A lot of comments here people read this book and see it as depressing that we are violent and doomed to repeat the violence.

But I think books like this are frequently written as a warning that if we are not careful, this is what will happen.... not that the author thinks it will happen, and probably hopes his book will prevent it.

So I don't see it as depressing. And the ending of the book with the two headed woman, while it seems depressing, hints that there may be evolution in progress, that the survivors will not have the same issues.