Big History (Early Earth and Origin of Life)

Modern origin of life theorists regard life as a

"complex system" composed of the same ordinary matter as non- living entities.

Our oxygen atmosphere is a product of what?

A product of later photosynthesizing organisms.

What do theorists considered an entity to be alive?

Am entity must utilize processes for reproduction, metabolism, and adaptation.

Why do theorists assume life began where plenty of liquid water was available?

Because of the crucial role of water in living organisms

What are some factors that could lead to the exact site of life's origins and the cause of transformation from non-living to living?

The availability of raw materials such as amino acids and nucleic acids (which can form in outer space and arrive on Earth in meteorites), the emergence of cell-like entities through chemical evolution, and the emergence of self-replicating molecules.

What do theorists believe allowed the transition from non-living to living happen?

Theorists assume that there must have been an energy source to drive increased complexity. Possible energy sources on early Earth include volcanoes, lightning, and ultraviolet radiation.

Early Researchers searched for...

a "life substance" or "life force"

The exact site of life's origins and the cause of transformation from non-living to living are both...

unknown.

What did fossil evidence show us when life first appeared?

Life appeared on Earth about 1 billion years after the planet formed and appears to have been bacteria.

What did early bacteria use for energy?

Photosynthesis which is converting the carbon dioxide atmosphere of the early Earth into the oxygen