Chapter 23, Problem 15TYK

Summary Introduction

To review:

The geological evolution of the Earth has had adverse effects on the biological evolution. The rise in the atmospheric oxygen concentration at earlier times was due to the release of the oxygen by photosynthetic organisms. The human activities are changing the physical environment on the Earth. The kinds of selection pressures that are established by these environmental alterations.

Introduction:

The geological history of the Earth includes some major events that took place in history and are categorized on the basis of the geological time scale. The Earth formed around 4.54 billion years ago and at this point, the evolution of the Earth started. Then, some minor changes (volcanic eruptions, settling down of dust and gas, and condensation of water vapors) took place that led to the occurrence of some major events (Pangaea formation, continents broke apart, and formation of glaciers).