Final answer:
Ice ages have occurred during the Quaternary Period, which began about 1.8 million years ago. Evidence such as the presence of ice sheets and geological and paleontological findings support the occurrence of ice ages on Earth.
Step-by-step explanation:
Ice ages have occurred on Earth during the Quaternary Period, which began about 1.8 million years ago and continues to the present day. The Quaternary Period is characterized by cooling climate, leading to a series of ice ages.
One evidence that supports the hypothesis of ice ages is the presence of ice sheets that covered large portions of the Northern Hemisphere. For example, during the most recent glaciation period, which occurred between eighteen thousand to one million years ago, ice sheets extended over vast areas, and sea levels were much lower than they are today.
In addition, scientists have found various geological and paleontological evidence, such as the presence of glacial deposits, land bridges between continents due to lowered sea levels, and the adaptation of certain animals to cold climates, to further support the occurrence of ice ages on Earth.