Dragons are the best (or worst) Invasive Species

I’ve recently I fell down a hole and became obsessed with The Memoirs of Lady Trent by Marie Brennan. If you haven’t read the series, I highly recommend it. Especially if you’re a woman in STEM, since the main character, Isabella, is a woman making her way as a scientist in a fictional version of the 1800’s(ish). Also the science is pretty spot on.

So then why am I here? Pretty much all the science in the books are fairly well explained. There aren’t any glaring errors. Well, true to time period, while Isabella manages very well looking at the specific natural history of the organism of interest (Dragons) she doesn’t really look at how they fit into their environments, she doesn’t ask ecological questions. And given that I’m an ecology nerd, I’m here to add some additional depth to some very specific events in these books.

There aren’t any spoilers from the first book in the series in here, but heavy spoilers for the second book ahead, so be warned. And yes, the actual science is important to the plots of these books. I know squeaked on the inside when I realized that too. Please go read them.

Okay, now that I’ve gotten that out of my system: Ecology.

In the second book of the series, The Tropic of Serpents, Isabella is in a fictional version of Africa researching Swamp Wyrms in well…a swamp. Shocking, I know. Through various plot events, it is revealed to her that the piranhas living in the waters of the swamp are actually an early developmental stage of the adult dragons. Additionally, to create female dragons the people living in the swamp move the eggs into another area, changing the conditions enough to create females. If the eggs are not moved they become males. The males are significantly smaller than the females and are morphologically distinct (they look different). Long story short, in order to prevent a dam from ruining the way of life of the people in the swamp, it is agreed that the larval-stage Dragons will be transplanted to the waters of the nation state that controls the territory, Bayembe. They will then develop into dragons, which will not be able to mate since they are only male or only female because they all hatched in the same conditions, and will guard the city from an impending invasion from the south. In return, the rivers leading up to the large jungle swamp/rain forest will not be dammed.

How would these introduced dragons impact the aquatic ecosystem outside of Bayembe?

Well let’s look at the real root of the problem here: these are big animals that have to eat with no natural predators in their ecosystem (or any ecosystem as it seems likely that Swamp Wyrms are apex predators). How big of a problem is this? Well, it’s hard to say. It isn’t really noted in the series how often Swamp Wyrms have to eat, but other species of dragon have a single large meal every few days. This is much closer to a snake or another ectotherm than to mammals and birds, which have to eat continuously to be able to maintain their internal body temperature. In that case, these specific dragons might be closest to a crocodile or an alligator.

American alligators have been found to consume: giant water bugs, apple snails, crayfish, round-tailed muskrats, marsh rabbits, red-bellied turtles, peninsular cooters, stinkpots, gizzard shad, and Florida gar. That’s a large variety. But the little bugs and snails and crayfish were mostly food for adolescents, while the larger prey was eaten by adults. Additionally, females ate more mammals while males ate more reptiles, in particular turtles.[1] Isabella thinks that the invasive Wyrms may be developing into females, so in that case we are talking about a mammal population that is most at risk. Additionally, crocodiles in Australia have been found to eat crabs, shrimps, and fish in addition to mammals and birds; the type of food eaten appears to be largely impacted by the type of habitat and by the salinity of the environment. This change in diet based on environmental facts also lines up with Swamp Wyrms physiological changes in changing conditions.[2] A juvenile saltwater crocodile needs 4% of its body weight in food a week to continue its rate of growth.[3] So, let’s assume that the growth rate is the same for our dragons. Let’s also assume that their minimum weight is the same as a male crocodile, although that’s probably way too low. So a male saltwater crocodile weighs in at a maximum of about 1000kg (about 2200lbs). So that individual would need to eat 40kg (that’s 88lbs) of food every day. That’s the size of a not-very-small child.

