The subject these scientists are interested is the brain. They want to know whether the abnormal spindle gene (ASPM gene), important for encoding human homologue for spindle function, is responsible for an abnormal brain growth disorder (MCPH). They know that during primate evolution there has been a significant increase in brain growth, but are unaware of what causes this increase. The central nervous system is the only thing being affected by individuals whom have MCPH. To test their hypothesis, they use Koch’s Postulates to identify whether the ASPM gene is responsible to MCPH. In this study (Kouprina, 2004), they isolated the ASPM gene homologue from gorillas, orangutan, chimpanzee and macaque through Transformation Associated Recombination
