Again outdated biology. Significant parts were outdated when Sawyer wrote this. Like the whole bit with »there is no fusion site, the telomeres from gene 2 and 3 (should have been 12 and 13) completely disappeared« was known to be wrong for over ten years by then. There are basically two telomeres stuck together in the middle of chromosome 2. That is how we know it was a fusion, and have known since 1991.

The end was very rushed, narratively. What to do with the personal villain? Have him commit suicide. Elaborate what it means that only women but not men can move to the parallel world? Eh, not worth more than about a page of text. What to do with the whole god organ? Have everyone have a vision at the same time, but I’m out of paper, so I can’t do anything with this.

And one more thing for the whole trilogy: The thing is very gender essentialist. Men this, women that. Men have XY chromosomes, women XX. Men are hunters, women gatherers. Oh, yeah. Literal mammoth hunters. Looking at real hunter gatherer societies, it is never that strict. Even here we have one woman hunter, but she’s a literal outlaw, in the »not protected (!) by law« sense.

Again, you can read this without thinking too much about it, and than it is an OK book.