Answer:
This question is mainly related to diversity and evolution. Lower trophic levels means simple organisms in which evolution happened faster than the bigger trophic level organisms.
Step-by-step explanation:
In principle, faster evolution means more rapid change in genetic material. Therefore, simple organisms respond quickly to the changes in environment and they have more chances of going into separate lineage whereas in higher organisms it gets difficult. This is the reason that we have more diversity in smaller organisms as compared to the larger organisms.