Natural selection disrupts the genetic equilibrium by favoring the genes for the traits that impart survival advantage to individuals.
Explanation:
Natural selection refers to the unequal survival rate of individuals of a population due to the presence of some beneficial adaptive genetic trait. These individuals are able to survive more and leave more progeny. Over generations, the population has increased number of these individuals leading to evolution of a population with different allele frequencies.
For example, the frequency of gene for antibiotic resistance in the bacterial population was increased once humans started using antibiotics to control the bacterial population. This led to the evolution of the bacterial population with antibiotic resistance.
Cora might have been diagnosed with another disease that presents similarly as tardive dyskinesia (this disease is a common adverse effect of antipsychotic drugs). Her misdiagnosis is most likely Sydenham's Chorea which affects people with rheumatic fevers. Other differentials include seizures and essential tremors.
