“I’m trying to understand this deep connection that people have to the forest. She talks about a network of energy that flows through all living things.” That’s Jake Sully, a human soldier inhabiting the body of a Na’vi, an indigenous species of the moon Pandora in James Cameron’s Avatar. Sully comes to realize and admire the bond the Na’vi have with their environment and Pandora’s other native flora and fauna. When a Na’vi rides a direhorse, for example, the braids from their hair intertwine with the ‘reins’ of the creature, to form “tsaheylu“, a kind of psychic connection that allows both beings to mentally fuse and operate as one.
Cameron explains to us how he conceived the tsaheylu bond: “I was thinking, what if all of nature…was kind of one giant nervous system, a little bit like our internet, and that you could actually plug in and this is your USB port, you have this thing that connects directly into your brain.
“Then I thought, well, then you braid your hair over it to protect it, because it’s delicate neural tissue, right, and then you can connect with animals. And you can connect with these trees that are input-output centres, basically, for this vast neural net. That just seemed like a cool idea and I ran with it.”
In effect, Avatar’s tsaheylu bond is extrapolating on biology already found on Earth. “What Cameron is describing here, is essentially what we call mutualism,” explains Dan Eatherley, nature writer and author of the critically acclaimed Invasive Aliens. “Mutualism is where two different organisms form symbiotic relationships that seemingly benefit both of them.”
The psychic connection, or mind-melding, that is tsaheylu in Avatar isn’t quite replicated at the complex organism level in the real world. “The only corollary here would be something like the fungal parasite that can mind-control ants, that we’ve discussed before, where the parasite exploits the poor insect for its own nefarious reasons. But that’s not exactly mutually beneficial, and certainly not to the ant,” chuckles Eatherley. “In our biology, it’s either going on at a more simple or singular cellular level, or the mutualism is in the form of give-and-take symbiotic relationships.”
Let’s take a look at nature, then, and the phenomena and relationships existing in real life that most closely resemble Avatar’s tsaheylu bond.
Symbiotic Relationships — Pollination
“You could look at this as one of nature’s oldest symbiotic relationships,” offers Eatherley. “The plant hoodwinks another organism to spread its pollen, the male sex cells. But even this likely adapted, as initially, insects were just eating the pollen itself, which obviously is a bit of an evolutionary dead end for the plants. So, the plants kind of distracted the insects with this lovely sugary nectar stuff instead and then they would just accidentally pick up the pollen. And of course, it’s not just insects, also bats and some birds, like hummingbirds, can pollinate too.”
Symbiotic Relationships — The Feeder/Cleaner Dynamic
Wildlife audiences are often fascinated by the relationship between a huge predator and the smaller, seemingly vulnerable animal who appears to be in no danger despite regular close proximity to these fearsome beasts.
“You see this with the Nile crocodile and the Egyptian plover bird,” says Eatherley. “The plover sits inside the croc’s open jaws, eating small pieces of food left over in its mouth, and effectively offering a kind of dental service!”
You can watch this symbiotic relationship in the video embedded above.
There’s a corollary in the sea too, as shown here.
“You see this with sharks and pilot fish, or in Australia, the grey reef sharks and the cleaner wrasse fish,” Eatherley notes. “These small fish again provide a valuable service by removing food fragments which they themselves feed off, as well as parasites that could become harmful for the sharks.”
Symbiotic Relationships — Scary Clown(fish) House Guest
Anyone recalling the traumatic opening scene of Finding Nemo will remember that Marlin and his ill-fated spouse Coral make their home in the swaying, toxic tentacles of a sea anemone. Nemo’s plot development requires that their multiple eggs aren’t laid inside this living deathtrap, whereas that’s usually the clownfish strategy.
“The clownfish gets to hide from predators in amongst the stinging tentacles, because it has a layer of mucus on its body that negates the anemone’s poison,” Eatherley explains. “And the anemone gets a load of benefits from the clownfish like the parasites being removed or being provided with nutrients through their faeces. It’s also possible the bright orange and white-striped colours of the clownfish help attract other fish that the anemone can then sting and ingest.
