On Na'vi Biology
'Bioluminescence seems like a
valid evolutionary strategy'
By Nina Shen Rastogi
James Cameron's Avatar, which premieres on Friday, is already legendary for its meticulous attention to detail. Witness, for example, the hubbub over the invented alien language, which Cameron boasts will "out-Klingon Klingon."
Or the fact that he gave every plant and animal on the planet Na'vi, Latin, and common names, all catalogued in a 350-page "Pandorapedia."
Cameron seems to have been a little more lax in the biology department—at least when it comes to imagining Pandora's reigning creature, the Na'vi.
Take those already infamous alien boobs: He gleefully told Playboy, "Right from the beginning I said, ‘She's got to have tits,' even though that makes no sense because her race, the Na'vi, aren't placental mammals."
One hundred percent plausibility isn't required from any fantasy creature, of course. And if audiences grok those tall blue cat-people, then biological quibbles will be moot.
But Cameron's admission got the science nerd in me curious about the finer points of Na'vi anatomy—so I called up Stuart Sumida, a biologist at Cal State San Bernadino who moonlights as an anatomy consultant for FX studios.
(He helped work out how the mythical creatures of The Chronicles of Narnia should look and move.) I asked him to watch the Avatar trailer and pre-release clips and to offer an initial assessment of the Na'vi.
Sumida notes that the trickiest part of making a creature using motion-capture technology is that its movements remain essentially human. ("It's still basically a guy in a suit.") But with their long limbs, heavy tail, and opposable big toes, the Na'vi should move more like gibbons than bipedal humans.
And all that upright scampering across tree branches seems wrong, too, given how heavy a 10-foot-tall creature must be—even one with superlight bones.
Many of the choices that have obvious rationales from a storytelling perspective make for weird anatomy. Take those big, exotic eyes, which make the Na'vi look so cute and sympathetic. "Gigantic eyeballs are usually for creatures that forage exclusively at night," Sumida says.
"These characters should be wearing sunglasses—they get so much light, their eyes will hurt." And those expressive tails. Tails are an extension of the backbone, emerging downwards from the sacrum, where the hips attach. Na'vi tails, however, seem to emerge from above the sacrum, and they stick out at a nearly right angle.
Sumida also takes exception to the Pandorapedia's claims that those tails are prehensile—that is, used for grasping things—and help the Na'vi balance their long torso and legs. If that were the case, the Na'vi would probably be walking on all fours, with their backs parallel to the ground.
Articles on Avatar's alien biology and xenology. Some articles contain excerpt highlights, click on the source link for the complete article.
The Real Science of Avatar's Aliens
By Charles Q. Choi | Excerpt: space.com
Life is often huge on Pandora, with giant dragon-like flying creatures, skyscraper-high trees, and the blue-skinned Na'vi, who grow some 10 feet tall.
The gravity on Pandora is said to be lower than on Earth, which probably helps explain why everything is so outsized there, as they have less weight dragging them down.
Most of the animal life on Pandora is hexapodal — that is, six-limbed, for three pairs of either arms, legs or wings. One might expect six legs or more to be the norm on higher gravity worlds, to help them support their weight, but hexapods make up more than half of all known living creatures on Earth — the insects — so widespread hexapody falls within the realm of possibility.
The Na'vi are tetrapods, or four-limbed just like humans are, which at first makes them stick out like sore thumbs. Still, there are other tetrapods shown in the film — their flying mounts, the banshees or ikran, possess four wings as their limbs. This might intriguingly suggest the Na'vi are more closely related to these dragon-like animals than any of the land-dwellers shown in the film, although either Na'vi or banshees or both species might in fact come from a hexapodal lineage and merely shed two limbs, just as snakes got rid of their legs.
Apparently every living organism on Pandora is bioluminescent, meaning it can produce light. Bioluminescence is also seen on Earth, with fireflies and sea algae, among others. Many of the animals seem to possess two pairs of eyes — on Earth, insects not only have a pair of compound eyes, but a number of simple eyes as well. The 'nostrils' of Pandoran animals are often located on their bodies instead of their faces, and they often have more than two.
This suggests that instead of coupling the digestive and respiratory tracts together as humans and other tetrapods do — which can dangerously lead to choking — wildlife on Na'vi may separate these systems as insects do, which breath through holes dubbed spiracles. The biggest stretch of the imagination when it comes to biology on Pandora might actually be the Na'vi. Barring their blue skin and tails, they look remarkably human, with four limbs, nostrils on their face, and an upright posture that might not be aptly suited for a life spent mostly in the trees.
The females even have breasts, even though Cameron admits they aren't placental mammals, and we're extraordinarily lucky to find them when they are at a comparable level of intelligence as us — they might as easily fallen anywhere between animals barely capable of language to hyper-advanced cyborgs. Still, one might forgive a little poetic license in a film that in other ways apparently tried hard to get the science right might.
