Animal research in genetics

Question 1

Selective breeding

Answer 1

When animals are bred with the goal of producing a specific endophenotypes.

More specifically, modern research using selective breeding often uses knockout mice which are mice that have had a single gene changed or removed.

Question 2

Cases et al (1995) and link to Caspi et al (2002)

Answer 2

Aim: To investigate the genetic origins of aggression

Procedure: Knockout mice that were missing the gene that regulates the enzyme that breaks down serotonin had offspring with high levels of serotonin and high levels of aggression.

Caspi et al (2002) carried out a longitudinal study on around 400 boys from when they were born. They looked at the genotype of the boys - particularly the same gene in above study and found that if the boys had the version of the gene that resulted in low levels of enzyme production, they were more likely to bully others and engage in aggressive and antisocial behavior. This confirms the findings in the animal finding, creating external validity.

Question 3

Cases et al 1995 2 pros, 2 cons

Answer 3

• Research confirmed the animal model (such as Caspi)
• Experimental so causality and higher internal validity
• Ethical concerns about using animals in such a manner as it leads to permanent damage
• Even though research confirms human research, it is still questionable if animal models truly reflect human aggression.