Symbiotic Relationships — “Are You the Farmer?”
Aphids are often the bane of gardeners everywhere when they swarm on vegetation and devour it. One might think that ants, who want to eat the honeydew aphids produce, were simply their natural predator, but it doesn’t quite work like that.
“The ants feed on honeydew produced by aphids and actually also offer protection in return,” explains Eatherley. “Some ants will even move the aphid eggs and nymphs underground to their nest, which makes harvesting the honeydew more efficient, like the equivalent of a dairy farm. So, these are the basic kind of exchanges of benefit.”
Endosymbiosis: Two Become One
Endosymbiosis is where one organism lives within the body or cells of another.
“Lichen are the union of two single-cell organisms: fungi and algae,” says Eatherley. “The fungus provides the firmer shape and structure, and the algae is able to photosynthesise. Both benefit here: the fungi gets oxygen and food, and the algae gets an anchor and substrate to grow on.”
Sunfight at the OK Coral
When snorkelling or diving, it might be disturbing to imagine that the coral reefs are living creatures, but it’s true; they’re colonies that have joined and spread over hundreds of years.
“Coral is actually made up of tiny creatures called polyps,” Eatherley outlines. “Each polyp starts acquiring millions of tiny algae or zooxanthellae (‘zoots’ for short) which photosynthesise, providing the coral with the vast majority of its food. The zoots also give the coral its particular colour. And it’s when coral becomes stressed that they expel their algae which in turn leads to coral bleaching and eventually death.”
Make Room for the Mushrooms: Fungi
“I just watched a documentary recently about these giant mushrooms and the connectivity,” Avatar producer Jon Landau tells us. “Literally how they’re all connected, and they react to one another, and they’re in touch.”
It sounds fantastical, and there may be something to it. “There’s been research announced recently looking at whether fungi are communicating with electrical impulses,” confirms Eatherley, “effectively a ‘language’ of their own, with up to 50 ‘words’. Of course, living cells can communicate with one another, but that’s through transmissions in nerves or a nervous system, which fungi don’t have.”
What fungi do have are thread-like filaments called hyphae, which in turn form a thin web called a mycelium that links fungal colonies within the soil and is akin to a nervous system. “Scientists are measuring and analysing the electronic signals being sent,” Eatherley points out, “but we’re still a way off confirming that fungi are indeed talking amongst themselves.”
What has been evidenced, are what are called mycorrhizal fungi, extensive networks in the soil that connect different plants and help them gain access to nutrients and moisture supplied by these fungi. It helps the plants survive by providing a much wider range of sustenance, and at the same time, the plants can transfer sugars and fatty acids to the fungi – another crucial example of mutualism at work.
“I think it’s a wonderful idea,” marvels Landau. “I also think that it serves to remind us that even though we’re not all physically connected, we are really connected.”
Cameron’s Future Connections
Avatar: The Way of Water introduces stunningly immersive new undersea worlds to explore and, inevitably, new creatures. Perhaps most impressive of all is the tulkun, super-intelligent, whale-like animals, capable of communicating and forming intimate bonds with the Na’vi. And unsurprisingly, given his planned further sequels, James Cameron has ideas he’s yet to explore on screen.
“We don’t say it in the movie, but when you connect with one of these underwater creatures that’s able to hold its breath for 20, 30 minutes, some oxygen can come across that bond, it’s not just neural signals,” he explains. “And in fact, a mother can treat it almost like an external umbilical. So the child is actually born at the end of the second trimester, and then lives connected to the mom via the tsaheylu bond for the last trimester. There’s all sorts of little variants on that biology that are quite well worked out in the canon, but haven’t showed up yet in movie two, but will show up over time.”
“I’m sure plenty of other astonishing mutualistic relationships in the natural world are just waiting to be discovered by scientists,” says Eatherley. “So, this will definitely be a rich seam for moviemakers to mine in the future.”
Avatar: The Way of Water hits screens on December 16, 2022.
Catch our interviews with Avatar: The Way of Water director James Cameron, producer Jon Landau, and the cast below.
