Search humanoids based on silicon.

Fascinating conversation.

Silicates are worth thinking about.

In simplified form, the clay hypothesis runs as follows: Clays form naturally from silicates in solution. Clay crystals, as other crystals, preserve their external formal arrangement as they grow, snap and grow further. Masses of clay crystals of a particular external form may happen to affect their environment in ways which affect their chances of further replication — for example, a 'stickier' clay crystal is more likely to silt a stream bed, creating an environment conducive to further sedimentation. It is conceivable that such effects could extend to the creation of flat areas likely to be exposed to air, dry and turn to wind-borne dust, which could fall at random in other streams. Thus by simple, inorganic, physical processes, a selection environment might exist for the reproduction of clay crystals of the 'stickier' shape.
There follows a process of natural selection for clay crystals which trap certain forms of molecules to their surfaces (those which enhance their replication potential). Quite complex proto-organic molecules can be catalysed by the surface properties of silicates. The final step occurs when these complex molecules perform a 'Genetic Takeover' from their clay 'vehicle', becoming an independent locus of replication - an evolutionary moment that might be understood as the first exaptation.
Despite its frequent citation as a useful model of the kind of process that might have been involved in the prehistory of DNA, the 'clay hypothesis' of abiogenesis has not been widely accepted. As it was current and fashionable at that time, Richard Dawkins used it as the example model of abiogenesis in his 1986 book The Blind Watchmaker.

Hello all my responders,
maybe in the right conditions it can be possible. Perhaps we don't know, we are too carbon based.
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On earth, can only recall one type of creature/plant that uses Silica in any form. That is the sponge. Not exactly the intelligent lifeform we were looking for
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Proud member of TSWB.

End terrorism by building a school

we are also assuming these creatures would respire as we do. It could be that they'd just expel the spent Silica as nails or a shell of some sort.
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Proud member of TSWB.

End terrorism by building a school

Even though it may be possible for elements other than carbon, hydrogen, oxygen and nitrogen to combine in ways to make life possible it looks very doubtful. Carbon is the only element able to bond to itself and other elements in ways that are needed for life to function and water so far as we know is the only medium capable of allowing the necessary chemical and biological reactions to occur.

So there is probably about a 99% chance that any life, intelligent or otherwise will carbon based and that, I think, is why they don't spend any time looking for silicon based life forms, Remember the living rocks in Star Trek were the product of peoples imagination.
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Bob DeWoody