As a cattle farmer of long ago, I’ve always found it fascinating how evolution gave ruminants complex digestive systems for breaking down cellulose. However, cows can’t digest the lignin in older grasses and shrubs because the bacteria the cows depend upon can’t handle lignin in the same way as cellulose, even though both are polysaccharides. (Lignin is polyphobic so that is just one of many challenges bacteria face in trying to break down lignin.)
A lot of energy is bound up in lignin biomass so I’ve always thought fascinating the fact that most life on earth basically “ignores” lignin. So this article brought me new perspectives. (It came to mind because of what Dr. Swamidass posted about chitinase and insect-eating mammals.)