Basics of Biology

Biology and Life

Could life on Earth have been based on silicon instead of carbon?

Yes, technically, life on Earth could have been based on silicon instead of carbon because the element has the same bonding properties as carbon. But silicon is second only to carbon in its presence on Earth, thus carbon-based life evolved. (Note: Silicon is never found alone in nature, but always exists as silica [silicon dioxide] or silicates [made up of a compound made of silicon, oxygen, and at least one metal].) But that does not mean no organisms exist that contain silica. For example, a plant called horsetail has one of the highest contents of silica in the plant kingdom. Called a “living fossil,” it is the descendant of plants that lived over a hundred million years ago.


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