That’s a lot of food. Swamp Wyrms are native to rain forests, an area with some of the highest biodiversity on the planet and plenty of food to support them. The area that they have been moved to is, in comparison, a literal desert. Sure, this is a watery ecosystem, but they have also been moved from a delta to a much more salty bay that is surrounded by desert and grass lands. Now, the water next to the desert my actually be fairly nutrient rich thanks to all the minerals and salts from the sand that would blow into the water. Microbes like to eat this stuff, and then bigger stuff eats the microbes, and so up the chain. However, this would not compare to the rain forest that the Swamp Wyrms are native to.  Although the soils in rain forests are pretty nutrient poor because of constant erosion, there are so many other large animals to pull into the water and consume that they would have a much easier time getting to that 40kg minimum than an open ocean ecosystem. Additionally, this rain forest happens to be in the middle of a delta, which is a double win for biodiversity since deltas are areas where salt and freshwater mix. This leads to both salt and freshwater organisms being able to live in different parts of the delta along the salt gradient, rather than just the salt-loving species of the open ocean that would live next to Bayembe.

There is also the Swamp Wyrms hunting style to take into account. They release a noxious gas that disorients their prey, then leap out of the water and eat the prey. That means that while they may supplement their diet with aquatic organisms, their primary food source is land mammals and birds.  These are going to be in much shorter supply than in the rain forest, where water ways passed under low hanging trees and vines that a mammal could be snatched out of. Plus, mammal are unlikely to go near the salty water consistently since they would be seeking freshwater resources. Birds may hunt for fish in salt water, which would provide the Swamp Wyrms with some food, but the birds would quickly learn to avoid the area and definitely would not get the dragons to their 40kg minimum of food.

Honestly, the animal that is most at risk is the very animals that the dragons were put there to protect, humans. Humans use the ocean for economic and recreational purposes, and fishing is doubtlessly an industry. It would take far less effort to eat a child that has been stunned by noxious gas and is not a particularly strong swimmer than it is to, say, catch a bird mid-air. Sure, they might also go after seals and sea lions, but both of these animals are far harder to catch in the water than a human would be. And considering in this fictional nation, the poorer people live by the water while the nobles live in a compound slightly inland, it seems likely that the water would be used not only for recreation and fishing, but also for washing clothing and bodies as well as defecating. Sure, it is salt water and not ideal for those sort of things, but these people are very poor and live in an arid climate where fresh water would be reserved for drinking. This puts these populations even more at risk, since they would be constantly by the water and if anything were to happen it is unlikely that the nobility would be held accountable. In the end, introducing Swamp Wyrms to Bayembe may help defend the nobility against invaders, but far more likely to kill large numbers of common people compared to the numbers that would be killed in an invasion.

So there are few things that could happen in this scenario:

1.The Swamp Wyrms die could out before they are large enough to take down a person/before they get out of their larval fish phase. This leads to the collapse of the population. Things return to normal unless more Swamp Wyrms are introduced.

2.The Swamp Wyrms could grow to a size that they can take down a person. To get to this size they probably have to eat through a decent amount of the native species. Then, if more Swamp Wyrms are continually introduced, many people would die to support the adult population and the bird and fish population would be continually preyed upon by the juveniles. Over time this would lead to a decline in diversity and may cause ecological collapse.If there is ecological collapse of the marine community then the local economy based on fishing collapses AND the Swamp Wyrms die from lack of food since they will not be able to grow large enough to prey on humans. Or, additional food sources could be introduced to the bay where the Swamp Wyrms live. This could prevent the adult dragons from preying upon humans entirely, but it also could upset other parts of the ecosystem.

Either it seems like humans have to actively manage the problem, just as they have to continuously bring in new dragons, or they have to accept that humans are likely to be the primary food source for this animal. In the long term it will likely hurt the economy of Bayembe simply because of the inevitable decline in the number of fish, in addition to the potential of staggering human loss. However, it makes sense that Isabella didn’t consider these factors when she used Swamp Wyrms as a bargaining chip. Ecology is a fairly new study, one that does not appear to have been developed sooner in her fictional world. Additionally, just as in the real world, global trade appears to have kicked off in the past century with industrialization. Many invasive species are a result of greater global interconnections. Every invasive species has a native habitat. Isabella lives in a world where this is not yet considered to be a major problem, although if her world’s history follows our own it soon will be and the consequences will likely be very severe.

TLDR: Don’t introduce giant lizards into new waters unless you’ve really thought this through.
[1] Delany, Michael F., and C. L. Abercrombie. “American alligator food habits in northcentral Florida.” The Journal of Wildlife Management (1986): 348-353.

