I’m not sure that this question is suitable for this list, which is intended for questions from students of biology, not questions from students of the physical sciences who would like biology to fit into the sort of framework they understand. However…
First, genetics has been variously defined throughout history — Wikipedia currently has “Genetics is a branch of biology concerned with the study of genes, genetic variation, and heredity in organisms”, but I do not think current research is concerned with “establish(ing) a relationship between a certain genotype and certain phenotype”. Phenotypes are not where it’s at.
I stand to be corrected, but I think the question behind the post can be put simply as:
Why can’t we predict the function of a gene and its product from the
And the answer is simply:
Because the DNA sequence does not provide enough information for us to
do that. For the benefit of the physical scientist I’d say it’s like trying to determine the value of several unknowns with an insufficient number of simultaneous equations.
Let me use some analogies to explain further.
- It’s like trying to assemble IKEA furniture without instructions.
- Or, worse, it’s like trying to determine the function of a single component of IKEA furniture without even knowing whether it’a part of a Rågifarsok or a Nässeltrjik.
- Or someone thinking that the instructions for a Nässeltrjik will tell you how to build a Rågifarsok.
- Or, if you don’t do IKEA, it’s like a person transported in time from the middle ages trying to guess what the blueprint for an internal combustion engine means.
- Or for the same person to guess what a screwdriver does.
That’s why biology is an experimental science.