaptedness EEA. The EEA does not refer to some short period of time in our past. It refers to an array of factors that have influenced inclusive fitness during our evolution over the last 200,000 years
con’tcon’t
Adaptions evolve to meet challenges in the environment
Humans are adaptive animalsBehavior etc. is adaptive
Inherited TraitsInherited Traits
Eye ColorBehaviorAltruism
– Unselfish concern for the welfare of others; selflessness.
– Zoology. Instinctive cooperative behavior that is detrimental to the individual but contributes to the survival of the species.
AltruismAltruism
Exercise - Essay by Lewis ThomasAssignment
– Is altruism a genetic predetermined factor. Or is it, in the words of Richard Dawkins. “[that] we are born selfish. If we find that human behavior is altruistic, we will be faced with something that needs explaining.”