Essays on Infinite Lifespans
Michael D. West
conditions they always eventually exhausted this ability and
arrested their growth.
When I entered the field of aging research in the late 1970s,
Hayflicks observation was already dogma. Humans are an
amalgam of cells, some mortal and others immortal. Everyone
is painfully aware of the mortal ones. Like bricks that are mor-
tared side by side to construct the walls of buildings, so our
cells are cemented together to form the tissues of our bodies.
And those tissues our bones, blood, and skin and the cells
from which they are made are all destined to age. We are
made of mortal stuff. Our bodys cells and therefore our
bodies themselves share a common sentence of death. So, it
may surprise you to learn that there is an exception.
HEIRS OF OUR IMMORTAL LEGACY
Still resident in the human body are potential heirs of our
immortal legacy, cells that have the potential to leave no dead
ancestors; cells from a lineage called the germ-line. These cells
have the ability for immortal renewal as demonstrated by the
fact that babies are born young, and those babies have the poten-
tial to someday make their own babies, and so on, forever.
In 1997, we at Geron Corporation, along with a host of
collaborators, finally succeeded in isolating the gene that we
reasoned should impart this capacity for unlimited replica-
tion in germ-line cells. The gene encodes a protein called
telomerase that rewinds the clock of aging at the ends of the
chromosome. The isolation of this immortality gene stirred
considerable controversy as to its potential to rewind the
Hayflick clock in cells in the human body after we showed
that it actually works on cells cultured in a laboratory dish.
Introducing the gene in an active state literally stops cellu-
lar aging. The cells become immortal but are still otherwise