Lecture 17: Genes and Behaviour Flashcards
What are genes?
A lengths of DNA that encodes the information for constructing a particular protein
What are genotypes?
The entire set of genes an individual possesses (passed on by parents)
What are phenotypes?
The observable characteristic of an individual, influence by genes and environment
What are allele’s?
A version of a given gene
- Individuals have one or two alleles of a gene, but multiple alleles can exist in the population
What did Sokolowski (2001) say are the challenges of behavioural genetic research?
- difficulty in defining and quantifying behaviour
- environmental influences on behaviour
- within- and between-individual variation in behaviour
- involvement of many genes
- different genes function in different tissues at different times during the development of an organism
What is the burrow structure of deer mouse?
- lives in grassy/forest habitat
- builds burrows with short entrance tunnel and no escape tunnel
What is the burrow structure of oldfield mouse?
- lives in open habitats (beaches, fields)
- builds burrows with long entrance tunnel and escape tunnel
Explain Weber et al (2013) study?
- Captive-reared mice placed in sand-filled arena for first time builds species-typical burrow
-
F1 offspring of maniculatus × polionotus hybrid
- 100% escape tunnels
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Backcrossed F1 × maniculatus
- 50% escape tunnels
→ Single, dominant locus controls building of escape tunnel
How do genes contribute to behaviour?
Gene expression acts at different phenotypic levels
Expression of a gene can influence:
- expression of other genes
- activity of the cell, other tissues and organs
- developmental processes
- activity of brain, muscles, messenger systems → expression of behaviour
Environmental influences act on gene expression and/or on phenotype
What is total phenotypic variance in a trait?
Is based on addictive effects of genetic variance and environmental variance
Total phenotypic variance =
Genetic variance + environmental variance
Trait heritability =
Genetic variance / environmental variance
What kind of genetic mutations are beneficial and which are harmful?
Most a harmful and it is only rarely they are beneficial
What is mutant behaviour?
Memory not formed, therefore inspection needed at every trial
What is a normal behaviour?
Memory formed, therefore gradually less inspection needed
What are twin and adoption studies?
Twin and adoption studies investigate the genetic and environmental influences on human behaviour and cognition
What are the problems with twin and adoption studies?
- heritability estimates are not comparable across environmental contexts
- biased sampling across different family situations (→ confounding factors)
- comparisons do not clearly separate genetic and environmental effects
What is non-genetic inheritance?
Factors in one individual influence the behaviour or development of another individual (without passing on genes) who, in turn, may pass on these influences to another…
What is vertical transmission?
Between generations
What is horizontal transmission?
Within generations
What are epigenetics?
- Environmentally sensitive modifications of DNA and associated proteins that regulate gene expression without altering the genetic sequence itself.
- Epigenetic modifications can be transient or stable and can be induced by environmental factors.
- There is no convincing evidence of epigenetic inheritance in humans, though it has been evidenced in plants and simpler animal species.
