ence had uncovered the force of immortal renewal. It was an
invisible thread that connected the generations, a lineage of
microscopic primordial cells.
The German scientist August Weismann clearly understood
the implications of this observation. The cell theory implied
that life on our planet today likely originated many millions
of years ago from single-celled animals that were immortal.
By immortal Weismann did not mean to imply that they could
not be killed. Indeed, the struggle of the fittest implied that
their less-fit cousins did indeed die. By immortal Weismann
meant only that they need not die that given proper nutri-
tion, and barring some accident, any particular cell could
continue dividing, leaving no dead ancestors in its wake.
Weismann then suggested that these original immortal cells
may have clung to their daughter cells after dividing, thereby
forming a small cluster of identical cells. It is then easy to
imagine that these cells simply surrounded themselves with
daughter cells to aid in their competition for immortality.
One could imagine, for instance, that by holding hands
in this manner, they were better able to move through the
water, or perhaps better able to avoid being eaten by some
SPECIALIZATION OF CELLS
But complex, multicellular animals like you and me do
leave dead ancestors behind. When and why did that happen?
Here is where Weismann made a revolutionary proposal.
He surmised that some of the cells in this cluster changed
in a profound manner. When the largest animal was still a
small cluster of cells perhaps something like the ball of cells
called Volvox, the microscopic pond water animal some of
these primordial and immortal cells specialized in a subtle way