Question

The Phanerozoic era, known as Evident life, ranges from:

a. 4.6 to 3.8 Ga
b. 3.8 to 2.5 Ga
c. 2.5 to 0.6 Ga
d. 0.6 Ga to present

Answer 1

The Phanerozoic era, noted for its evident life, spans from 541 million years ago to the present, comprising the Paleozoic, Mesozoic, and Cenozoic eras.

Step-by-step explanation:

The Phanerozoic era, also known as the era of 'Evident Life', is the current geological eon in the geologic time scale and ranges from 541 million years ago to the present day. This eon is known for its abundance of animal and plant life and encompasses major geological periods including the Paleozoic, Mesozoic, and Cenozoic eras. Within the Phanerozoic, the Paleozoic Era is characterized as the age of "old life" and spans from 544 million to 245 million years ago, beginning with the Cambrian explosion and ending with the Permian extinction. Following this, the Mesozoic and Cenozoic eras unfold, with the latter being referred to as the era of "modern life" or the age of mammals, starting approximately 65 million years ago and continuing to the present.

Answer 2

The Phanerozoic era ranges from 541 million years to present, encompassing the Cambrian Period to modern times, which makes the correct answer d. 0.6 Ga (541 million years) to present.

Step-by-step explanation:

The Phanerozoic era, known as Evident life, is the current geologic eon in the geologic time scale, characterized by an abundance of animal and plant life. It began with the Cambrian Period. The Phanerozoic is subdivided into three eras: the Paleozoic, Mesozoic and Cenozoic.

The Paleozoic Era marks the age of "old life" from approximately 544 million years ago and is known to have ended with the massive Permian extinction about 245 million years ago. Following the Paleozoic is the Mesozoic commonly referred to as the age of dinosaurs and then the Cenozoic Era also known as the age of mammals which spans from about 65 million years ago to the present. Therefore, the correct option for the time range of the Phanerozoic era is d. 0.6 Ga (541 million years) to present.