BIOL1003 Lecture Notes - Lecture 20: Selective Breeding, Molecular Genetics, Heritability
Tinbergen’s four questions
1. Development– learning & growth
2. Mechanism– senses & physiology
3. Adaptive function– contribution to survival & reproduction
4. Evolutionary history– changes from ancestors
Example: Why do hares change colour
1. Development: roles of genes & then environment during development?
2. Mechanism: does day length or temperature affect colour change?
3. Adaptive function: does color affect survival?4. Evolutionary history: color of
ancestors?
Is behavior heritable?
Testing for heritability of behavior
1. Correlation between parents
& offspring e.g. blackcaps
2. Cross-breeding experiments
e.g. blackcaps
3. Artificial selection
experiments —> look for response to selection e.g. crickets,
dogs
4. Molecular genetics e.g. voles
Example: migration in blackcaps
• Parents leave
• Young migrate later at night from breeding ground to Africa
• Direction and distance varies between populations
• heritable?
Studying migration in captivity
Nesting raised in captivity
Study nocturnal restlessness in cages
Record magnitude and direction of escape from cages
—> Direction of migration is encoded in their genes
Document Summary
Tinbergen"s four questions: development learning & growth, mechanism senses & physiology, adaptive function contribution to survival & reproduction, evolutionary history changes from ancestors. Example: why do hares change colour: development: roles of genes & then environment during development, mechanism: does day length or temperature affect colour change, adaptive function: does color affect survival?4. Testing for heritability of behavior: correlation between parents. & offspring e. g. blackcaps: cross-breeding experiments e. g. blackcaps, artificial selection experiments > look for response to selection e. g. crickets, dogs, molecular genetics e. g. voles. Record magnitude and direction of escape from cages. > direction of migration is encoded in their genes. Some strains of bees are resistant to infected pupa. Two components of behavior: (1) uncap cell of dead pupa (2) remove dead pupa from hive > less likely to be an epidemic > hive is less vulnerable to the disease. Two different gene loci: (1) u doesn"t uncap; u uncaps (2) r doesn"t remove; r removes.
