Honestly, I would change that question to is relegating all life forms, universally, into a carbon based life form bracket only realistic? Carbon represents approximately 45- 50% of all dry biomass thus making it a primary component of all known life on Earth. Although all other types of biochemistry are only hypothetical, would it not be very difficult to say with certainty that a statement that is applicable to all life on Earth will apply to all life throughout the universe too? Questioned <PERSON> who coined this conclusion as Carbon Chauvinism. The attributes that life on Earth disclose might be a mere universal norm or a blueprint for life at every level of hierarchy. Planetary conditions even in our solar system vary and if living organisms were to exist in other planets other than Earth, their biochemistry would have to adapt to their specific conditions down from their macroscopic to their subatomic scale. Therefore biochemical and biological variation is probable.
An example is a Silicon Based Biochemistry. 759
Using directed evolution, which is a method used in protein engineering, that mimics the process of natural selection to steer proteins toward a userdefined goal, scientist <PERSON> and her team have performed stages of mutations on a microbe’s enzyme that they considered in principle, had the capability of manipulating silicon and guided it into engineering a protein that they catalysed to successfully generate carbon to silicone bonds which was before, never heard of in the bounds of nature. The enzyme ended up creating 20 different bonds 19 of which were new to science. Silicone is in itself very similar to carbon in that, its atoms can also form up to four valence bonds with other atoms simultaneously. More over, silicon is one of the most common elements in the universe. As a matter of fact, silicon makes up almost 30% of the mass of the earth’s crust . Therefore it is possible that what is thought of as ‘life’ elsewhere, is based on chains of Silicon atoms with a few other atoms and instead of using water as a solvent, they use another solvent with as many of the characteristics useful for doing chemical reactions and has a broad temperature range as a liquid that corresponds to the temperature conditions within such as Ammonia. 731