An illustrative and vivid example of this comes from the movie Godzilla
. Admittedly a fictional example but some of the problems of hopeful monsters are considered. The story goes, that french nuclear testing
in Muroura 'mutates' a lizard into a gigantic fire breathing creature. So far, so unlikely - but the important point is the sex
of the creature. After lovable scientist Matthew Broderick
determines that the creature is pregnant
he makes the logical inference that it is asexual
Why is this logical? Well, hopeful monsters - if they ever exist - are very unlikely to happen twice with conveniently one of each sex. So propagation of the new species would have to be asexually.
Obviously, giant lizards are a little too hopeful; but I don't see why "drastic reorganisation of the entire genome" are 'forbidden'. After all, humans and chimps have almost the same number of chromosomes - if (as may have been postulated) there was a double stranded break in one chromosome, mightn't that make us hopeful monsters? ("Probably not", is the answer -I'm sure the story of human evolution has more chapters).