I hope you are having a great day! I would like to add to the excellent answer given by the expert SciB. I am unsure if you utilized the tips from a similar project here on ScienceBuddies, but I found the following project that may help (
https://www.sciencebuddies.org/science- ... nical#help)
Viruses evolve, or mutate, due to natural drift/mutations and selective pressures of the host (i.e. our immune systems); it is important to study the mutation of viruses to map their evolutionary changes, understand how they are transmitted from host-to-host, and aid in the development of vaccines and other therapeutics. From a bioinformatics standpoint, whole genome sequencing (WGS) is probably the highest throughput methodology available for analyzing genetic variation between viral strains. The CDC/WHO conduct "surveillance" for the flu viral strains every year -- more specifically, they determine the genome sequences of the strains and then do genetic characterization to determine similarities between the viruses, track their evolution, and develop vaccines (
https://www.cdc.gov/flu/about/professio ... zation.htm).
With this background information in mind, I think one feasible approach for your research question incorporates viral genetics and functional biology and ties the two together. Once you choose your virus of interest, you should study the proteins that make up the virus (you can use NCBI virus for sequencing:
https://www.ncbi.nlm.nih.gov/labs/virus/vssi/#/) and align two protein sequences (mutants) of your choice virus. Lower amounts of genetic variation indicate that founder effects may be present between two mutations, while higher variation may indicate that selective pressure has taken place. Another way to possibly determine if selective pressure is prominent is to analyze the functional relationships between the mutations. Note the key differences in the amino acid sequences between the strains and determine which proteins/amino acids are affected and how these mutations alter the overall functioning of the virus. For example, if you were to choose SARS-CoV-2, does one mutation of the SARS-CoV-2 virus alter the sequence of the spike protein -- if so, how does this mutation change the function of the spike protein in viral entry (i.e. is the virus less infectious, unable to enter the host cell as easily, etc). Mutations that cause functional changes often arise due to selective pressure so that the virus can survive, continue to be transmitted from host-to-host, and bypass/hijack the human immune system. Human behaviors, such as traveling, also affect the genetic makeup and mutation of a virus, so it is important to take this into account when studying viral genetics.
Again, these are just my ideas and I hope some of the information helps you devise a science fair project. I really recommend reading the links I have added, as I believe they are pertinent to your question. Let me know if you have any questions. It may be easier to develop a project once you have a narrower focus, select a virus, and formulate a hypothesis.
--Brandi