posted on Apr, 24 2005 @ 02:02 PM
(d) they are humans, but humans traveling in time from the future and so have diverged genetically to some degree
(e) they spent a very very long time with high technology to get the biology to work
Right now we can insert single genes from unrelated species. What that conceivable
30 or 50 years ago? Right now, we have just about decoded the human genome---but we
are just at the beginning of understanding the stupendously complex interactions between the molecules produced by the genes which result in life.
Look at the publications that have been done in molecular biology of 20 years (100,000s, maybe millions). Now imagine how much molecular biology
could be done in 10,000 years. Consider that humans may not be their first non-native species they've interacted with. Maybe they had 20,000 years
to practice on other mammals, or other animals on other planets.
They might have giant eco-parks of foreign species (to them) so that they can, say, breed billions of lab mice and rats to learn about foreign
It may be possible that they can breed non-fertile 'mules'.