Final answer:
To determine which mutation caused a bigger change, the types of mutations must be compared. Frameshift mutations generally have a more significant effect than substitutions. The specific effect of each mutation on protein function and gene expression would further clarify which had the greater impact.
Step-by-step explanation:
When evaluating whether the first or second mutation caused a bigger change, we must consider the type of mutations they were. An insertion or deletion mutation, also known as a frameshift mutation, typically has a more drastic effect on the genetic code than a substitution mutation.
This is because a frameshift mutation shifts the entire reading frame of the codons, which can result in a completely different sequence of amino acids and potentially a nonfunctional protein. In contrast, a substitution may only change a single amino acid, and sometimes, due to the redundancy of the genetic code or the 'wobble' base phenomenon, it might not change the amino acid sequence at all.
Therefore, if the first mutation is a frameshift and the second mutation is a substitution, the first mutation would likely cause a bigger change. Conversely, if the first mutation is a silent substitution and the second is a frameshift, then the second would be more impactful.
Understanding the specific details of the mutations and their effects on gene expression and protein function can further clarify which mutation had the greater impact. Mutations can also introduce changes in the protein that might lead to beneficial, neutral, or negative effects on the organism, depending on the context and environment.