When an avatar is "born" (or more properly decanted) as a post-adolescent, it looks like a Na'vi, and can live comfortably on Pandora, but it has enough human neurophysiology to be used as an avatar, or surrogate body. The human volunteer then becomes a "controller" or "driver". Using Psionic Link technology, the human controller can remotely control the avatar body out in the wilds of Pandora, receiving all sensory input and providing all motor control to the body. Essentially, the controller lives through the avatar, and is completely unaware of his or her human body while linked. Each avatar is genetically keyed to its respective human controller.
Humans use this method because they cannot live on Pandora without breathing gear because the atmosphere is toxic to humans, containing lethal levels of carbon dioxide (>18%) and Hydrogen Sulfide (>1%). The Avatar Project was originally intended to create mine workers who did not need environmental protection systems and could eat Pandoran foodstuffs, but the cost of the mental-link system remained too high for the numbers needed. Avatars are now used only for field work and, when the opportunity arises, to interact with the Na'vi and study them. It was hoped that the avatars could act as unofficial ambassadors, but Na'vi have for the most part viewed these hybrid creatures with a mix of contempt and mistrust. Now, avatars mainly serve as a means for communication with the aboriginal population. The RDA has been trying to bridge the cultural gap and improve relations with the Na'vi. However, this task has been difficult due to communication and negotiation issues. Avatars, therefore, serve important roles as mediators by relaying cultural information and demands to each party in a peaceful manner. The Na'vi refer to them as "dreamwalkers" or "demons in false bodies."
By communicating with the locals through avatars, which appear less alien to them, the RDA has had some success teaching them English and basic skills.
Creation and birthEdit
The Avatar Program scientists take DNA from a Na'vi and from a selected human volunteer. On Earth, in genetics labs, they create an in-vitro embryo, which is a genetic composite of the alien and human donor. The cost of each avatar is roughly five billion dollars ($5,000,000,000). The recombinant embryo is grown in-vitro during the flight to Pandora, which takes 3 years ship-time (5 years Earth time due to relativistic effects). In that time it reaches near adult size, since avatars mature much more rapidly than humans.
During the flight, the avatar progresses from coin-sized embryo to a near adult size of nine feet (2.75m). Gentle blue light tailored to mimic the natural Pandoran daylight spectrum aids skin formation and guarantees amniotic fluid sterility. Nutrient-rich broth is circulated through an artificial placenta, a purpose-designed matrix of spongiform blood vessels and monitoring electrodes. Engineered hormones are used to stimulate rapid growth and ensure correct organ development and muscle tone during the interstellar journey. Avatars are normally grown 'en-route' to Pandora while their operators sleep in cryo-hibernation for the journey.
While the embryos in-vitro wince like dreaming babies, when "born" they are neither sentient nor animate, have no mind or free will of their own; their brains operate only through a psionic link with a human driver. The avatar body is simply an empty vessel intended for use as a surrogate body by the human operator. The avatars grown for Jake Sully and Norm Spellman were decanted from their tanks shortly after their arrival at the Hell's Gate BioLab complex.
After decantation, the artificial placental matrix and umbilical is removed. The wound heals naturally over the course of a few days.
Once all tests confirm maturation is completed and all wounds are healing, the avatar is ready for initial motor cortex testwork and neural interface link up.
An avatar was created and cryo berth reserved for scientist Tom Sully aboard the ISV Venture Star, scheduled to arrive at Pandora in mid 2154. However Tom met an untimely death at the hands of thieves a week before embarking for Pandora. His twin brother Jake was quickly recruited by RDA agents into the Avatar Program. Since Jake's genetic makeup was identical to his brother, the avatar created for Tom could be used by Jake, albeit with no training prior to his arrival on Pandora.
The completed, fully grown avatar is much closer to the long-limbed Na'vi than human in appearance; typical adult size ranges from eight to ten feet (2.5 - 3.0m) tall with blue skin, bioluminescent markings and large eyes with golden iris. Sensitive ears, a tail and the Na'vi queue, a unique set of nerve endings normally braided into a hair-like configuration protruding from the base of the skull, are faithfully reproduced to be near identical to the Na'vi.
Respiration, musculo-skeletal structure, internal organ function and arrangement are comparable to the Na'vi, enabling sustained precision operation in the hostile Pandoran atmosphere and jungle environment. The avatar also includes reproductive organs but further data has not been released.
The avatar body possesses greater strength and resistance than their human driver, owing this to carbon fibers in their bones. This quality greatly improves resistance to accidental damage, impact from falls etc. especially while the operator acclimatises to his/her Avatar.
An avatar cannot function independently of its operator - if the operator is not actively linked, an avatar remains inactive in a state of restful sleep.
Some known differences between the avatars and Na'vi are due to the influence of human DNA.
- Critically, the avatar brain and nervous system are modeled to precisely match that of its human operator while still maintaining appropriate Na'vi cellular biology. The avatar also possesses the necessary nervous system pathways required for the control interface.
- Avatars retain the human configuration of five digits on each hand and foot, rather than the native Na'vi who possess four digits on each limb.
- Avatars possess eyebrows, while the Na'vi are hairless apart from their scalp and a small tuff of hair on the tips of their tails.
- Avatars display slightly more human-like body musculature and structure than the Na'vi. (this is especially apparent when comparing the build of Jake Sully to that of the male Na'vi of the Omaticaya clan; Jake's body structure is sturdier than those of the more willowy Na'vi).
- The Na'vi have large lemur-like eyes, while the eyes of an avatar are usually smaller and more human-like.
- The Na'vi nose is flat and cat-like, while the nose of the avatar has a more human-like pronounced central ridge.
- The queue of an avatar starts at the base of the skull, whereas a Na'vi queue starts at the top of the skull. The reason for this is not clear.
It is possible, using the unique biology of Pandora and assistance of the Na'vi, for a human to transfer his/her conscious mind permanently into an avatar body. The method is first tried in an attempt to save the life of Avatar Program's lead scientist, Grace Augustine. However, the transfer fails due to earlier injuries. A second attempt is made on Jake Sully after he led the Na'vi to victory against the RDA and drove them (with some exceptions) off Pandora. The movie concludes with his human body being exposed to the moon's atmosphere, and his avatar body opening its eyes. This confirms that the consciousness transfer succeeded.