kurt@fluke.UUCP (Kurt Guntheroth) (12/10/84)
A central point which people seem to have missed is that DNA is not needed
for life to replicate. Imagine the most primitive proto-organism, a poorly
organized blob of organic chemicals with a membrane around it keeping the
whole thing from falling apart. It has few structures, since its needs are
few. It is simple and fragile.
Cells reproduce by splitting apart. The well organized cells around
nowadays have complex mechanisms which arrange for the genetic material to
be neatly divided into two copies, but what happens to the organelles? When
the cell divides, each half gets about(?) half of the cellular machinery.
Now imagine a simpler cell. It just splits. Usually each half is about the
same, so the two resulting cells resemble the parent. Sometimes one child
gets shortchanged, so it dies. Sometimes a fortuitous division leaves one
child better able to survive. Wow. Active, fast mutation. Now we have
self-replicating (sort of) cells with no DNA. Having a mechanism for cell
division that causes the children to more strongly resemble the parent
begins to become a survival trait (if the parent is successful), and the
probability of DNA evolving is increased greatly.
--
Kurt Guntheroth
John Fluke Mfg. Co., Inc.
{uw-beaver,decvax!microsof,ucbvax!lbl-csam,allegra,ssc-vax}!fluke!kurt