Macroevolution can cause significant changes in the frequencies of alleles, that can ultimately result in speciation (forming of new species).
Various large-scale events like climate change and continental drift can greatly influence the distribution of species and adaptive radiation of different groups that can fill vacant ecological niches.
The changes in gene regulation and genetic mutations can also contribute to macroevolution by producing novel traits and adaptations.
The nucleus is still there.
Maybe it is nucleus or mitochondria!?
Answer:
Epidemiological Study
Explanation:
This type of study is called and epidemiological study. The design of this study uses a group or individual that have been exposed or not been exposed to a certain condition. The parameters will account for similar age, sex working habits etc. This will correctly identify if the contributing factor is the exposure of the agent or otherwise.