30. If is difficult to visualize the scale of Earth's history. One analogy that is often used is
down all of Earth's history into one calendar year. This allows you to "see" how long one era is in
comparison to another.
I
a) If Earth's history has
lasted 4.6 billion years (4600 million years), and one calendar year has 365 days, how many years would be represented by
one calendar day? 12.6 Million
b) The Precambrian period lasted 4060 million
years. If the Precambrian period started on January 1 of our calendar, how many calendar days did it last?
c) The Paleozoic era would last how many days?
d) The Mesozoic era would last how many days?.
e) The Cenozoic era would last how many days?

1) When would the first humans appear on our one-year calendar?