The Plausibility of the Na'vi Aliens
By Larry Klaes | Excerpt: centauri-dreams.org
How possible are the Na’vi and their environment? Will we find other alien intelligences who are even humanoids, to say nothing of having thought processes similar to ours? Or will evolving in similar environments bring about similar physiologies?
Note how there are many different types of creatures in the oceans of Earth, but their liquid ecosystem brings about similar physical features across a wide spectrum. Perhaps we might expect to find similar looking organisms swimming in the global ocean of Jupiter’s icy moon Europa.
I must admit, however, that once I got past the exoticness of being introduced to Pandora in 3-D, I was a bit disappointed at how familiar many creatures seemed, such as the animals the Na’vi rode: They bore more than a little resemblance to Earthly horses, just as those doglike creatures which attacked Jake early on resembled wolves or hyenas.
I still have to wonder how anything complex could live on Pandora so long as that moon remains so close to its huge parent planet. By all rights the little moon should be suffering massive quakes and eruptions of lava, but I saw no evidence of such activity. The ‘goddess’ Eywa, the complex biological organism every creature on Pandora seems to be a part of, had potential to be more interesting as a type of serious Gaia concept.
However, much of the biology of Eywa was lost in the spiritual and New Age aspects the film emphasized. While it is certainly understandable that beings like the Na’vi might only see Eywa as a deity, I found it a shame that the concept and entity could not be further explored in a more scientific manner, but then I suppose that would turn Avatar into some kind of nature documentary, albeit fictional.
Non-scientists, too, can revel in radiant 3-D jungle
By Carol Kaesuk Yoon | Source: thechronicleherald.ca
[Link no longer available]
When watching a Hollywood movie that has robed itself in the themes and paraphernalia of science, a scientist expects to feel anything from annoyance to infuriation at facts misconstrued or processes misrepresented. What a scientist does not expect is to enter into a state of ecstatic wonderment, to have the urge to leap up and shout: "Yes! That’s exactly what it’s like!" So it is time for all the biologists who have not yet done so to shut their laptops and run from their laboratories directly to the movie theatres, put on 3-D glasses and watch the film Avatar.
In fact, anyone who loves a biologist or may want to be one, or better yet, anyone who hates a biologist — and certainly everyone who has ever sneered at a tree-hugger — should do the same. Because the director James Cameron’s otherworldly tale of romance and battle, aliens and armadas, has somehow managed to do what no other film has done. It has re-created what is the heart of biology: the naked, heart-stopping wonder of really seeing the living world.
The real beauty of it, though, is that you do not have to be a scientist to enjoy the experience. Avatar is well within reach of becoming the highest-grossing film of all time. And while the movie’s dazzling animation and use of 3-D has received so much attention, it cannot be anything but the intense wonder so powerfully elicited, rather than merely the technical wizardry itself, that has people lining up to see it.
There have, of course, been many films that have depicted the excitement of scientists during discovery (think of Laura Dern in Jurassic Park, gleefully sticking her hand into a pile of dinosaur dung), and, from Lord of the Rings to Star Trek, there has been no shortage of on-screen fantastical floras and faunas.
But rather than having us giggling at a tribble or worrying over the safety of the children when a T. rex attacks, Cameron somehow has the audience seeing organisms in the tropical-forest-gone-mad of the planet Pandora just the way a biologist sees them. With each glance, we are reminded of organisms we already know, while marvelling over the new and trying quickly to put this novelty into some kind of sensible place in the mind. It is a mental tickle, and wonderful confusion sparks the thought, "Oh, that looks like a horse, but wait, it has six legs and it’s blue, and whoa, that looks like a jellyfish but it’s floating in the air and glowing."
The clues that we are "not in Kansas anymore," as we are told early on, can be seen in every aspect of the life of Pandora. If there is one colour that is most decidedly not a classic Earth tone, one that is least associated with living things, it might just be neon blue. And so many things on Pandora, like the Pterodactyl-like ikran and the deerlike yerik, are a staring, screaming blue. Another thing we do not expect from most living things is light. Yet on Pandora, life glows everywhere in the night, including the long, pulsating white Spanish-moss-like strands elegantly dangling off tree branches and the brightly glowing green and purple ferns.
And touching closest to home, Cameron has put a version of ourselves on Pandora, the Na’vi people, with whom he uses every trick. For they are blue, they have bioluminescing spots on their faces and they display the other of Pandora organisms’ stunning quirks: they are huge, at three metres tall.
To so strongly experience these kinds of wonderfully shocking similarities and dissimilarities among living things is the kind of experience that has largely been the prerogative of biologists — especially those known as taxonomists, who spend their days ordering and naming the living things on Earth. But now, thanks to Cameron, the entire world is not only experiencing this but also revelling in it.