I don't know if this is similar to: https://www.researchgate.net/publication/10744818_Chain_Letters_and_Evolutionary_Histories https://www.researchgate.net/publ

I don't know if this is similar to: https://www.researchgate.net/publication/10744818_Chain_Letters_and_Evolutionary_Histories https://www.researchgate.net/publication/10744818_Chain_Lett... which if I recall correctly, drew an evolutionary tree of old school postal chain letters using normalized compression distance. I've also wondered if gzip is the best way of doing the compression. It compresses by block, and the decompression table(s) are in the file. It's not terribly hard to write a Huffman encoder where the character frequency table resides in a separate file. Huffman encoding isn't done by block, so it's inefficient compared to gzip as a compression method, but normalized compression difference isn't really reliant on best possible compression.