Considering that biologists writing about life are writing an autobiography, it's not unreasonable to stick to the parts they can remember.
Eight-five percent of the history of life has been erased.
Why don't you elaborate upon this for us unlearned? Why was 85% of history of life erased?
85% erased? No problem on the “tree of life” if the branches are mostly bare, just crowd the other 15% closer together.