In the other chapters, I could easily break the subject matter
into problems faced by many different organisms. In this chapter,
I wanted to focus on one organism: a small animal, known
as a bdelloid rotifer, that lives in patches of wet moss.
Bdelloid rotifers are notorious in evolutionary circles because
they do something that evolutionary theorists thought was
impossible. That is, they only reproduce asexually--by
laying eggs that don't need to be fertilized--and
have done so for at least 85 million years. In other words,
they are "ancient asexuals".
Asexuality often evolves, but it rarely persists for long:
asexual groups tend to go extinct almost immediately. This
is one of the chief reasons that evolutionary biologists believe
that sex is necessary. But if the bdelloid rotifers can live
for millions of years without sex--why can't the
rest of us?
Having the bdelloid rotifer as a guest on a TV show seemed
to me to be a good way of keeping the chapter focused on this
question. Moreover, ancient asexuality is a contentious topic
in evolutionary theory, and I thought that the best way to
convey the debate would be to have a debate. Each member of
the audience who speaks is advocating a real position held
by real scientists. For example, a ram argues that most claims
of ancient asexuality have turned out to be bogus, and so
probably, the bdelloid rotifers' claim to ancient asexuality
will turn out to be bogus too. Several people in the pages
of scientific journals have made this argument. However, the
rotifer is able to show (by referring to the very latest
studies) that in fact, the bdelloid rotifers really are
ancient asexuals. And so on.