Final answer:
To fill out the geologic era events table, one must use known major biological and physical changes that occurred during each era. Precambrian included early earth formation and there's no specific event count, the Paleozoic had at least six major events including the Cambrian explosion, the Mesozoic had three major periods with pivotal evolutionary changes, and the Cenozoic had important mammalian developments in its epochs.
Step-by-step explanation:
To fill out the table for the number of events for each geologic era, we first need to understand how Earth's history is compartmentalized into different time frames. Geologic time is first divided into eons; notable eons during the Precambrian are the Hadean, Archean, and Proterozoic. Together, these are referred to as a 'super' eon. These eons are further divided into eras, and the eras into periods. For thes question, I will base the number of events on the relevant periods mentioned for each era.
- Precambrian: Since this includes several early eons not specifically broken down into further periods within the context of your question, it is challenging to provide the exact number of 'events'. However, notable events include the formation of the Earth and the evolution of early life.
- Paleozoic: This era includes the Cambrian explosion and the Permian extinction, encompassing six periods, so we can tentatively set the number of major events to at least six.
- Mesozoic: Known for major events in each of its three periods: Triassic, Jurassic, and Cretaceous. Each period housed significant evolutionary changes, including the rise and fall of dinosaurs. Therefore, we can consider at least three major events for the Mesozoic.
- Cenozoic: With the epochs within the Cenozoic, such as the development of modern mammals in the Quaternary and Tertiary, there would be at least two significant events recorded.
Total: Adding the events of each era would give us a minimum total event count; however, since each period could have multiple events, the specific total number cannot be precisely determined from the information provided.
Without a detailed list of specific events and the fact that the number of events can vary significantly depending on what is considered a notable event, the above numbers of events per era are a rough estimate based on major biological and physical changes known to have occurred during those times.