Original sentence: An expert in ancient biomolecules has proposed a novel, untested, ad-hoc unknown mechanism for this unusual find: "My suspicion is this process has led to the reaction of more resistant molecules with the normal proteins and carbohydrates which make up these cellular structures, and replaced them, so that we have a very tough, resistant, very lipid-rich material - a polymer that would be very difficult to break down and characterise, but which has preserved the structure"
Edited sentence: However, an expert in ancient biomolecules has proposed a novel unknown mechanism for this unusual find: "My suspicion is this process has led to the reaction of more resistant molecules with the normal proteins and carbohydrates which make up these cellular structures, and replaced them, so that we have a very tough, resistant, very lipid-rich material - a polymer that would be very difficult to break down and characterise, but which has preserved the structure"