This is an example of microevolution.
Microevolution represents a small change in the genetic structure of the population. These changes manifest through the change in the allele frequencies of genes like in the case of dung beetles.
The causes of microevolution are evolutionary mechanisms, natural selection, genetic drift, mutations and gene flow.
Answer: food and drug administration
Explanation:
The changes in the grape juice happened due to the alcoholic fermentation of the grape juice that occurs due to the presence of aerobic bacteria. The presence of yeast is the main reason behind the process of fermentation taking place. The froth is produced due to the presence of the formation of acid and carbon dioxide.