Essential Knowledge 1.D.2

Scientific evidence from many different disciplines supports models of the origin of life.

Geological evidence provides support for models of the origin of life on Earth. The Earth formed approximately 4.6 billion years ago (bya), and the environment was too hostile for life until 3.0 bya, while the earliest fossil evidence for life dates to 3.5 bya. Taken together, this evidence provides a plausible range of dates when the origin of life could have occurred. Chemical experiments have shown that it is possible to form complex organic molecules from inorganic molecules in the absence of life.

Molecular and genetic evidence from extant and extinct organisms indicates that all organisms on Earth share a common ancestral origin of life. Scientific evidence includes molecular building blocks that are common to all life forms. Scientific evidence includes a common genetic code.

Students should be able to:

LO 1.32 Justify the selection of geological, physical, and chemical data that reveal early Earth conditions.