[2] Taylor, Janet Ann. “The foods and feeding habits of subadult Crocodylus porosus Schneider in northern Australia.” Wildlife Research 6.3 (1979): 347-359.

[3] Webb, Grahame JW, Gregory J. Hollis, and S. Charlie Manolis. “Feeding, growth, and food conversion rates of wild juvenile saltwater crocodiles (Crocodylus porosus).” Journal of Herpetology (1991): 462-473.

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Fantastic Beasts and Conservation

When I first went to see “Fantastic Beasts and Where to Find Them”, I was prepared to be excited for the first new Harry Potter movie in years. I was not expecting to get excited about the biology showcased in the movie, that being that Newt Scamander does a lot of things that actual Naturalists did in the 1920’s. That being said, this essay will have spoilers for the movie, so tread with caution.

Before the movie even beings, Newt is traveling across the world collecting specimens of magical creatures in a briefcase for a book that he is writing. This was (and still is) often done by scientists to better study and understand animals. The key difference is that muggle/our specimens are, more often than not, dead. While thanks to the power of magically large suitcases Newt’s are very much still alive. Despite this, the work Newt had to do to study these animals is likely similar to the work of real-world naturalists. The most obvious example of field work that most people know about would probably be Charles Darwin and his journey to the Galapagos Islands. From that trip he sketched and described species of finches and tortoises and collected evidence for his theory of Evolution which he then published in “The Origin of Species”. Newt, like Darwin, is also collecting specimens as research for an upcoming book and would revolutionize the way the natural world was viewed by the general public. However, Darwin published his writings in 1859, at least 60 years before Newt and his suitcase. But there are a lot more examples of field work of this nature in the real world, closer to when Newt would have been working.

Carl Akeley changed the field of Taxidermy in the late 1800 and early 1900’s, shifting the field from a way to display hokey hunting trophies to an educational and scientific tool. A good example of this was “The Four Seasons” exhibit at the Chicago Field Museum, which depicted a group of white tailed deer and their transition through the year. Weirdly, white tailed deer were endangered at the time and this allowed people who lived in the city to see them.[1] While today it may seem cruel to kill an animal for a display, at the time it was considered one of the best ways to educate the public. Sure, you may never be able to go to Africa to see an elephant, and if you saw a wolf up close it might be the last thing you ever saw, but you could go to a museum and see one. This allowed for the average American to see wildlife as something at least interesting, if not beautiful. Even today Taxidermy is still used. By having specimens of a species from different points in time, scientists can better understand how human factors (urbanization, climate change,and pollution just to mention a few) have affected species. The animals that Newt is collecting would serve a similar role, and we see this several times in the movie when he takes people into his brief case. Their attitudes quickly shift from fear (Wizards in the movie refer to the magical creatures as pests or look for some practical use for them) to amazement, just like museum exhibits did for public opinion of the natural world in the 1900’s.

In addition to museums, zoos also shaped public opinion. Zoos existed thousands of years, largely as a display of wealth and power, while zoos after the enlightenment (1700s) had at least some emphasis on science and studying the animals that were inside of the enclosures. The goals of zoos was to make the enclosures similar to the natural habitat of the animal, however in practice conditions were cramped and inhumane to the animals inside of them.[2] Newt’s case is actually a good example of an ideal zoo for the time period. The enclosures aren’t large, although he is using it as temporary transport so I wouldn’t be surprised if he has more suitable enclosures planned. Each animal had a separate area, with tarps painted to look like its natural habitat. The entire layout exists somewhere between a wildlife area and a museum. Newt uses these animals for study, which he plans on publishing in his book. Scientists today do the same thing, although usually by going to a natural protected area and observing them in a more natural setting. However both of their goals are largely the same, to better understand the natural world around them and to educate the general public.

Why all this interest in the environment around the 1900’s? One of the first big factors happened in 1914, when the last Passenger Pigeon went extinct. In 1860 there may have been 3.7 billion Passenger Pigeons, they were on the scale of being considered a plague when they descended upon a field to roost. They lived in huge flocks, which were then captured in nets in mass as well as more accurate sport shooting guns. This lead to them becoming extinct in a short amount of time. They disappeared so quickly that people kinda freaked out, which is understandable. But nothing was done to try to conserve them until 1909, which was 40 years too late.[3] But this is when people really began to pay attention to endangered animals.

