Week 3: Genetics and Evolution

Question 1

Genotype Environment Interactions

Answer 1

Increase the number of possible contacts between neurons

Question 2

Plasticity

Answer 2

Weak connection degrade while a few stable connections remain

Question 3

Phenotypic Plasticity

Answer 3

the ability of a single genotype to produce different phenotypes in response to variation in the environment

Question 4

Epigenetics

Answer 4

Changes in gene or cellular phenotype that do not involve altering the dna sequence itself

Question 5

Epigenetic Marks

Answer 5

Covalent DNA modification and posttranslational histone modification

Question 6

Epigenome

Answer 6

Wide distribution of epigenetic marks between differing cell types

Question 7

Identical Twins

Answer 7

Share same genome but may not have the same epigenetic marks

Question 8

DNA Modification

Answer 8

DNA Methylation - addition of methyl group on cytosine followed by guanine
DNA methytransferase - enzyme responsible for add the methyl

• If methylation occurs in promoter region it may silence gene expression
• In central nervous system so effects brain development

Question 9

Epigenetics and Early Childhood

Answer 9

• Positive parental attachment and parental investment program early epigenetics
• Affects memory, attention and emotion
  1. Biological defensive system for survival (stress resistance)
  2. Reproductive success
  3. Adequate parenting in next generation

Question 10

Histone Modification

Answer 10

Histone Acetylation - Addition of acetyl to histone tail (lysine)
Histone Acetyltransferase - add acetyl to the tail, promoting an open chromatin state and transcriptional activation
Histone Deacetylase (HDAC) - removes acetyl to close chromatin and reduce transcription

Question 11

Parental Investment and Stress Responses

Answer 11

Rat pups that received maternal nurturing show increases expression of the glucocorticoid receptors in the hippocampus
- Lower hormonal response to stress
- Increases histone acetylation and decrease DNA methylation

Question 12

Nutrition Epigenome

Answer 12

Nutrients can influence DNA methylation and histone modification, which are key mechanisms controlling gene activity.

Nutrients can act in two main ways:
1. Affecting enzymes that add or remove epigenetic marks (like DNA methyltransferases or histone acetyltransferases).
2. Changing the supply of substrates (molecules needed for these reactions, such as methyl group donors).

Question 13

Epigenetics in Learning and Memory

Answer 13

Epigenetic mechanisms influence genomic activity in the brain
- long term changes in synaptic signaling, organization and morphology
- Supports learning and memory

Question 14

MECP2

Answer 14

1. Represses gene expression by binding to DNA methylations
2. Aids protein packing
3. Influences gene expression that supports dendritic and synaptic development and hippocampus dependent memory

Question 15

CBP

Answer 15

Bind to specific histones and promote histone acetylation, thereby promoting gene expression

Question 16

Antidepressants

Answer 16

• Increase histone markers, reversing gene repression induced by defeat stress
  HDAC inhibitors - exert antidepressant effects

Question 17

Evolution

Answer 17

Changes to traits over time to develop advantageous for survival

Question 18

Natural Selection

Answer 18

Differential reproductive success as a consequence of differences in heritable attribute

Question 19

Adaptation

Answer 19

Traits or behaviours that evolved over time to increase reproductive success

For Survival:
Physiological: sweating, shivering, goosebumps.
Behavioural: fear of snakes, avoidance of spoiled food, parental protection.
Cognitive: memory for dangerous places or foods

Question 20

Sexual Selection

Answer 20

Evolution of characteristics because of the mating advantage it provided the organism

Question 21

Intrasexual Competition

Answer 21

Members of same sex compete against each other to win mate

Question 22

Intersexual Selection

Answer 22

Members of one sex (usually females) choose mates with desirable traits
- Peacocks

Question 23

Mutual Mate Choice

Answer 23

• found in humans
• Male and female have a say in mating choose
• Value qualities that benefit a long term relationship

Question 24

Individual Fitness

Answer 24

An individuals ability to survive and reproduce

Question 25

Inclusive Fitness

Answer 25

Helping genetic relatives survive and reproduce to pass on your genes

Question 26

Psychological Adaptations

Answer 26

Mechanisms of the mide that evolved to solve specific problems of survival or reproductions - Conceptualized as information processing devices - Emotional jealousy for reproduction

Question 27

Individualistic Cultures

Answer 27

Status determined by individual accomplishments

Question 28

Collectivist Cultures

Answer 28

Status determined by contributions to the group and the group's success

Question 29

Psychologic Adaptations Hypothesis

Answer 29

- Food preference, habit preference, mate preference and specialized fears - Include traits that improve people's ability to live in groups

Question 30

Sexual Strategies Theory

Answer 30

Humans evolved flexible mating strategies → short-term AND long-term. Influenced by: - Sex differences. - Individual “mate value.” - Cultural context. - Parental input. ex. Women more critical in choosing mate because of thier high parental investment

Question 31

Error Management Theory

Answer 31

Humans evolved biases in decision-making when outcomes are uncertain. Cost asymmetries: when one mistake is more costly than another, evolution favors bias toward the less costly error.

Question 31

Supported Prediction for SST

Answer 31

- Men desire more sexual partners than women. - Men fantasize about sex more often. - Men regret missed opportunities; women regret poor choices. - Both sexes become more selective in long-term mating. - Shared desired traits: kindness, loyalty, intelligence.

Question 32

Applications of EMT

Answer 32

1. Visual Descent Illusion - Heights look farther down than up. - Bias makes us cautious → reduces falling risk. 2. Auditory Looming Bias - Approaching sounds seem closer than they are. - Better to overreact (and dodge) than underestimate and get hit. 3. Sexual Overperception Bias (Men) - Men more likely to assume sexual interest when women are just friendly. Cost balance: - Mistake 1 (false positive): embarrassment. - Mistake 2 (false negative): missed chance to reproduce.

Question 33

Behavioural Genetics

Answer 33

Empirical science of how gene and environment combine to generate behaviour

Question 34

Adoptive Studies

Answer 34

- Behaviour genetic research - Comparison of adopted children to their adoptive and biological parents

Question 35

Quantitative Genetics

Answer 35

Scientific discipline in which similarities among individuals are analyzed based on biological relation

Question 35

Heritability Coefficient (h^2)

Answer 35

Measures how much of the variation in a trait within a population can be explained by genetic differences among individuals