22 Biological Immortality people did not die off as fast as demographers expected. But human survival data are hard to interpret scientifically, given the confusing effects of wars and improvements in medical practice. It might be that the considerable benefits of medical practice have been especially profound among the oldest old. Human cohorts do not supply good data for scientific infer- ence. Human data were never going to give a clear answer to the question of the implacability of aging. Things  changed  dramatically  in  the  early  1990’s  when insect cohorts were used to study mortality rates late in life. [6;7] In caged insects, kept under good conditions, mortality rates stop increasing in late life. [8–10] The new facts of death reveal three phases of mortality: juvenile, aging, and late life. In the juvenile period, mortality rates do not show sustained increases. In the aging phase, mortality rates increase rapidly. In the third phase of life, mortality rates are roughly constant, though they tend to maintain a very high level. Organisms that reach the third phase can be said to be biological immor- tal, in that they no longer age. This is the new immortality that I wish to introduce to discussions of the attainment of human immortality. But before doing so, I want to put the new immortality into a general biological context. One way in which we can classify organisms is to divide those that are always immortal from those that have a period of rapidly increasing mortality rates – aging –prior to a period of immortality. The aging species age first and then are immortal. Immortality is thus the universal condition of life. Aging is the less common condition. This is a fact of enormous significance for the long-term future of the human species.