However, well into the nineteenth century, popular culture played a huge role in the way people viewed the environment. The earliest beginnings of the environmental movement could be seen in the writing Thoreau and his book Walden, which focused on the human condition and the natural world. Additionally,  many early American painters that focused largely on landscapes. These painters are often considered the first American painters, since many were not trained in Europe and chose to focus on key elements of American life, which they linked to the landscape. These drawings and paintings shifted public opinion of nature as something to be fear and exploited, to nature as part of the national identity for many Americans. These images were used by the National Park Service, which was created in 1916, to promote the National Parks as a way to escape the city. [4]

This doesn’t seem to have happened in the Wizarding World. Magical creatures are still viewed as pests and the reaction to Newt’s interest in them is often met with confusion. Magical creatures do not seem to have shaped the identity of white wizards the way that it did for their white muggle counterparts.  (I specify white wizards, because the Thunderbird was featured in the movie, and it seems unlikely that native wizards wouldn’t hold such a magical creature in high regard.) It seems that other factors, like maybe persecution, had a larger hand in shaping the identity of white wizards. Given that muggles and wizards were not allowed to interact, it isn’t surprising that they wouldn’t have read the books or seen the paintings or even have visited the museums that so deeply affected their non-magical counterparts. They may have not even had the chance to go to museums or zoos. As a result the wizards in “Fantastic Beasts and Where to Find Them” are a good snap shot of how Americans viewed the world around them before the natural world was tied to the American identity.

Looking at how magical creatures are viewed in the main Harry Potter series, Newt’s book is a long reaching and long lasting influence. It not only is a text book, it leads to a complete shift in the relationship between magical creatures and wizards that for the non-magical world took centuries of slow change. For example, Harry and Hermione in “Prisoner of Azkaban” go back to save Buckbeak (a Hippogryff) and Sirius Black, while if Buckbeak were simply viewed as a tool for Wizards to accomplish their goals they likely wouldn’t have cared. In addition the existence of Charlie Weasley, who cared enough about Dragons to fly with his work buddies to break into a school and save one, shows just how much Newt’s book changed the outlook of Wizards. While the creators of Fantastic Beats and Where to Find them may have not intended to show case how public outreach and science were done in the early twentieth century, they managed to do so while still exploring a magical plot line.

[1] “Carl Akeley’s Four Seasons” Youtube, uploaded by thebrainscoop, 4 December 2013, https://www.youtube.com/watch?v=zUkbYp1Gyrg&t=206s

[2] “Zoo: Encyclopedic Entry” National Geographic, http://nationalgeographic.org/encyclopedia/zoo/

[3] “Year of the Passenger Pigeon” Youtube, uploaded by thebrainscoop, 10 September 2014 https://www.youtube.com/watch?v=FPRpX25L5DU

[4] “The Evolution of the Conservation Movement, 1850-1920” The Library of Congress, http://www.loc.gov/teachers/classroommaterials/connections/conservation/history.html

Dennis, Disease, and Abilities

Note: this was originally posted on my blog on tumblr.com. I have tried to convert some of the formatting over, however there may be some inconsistencies. Also this particular entry was written before I knew how to cite scientific sources, so sources will either be nonexistent or incorrectly cited. 

This meta is going to look at how the genetics of abilities in Heroes/Heroes Reborn can go totally wrong, and how a little boy named Dennis is evidence of that.

It was pointed out in this meta that Luke’s son, Dennis, likely has some sort of skin condition, since he is always covered pretty much head to toe by clothing. Given that Luke has an ability I have thoughts on this. Read them below the cut. Beware, science.

Continue reading “Dennis, Disease, and Abilities”

Elle and Creating Electricity

Note: this was originally posted on my blog on tumblr.com. I have tried to convert some of the formatting over, however there may be some inconsistencies. Also this particular entry was written before I knew how to cite scientific sources, so sources will either be nonexistent or incorrectly cited. 

In case you didn’t know, most humans (and animals) can’t shoot electricity from their hands. I’m sorry if I just destroyed some childhood dream of yours there.

