The Gaia hypothesis, according to which all physical and biological processes on Earth form a coherent self-regulating system, was first proposed in the 1960s by James Lovelock, an independent scientist, environmentalist and futurist, and Lynn Margulis, a microbiologist.
Lovelock named his theory after the ancient Greek goddess of Earth, and defined Gaia as a complex entity involving the Earth's biosphere, atmosphere, oceans, and soil; the totality constituting a feedback or cybernetic system which seeks an optimal physical and chemical environment for life on this planet. He claimed that the preferred state of Earth is homeostasis and, to put it simply, Earth can be perceived as a single organism. Here is Lovelock's explanation of this concept.
The theory has been widely criticised by scientists, particularly biologists, but acclaimed by many environmentalists.
Read more on Gaia here.
Although Dracunculus is a real genus of a parasite, and the species Dracunculus medinensis (commonly known as Guinea worm) does exist, Dracunculus borealis belongs to the realm of licentia poetica. The ancient Arctic worm was created by Peter Høeg for the purpose of this book - or at least not discovered by scientists... yet.