What is this germline genetic engineering that's mentioned in the example citation? It's one of the two main ways that scientists are proposing to alter humans at the genetic level. The first method is called somatic gene therapy, and it involves injecting foreign genetic material into a person in the hope that the person's cells will take up that DNA. If successful, that person's cells will then start producing whatever proteins the DNA's gene or genes are meant to express. (Or they may stop producing certain proteins, such as those that cause the symptoms of a disease.)

The second method involves altering the existing genes of a fertilized egg. Such an egg is called a germ cell, so this method is known as germline genetic engineering.

The path to a posthuman world does not go through somatic gene therapy since that technique (which is already in clinical trials) only works on individuals: the genetic modifications are not passed on to the person's offspring. Germline tinkering, on the other hand, modifies the person's genetic makeup, and that makeup gets passed on to all of that person's descendants. Make enough modifications — vastly improved hearing, strength, endurance, and so on — and the result is a species that perhaps ought to be classified as something other than homo sapiens. (Particularly when you "augment" this genetic mutant with robotics and internal nano-machines designed to keep disease and physical obsolescence at bay.)

Thanks:
Mike Christie provided me with the earliest citations for this word.

Earliest Citation (adjective):