Chapter 25.3, Problem 1LO

Summary Introduction

To evaluate: The strength of fossil evidence that date the life’s origin.

Introduction: Organic molecules are the foundation of all living beings. Organic molecules are formed from the inorganic molecules well before the appearance of cells showing the properties of life. Carbohydrates, nucleic acids, lipids, and proteins were also essential for life, however, not sufficient. For the evolution of cells, assembly of early organic molecules into an independent, functional unit is necessary. Around 3.8 billion years ago, life forms first appeared when the Earth became habitable.