Genes, Evolution and Behavior

1
Genes, Evolution and Behavior

• How does genetic predisposition influence
  behavior?

2
Behavior Genetics

• Behavior Genetics
• study of the relative power and limits of genetic
  and environmental influences on behavior

3
Genes Their Location and Composition
4
Genes Our Biological Blueprint

• Chromosomes
• threadlike structures made of DNA that contain
  the genes
• DNA (deoxyribonucleic acid)
• complex molecule containing the genetic
  information that makes up the chromosomes
• has two strands-forming a double helix- held
  together by bonds between pairs of nucleotides

5
Genes Our Biological Blueprint

• Genes
• biochemical units of heredity that make up the
  chromosomes
• a segment of DNA capable of synthesizing a protein

6
Dominant and Recessive Genes
Mo T Her S Genes
Fathers two Genes
M O T H E R G E N e
F1
F2
M1
M2
7
Finger length etc

• Ring finger vs. Forefinger
• -Draw a line
• Results
• Short forefinger is recessive in females
• More males have short forefingers
• Thumb bend?
• prayer hands

8
Taste Sensitivity- PTC Sodium Benzoate

• Results
• If you have the recessive gene-no taste
• Approx- 70 taste
• -30 No Taste
• (must be own saliva)
• SB- 1) Bitter-salty 2) Bitter-sweet
• 3)Bitter-Bitter 4) Tasteless-salty
• Like spinach, turnips, sauerkraut.

9
Behavior Genetics

• Identical Twins
• develop from a single fertilized egg that splits
  in two, creating two genetically identical
  organisms
• Fraternal Twins
• develop from separate eggs
• genetically no closer than brothers and sisters,
  but they share the fetal environment

10
Behavior Genetics

• Temperament
• a persons characteristic emotional reactivity
  and intensity
• Interaction
• the effect of one factor (such as the
  environment) depends on another factor (such as
  heredity)

11
Minnesota Twins Study

• Striking Similarities
• Body Double Film

12
Evolutionary Psychology

• Natural Selection
• the principle that, among the range of inherited
  trait variations, those that lead to increase
  reproduction and survival will most likely be
  passed on to succeeding generations
• Mutation
• a random error in gene replication that leads to
  genetic damage

13
Are our preferences inherited?

• Survey 1
• Results ( board)
• Survey 2
• Results ( board)