Still there are some animals, mostly fish, that have an ability that is comparable to Elle’s. They can create electric fields and use them to see, find mates, talk, and some of them can even use these fields to kill and stun prey.

The most famous of these fish that you probably have heard of is the electric eel, but there are loads more (also platypuses because they just can’t be normal like every other mammal). The thing that makes the eel special is that it can produce 600 volts of electricity, which won’t do anything to a human but would definitely kill the tiny fish that the eel eats. Most other electric animals don’t have that type of fire power.

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Speciation and Specials

There are many different forms of media that present a “new race of humanity” coming to save the world with mutant powers. The most prominent of these series is Marvel’s X-Men, another is the Heroes TV show, first airing in 2006, which I have a much deeper knowledge of than X-Men. That being said, I will be focusing on Heroes in this case, but I believe my analysis here will easily apply to X-Men and other science fiction narratives. In this post I’m going to refer to people with powers as Specials. I will also discuss Specials and Humans as though they were already two separate species. So while reading understand that Humans are Homo sapiens and Specials are Homo specialus (or are they? Hopefully we’ll know by the end of this).

The biological species concept is probably the definition of a species that most people know and learned in school. It says that a species is a population of organisms that interbreed or could possibly interbreed and produce fertile offspring [1]. This definition has issues, such as what does “could possibly interbreed” even mean? If there is one group of cats on one side of a river and one group on the other could they still interbreed, even though there’s rushing water that’s impossible for them to cross in the way? Basically, it quickly becomes complicated.

There is another flaw in the biological species concept that is pretty large. Some animals can produce hybrids. A hybrid is an organism that has parents from two different species. The most well known example is that a horse and a donkey can have offspring, a mule. Mules are infertile so that isn’t a too complicated of problem, there will never be a mule that can mate with an other mule. . But some hybrids are fertile and can produce fertile offspring if they mate with one of the parent species [2]. Yet their parents are still considered two separate species.

There are other ways to define a species, such as the phylogenetic species concept, in which a species is the smallest grouping of organisms with a common ancestor [3]. However, this gets into questions on how you build a phylogenetic tree, what traits do you sort it by? One was to build a tree is to use DNA, and since we are talking about fictional hominids, DNA can’t be analyzed. So, despite its flaws, the biological species concept is going to have to do.

’m sure you’re confused and want to bash you head against the keyboard right now. Don’t worry. So do biologists.

So when putting Specials under the biological species concept several things come to light. First off Specials look like Humans; there is no physical way to tell them apart. This doesn’t mean they’re the same species but it’s important to note. So do Specials interbreed or have the possibility to interbreed? The answer is obviously “yes”. In Heroes: Micah, Peter, Nathan, and Claire are all offspring to two Specials. We don’t know if Micah, Peter, or Claire are fertile because they don’t have children (also Claire’s ability might affect her fertility). But Nathan has children so that means Specials are genetically stable enough to produce fertile offspring. Matt’s father is a Special but as far as the show has to say is mother was not, and he has a son, and he is obviously fertile. This means that if Specials are a separate species the event that caused the two groups to split genetically occurred fairly recently (more on this later).

A speciation event is an event that causes the two groups of organisms to not be able to interbreed anymore, for them to become two separate species. This can happen through several different methods.

  1. Allopatric: two populations are geographically isolated from each other by something like a mountain range or a river. These two groups cannot mate because there’s a freaking mountain in the way and over time they get different mutations and become different species.
  2. Peripatric: A small population is cut off from the larger population. This is also called “the bottle neck effect”. Usually some disaster like a flood happens and a very small isolated group survives. Because the population is so small when these few individuals mate some rare traits are expressed that weren’t in the original large population.  These unique recessive traits build up and they become a separate species.
  3. Parapatric: A species has a large range to the point that the populations on one end of the range have no contact with those on the other end. Over time the two groups on the extreme sides of the range become increasingly different and then become separate species.
  4. Sympatric: There is no geographic definition between the two groups when the speciation event happens.  This is extremely rare. An example is when Apple trees came to North America a small group of Maggot Flies, which normally live and mate in the Hawthorn plant, switched over to apples. The two trees grew next to each other and the Maggot Flies could move between plants. But over time those that lived on the apples became a separate species because they would only mate on apples, and the original species exclusively mated on hawthorns.

