So let's talk about taumoeba, astrophage, and predator-prey dynamics.
This was part of the book that bothered me the most, mostly because the rest of the science felt really well-done and at least somewhat thought out (let's not talk about the Sahara project), but this was one area that felt like even a simple skim of the topic should 1) reveal the blatant errors in the book's science and 2) add some cool stuff to talk about in my field that would have been really interesting!
(I'm less bothered by that part of the movie because they didn't say enough to say anything wrong. That's a whole other thing. But at least doesn't involve my field of research :) )
(science below the cut)
(oh hey I can really talk about this stuff. part 1 of 2)
What we know about astrophage is that it's a microorganism that "eats" solar radiation (hence the name) and travels to reproduce around Venus, creating the infamous Petrova line. The dimming of the sun was a slow, gradual process, and there's no Petrova line going anywhere else, so presumably the Sun (and other stars) were "infected" by a handful of dispersing astrophage that slowly built up a population. What that means is that, if all the astrophage around Earth's Sun are destroyed, the Sun may get re-infected later, but there'll be a period with no astrophage.
This is important.
What we know about taumoeba is that it lives in the atmosphere of Adrian and eats astrophage. There are other organisms in Adrian's atmosphere, but they do not eat astrophage, and taumoeba can breed and survive without them for at least long enough for Grace to genetically engineer some nitrogen-resistant strains.
Book!Grace takes this knowledge and decides that, if they introduce taumoeba to the solar system, it will eat all of the astrophage and the problem will be solved. Huzzah! Unfortunately, that's not how this works.
What happens when a predator and a prey species exist in isolation is what's called a Lotka-Volterra curve or equation or model. The predator eats the prey and produces lots of new predators, who eat more prey. Eventually, the prey can't keep up and start to die out. But without enough prey, the predators also start to die out. Eventually, there's not enough predators to hunt down the last of the prey, so the prey population recovers. And on it goes in a pair of lovely wavy curves.
This actually almost never happens on Earth because ecosystems are so complex - when starving, a predator will switch to less preferred prey or migrate (hm), which can keep populations going. But in a space ecosystem with just two species, it's perfect! Grace should be super excited to find the perfect setting for the Lotka-Volterra model to actually work! I am!
So unfortunately, unless they manage to absolutely flood Venus with so many taumoeba they completely wipe out the astrophage in one go before the taumoeba all starve to death, it's not a perfect solution. And even that won't work in the long-term, since the Sun could get reinfected with astrophage and whoops all the taumoeba have starved.
(I suppose they could maintain captive populations on Earth, but given the danger of astrophage escaping to resume eating the Sun, that seems risky.)
What is most likely to happen instead is that Earth will have to adjust to periodic heating and cooling as astrophage populations fluctuate. Ideally it'll eventually reach the equilibrium seen on Tau Ceti, but things are going to be touch and go for a bit even if it does reach equilibrium, and provided that equilibrium isn't reliant on other microbes in Adrian's atmosphere.
You can clearly see from this dramatic video that the winner between the giant green anaconda & the 300-350 lb jaguar is the jaguar. Anacondas weigh between 200 and 300 pounds on average, but some weigh over 500 pounds and can grow up to 20 feet in length. Anacondas' powerful muscles and flexible spines enable them to crush predators through constriction; they are non-venomous. Anacondas spend most of their time in the water in Amazonian & Orinoco wetlands because water supports their mass, letting them strike with more control. Encounters between these two predators are not that common, far less than the viral videos would have you believe. While jaguars kill anacondas, they donât go looking for them the way they hunt capybaras or caiman.
Both anacondas & jaguars share habitat, but anacondas spend most of their time submerged in slow water, hidden, while jaguars patrol riverbanks & are great swimmers (second only to the tiger) but spend most of their time on land. Jaguars kill using a skull-piercing powerful bite. How powerful? 1,500 psi, which is like biting through a cast iron skilletâa jaguar can crack it like a cookie. Or like slamming a steel door on a bone or all the weight of a refrigerator on one toothâthatâs the kind of pressure weâre talking about. Jaguars are also very agile both on land & in water, & their ambush ability is equal to or better than the snakeâs. For this reason, most anacondas shy away from jaguars whenever possible. Evolution over the past 2-3 million years has taught the snake that jaguars are one of the few predators that can reliably kill them.
