Size / / /
Once our genes were our own,
or we were theirs,
horses they selfishly rode
into a Mendelian future,
but centuries ago we learned
the truth: the so-called human genome
was 90% bacterial. Who knew
we were carrying hitchhikers
in such intimate places?
When we reached 95%
it was time to do something.
Some of that stuff
was not pulling its weight, not
facilitating gene propagation—
actually it was slowing us down,
doing things we didn't need,
or doing nothing at all. So we
jettisoned that worthless 5%,
co-opted and improved
an inefficient metabolism
(we already catalyzed
many of its essential functions),
took over the remaining organ systems
(basically, we cut out the middleman),
and now we are really going places!