At the end of the day what is really important out of these four methods is that there is reproductive isolation. Group A cannot mate with Group B so they can become more and more different and then become two separate species.  This can be achieved by the two groups having different mating rituals or mate at different times of the day or year so they just don’t see each other, the two groups have sex organs that physically don’t fit, or the offspring of the two groups is infertile.

So looking at these methods have Specials and Humans actually experienced a Speciation event? Well Allopatric Speciation can be ruled out, Specials are found all over the world from Japan to New York so there is no magical valley that they all come from. There also hasn’t been a catastrophe that caused a Peritatric speciation. Unless of course it happened before the show, however that seems unlikely. Parapatric also seems unlikely because then it would be more likely that an ability would also be tied with a location, such as “every Special in Japan is a time traveler and every Special in New York has Empathic Mimicry”, which is not the case.  That leaves Sympatric speciation.

So then if there is a Sympatric speciation event (and there might not be) are the two groups sexually separated? Well Humans and Specials appear to have similar mating rituals. There is no reason to think they don’t. And Humans and Specials have sex organs that fit, there are several couples in the show where a Special and a Human have biologically related children. Finally the children of a Special and a Human is fertile (Matt is an example of this).

This means that there is no sexual separation between the two groups. At all. The sexual separation is extremely important, without it the group expressing the mutations (the Specials) will be reabsorbed back into the main group since the genes of the main group are most likely dominate over the smaller group that is branching off to form a new species. So for Specials to be their own species they would have to have no sexual interaction with Humans or their offspring with Humans would have to be infertile. Neither is the case.

So are Specials and Humans two separate species? Most likely no. There is no evidence of a speciation event and there is absolutely no sexual separation of the groups. However over a longer period of time, particularly if more and more Specials choose to have Special partners, they could become two separate species.

 

Breathing Under Water

Note: this was originally posted on my blog on tumblr.com. I have tried to convert some of the formatting over, however there may be some inconsistencies. Also this particular entry was written before I knew how to cite scientific sources, so sources will either be nonexistent or incorrectly cited. 

Alex, a fairly minor character in Heroes, has the ability to breath under water. And given how human anatomy works, he would definitely have pressure problems, but the exact opposite of someone who can fly. The show never shows how deep he can swim (I think we only ever see him use his ability in a pool which isn’t really that deep). But I’m going to assume he can go really deep, just to look at the most extreme case.

Deep sea animals are actually mostly made of water so they are less impacted by the pressure, thankfully humans are mostly water too so that’s not a problem. Some of these animals are actually mammals, like sperm whales. These are mostly diving animals that don’t actually live at the very bottom of the ocean, but can dive to extremely high pressures. As they dive deeper the sperm whale actually collapses its own lungs to adjust for the pressure, storing the oxygen in their muscles for the dive. Just like birds, sperm whales then use myoglobin instead of hemoglobin to bind the oxygen super efficient and allow it to move around the blood stream.

Continue reading “Breathing Under Water”

The Mechanics of Flying in Heroes

Note: this was originally posted on my blog on tumblr.com. I have tried to convert some of the formatting over, however there may be some inconsistencies. Also this particular entry was written before I knew how to cite scientific sources, so sources will either be nonexistent or incorrectly cited. 

Not only would a flier (someone who can fly) have to have amazing muscle control, they would also have to be adapted for low oxygen levels, low pressures, and other conditions that come with high elevations that humans usually aren’t exposed to and aren’t adapted to.

While a flier would have to have a lot of muscle to control their movements in their air, they would have to have a lighter skeleton than a normal person to make up for the weight of the muscles. In birds some bones are fused together while other bones are filled with holes or are even hollow to decrease the weight of the skeleton. So for a special to fly (at least at the elevation Nathan appears to fly maybe, different specials can fly at different heights) they would actually probably be lighter than expected for a person of their size. The drawback of this is that the person would probably have brittle bones, due to the hollow areas,  that would be easier to break than a normal human. However these hollow bones might be strategically placed, such as the ribs or some other area where a broken bone would not be lethal or prevent flight.

Continue reading “The Mechanics of Flying in Heroes”