Summarize the evidence showing that the sequence of nucleotides in a gene is colinear with the sequence of amino acids in a protein.

A DNA is the genetic material of the organism which gets transferred to progeny controlling their traits. The DNA contains a sequence of nucleotides which codes for a protein called genes which provide instruction of the trait.

The DNA forms an mRNA molecule which by the process of Transcription and this mRNA molecule gets translated into the protein by Translation.  Translation proceeds in the ribosomes where mRNA bases are studied by the ribosomes in the form of triplets called codons. Each codon codes for a specific amino acid which gets bonded to form a polypeptide.  

Since the sequence of bases form codons which form the proteins in the same sequence as they are arranged on the mRNA, therefore nucleotides of the gene are collinear with the amino acids if the proteins.