Numeral systems other than unary used in nature or in animal and human behaviours Representing numeric values using positional notation is one of the milestones in the history of arithmetic. Babylons used a base 60 system, Maya a base 20 system; base 10 system became "the standard" used by modern civilizations; digital computers use the Binary numeral system, ....

But if we look at nature, we found that life itself "heavily rely" on an alphabet of 4 symbols: the DNA has four (chemical) bases: adenine, cytosine, guanine and thymine (A, C, G, T) that are used to store the "instructions and information" to generate and drive the parts of a living organism.


But on a higher level, are there "natural algorithms" (algorithms found in natural processes, in animal behaviours or in everyday human behaviours) that take advantages of "numeral systems" other than the unary representation. 


To be more precise I would like to know whether or not natural processes or living creatures make use of a finite, discrete alphabet of "symbols" and use them in a manner similar to a positional notation: the symbols are placed together and used as a whole to  represent "something" (an action, an information, an object, ...) among many other possibilites ... a sort of "index" in an exponential number of possibilites.

Another (obvious) non numeric example is the human language where (in general) a combination of finite number of sounds ("alphabet") are combined to form the words.
There is at least one example where a string of symbols from an alphabet is also used: proteins.

Proteins consist of chains of 20 different amino acids (usually, in some cases, it's 21 or 22) and the sequence of amino acids determines what given protein does.

This example is closely related to the DNA example you gave, because each amino acid in a protein is encoded by a triplet of bases in DNA.

For more information, see the article Genetic code on Wikipedia.