Why "Zootopia" is Indeed Unique

Say what happened to the tunicates? Well the tunicate article is taking a bit longer than need be. So while we wait for that, here is a little intermission.

Something different for once. Aside from liking all things zoology I also happen to love animation. I grew up watching Chuck Jone's and Tex Avery's cartoons. Disney and Studio Ghibli of course was the thing for me, and Russian animation had a huge influence on me. Animation and zoology are my perfect combo. These two have come hand-in-hand for me as it helped me pay attention to details that help me distinguish certain animals, like a Cooper's Hawk from a Sharp-shinned Hawk.

Now as an artist and zoology student, I will say that I am not big fan of anthropomorphizing animals (even I had done some in the past) - biologically speaking it just would never work - something about a bird using its primaries as fingers to grasp objects, horses with fingers and toes and let us not forget of course the infamous human mammary breasts on various species. Now I know a lot of people enjoy anthropomorphic animals (or "furries" as they are sometimes called), but that is not my cup of tea.

When I heard the announcement of Disney's 55th animated feature Zootopia, there was one thing I could not understand. Disney advertise it as "unique" or "never seen before" in the sense that it is their first feature length to have anthropomorphic animals  Um, no, that is not true. If anything, Disney is known to make anthropomorphic animals which leads us to Robin Hood. Did Disney forget what they do?

I was still confused about this and imagine it is like any other furry creature feature. Until they released the first teaser trailer.

Oh my God. I finally see what they mean - it is unique indeed. One of things that I have noticed is that all of the anthropomorphic animals are mammals. Yep, there are no birds, no reptiles... just mammals. The premise seems like an alternative world where we did not evolved, and instead mammals took their place (it would be interesting to see if there are indeed other great apes in this world). Even more so, these mammals are all of terrestrial species (there could be some aquatic ones, though we shall wait and see). So it is like "Planet of the Terrestrial Mammals".

But what is even more exciting is that they actually applied science to this. Yes, science. They all have certain attributes that relates to their biology - the fox can see in the dark, the sloth is slow, gnu are major herding animals, rabbits hear very well. The anatomy - while human in nature - still goes along with mammalian biology. The rabbit is a female character, but she has no human-like mammaries (yes! No more creepy non-human animals with breasts!); the ungulate characters have human-like feet with big toe(hoof?)nails (the back limbs of ungulates are not double-kneed, but rather short legs with very long ankles and walk on their toes. The filmmakers are correct giving them big feet instead of walking on their toes, so yes!); the number of digits is accurate (the gnu has four, the fox and rabbit have five and the sloth has normal sloth-hands with three claws); lastly their body sizes matches their real-life counterparts.

This may not be a big deal but at least it something unique. If we look at Robin Hood as well as other anthropomorphic animal films, all of the animals were scaled to human-sized (for the most part), but have anatomical inaccuracies that I have mentioned earlier. Now yes there might be some arrows or quirks I will have (like the film saying "animals = mammals" which is not), but I am really excited to see this :D

Reptilia? Sauropsida? Diapsida? Sauria?

Komodo Dragon and Hoatzin. Photo by Thore Noernberg. 

During my sophomore year in college I was fortunate enough to have two professors that had their preference for their “ideal” taxonomy and their reasonings behind it. My vertebrate professor loved cladistics. She explained to the class in a lecture once that cladistics is ideal as life is one, big evolutionary saga where lineages (even species) are potentially one and the same. It is all about the last common ancestor. My anatomy professor prefer the traditional Linnaean system, where organisms were classified based on shared morphological traits and there is ranking involved. To her, cladistics can be "rather clunky” and potentially confusing but my vertebrate professor found ranking of organisms is rather silly. They did both agree that it was important to categorize organisms based on relationships - the monophyletic clade the ideal group which biologists love. While most of my peers find taxonomy and systematics to be trivial and a nightmare to study, I find them to be quite enjoyable and also important in understanding not just how organism lineages came to be but also how nature had selected certain behaviors and anatomical features that are best fit for reproduction for a species. I strongly agree we need to categorize organisms into monophyletic clades and I can understand why both of my professors have chosen their prefer taxonomy system. Of course then you have people like Colin Tudge (2000) and Robert Bakker (1986) that tries to combine the best of cladistics and Linnaean taxonomy (known as “Neo-Linnaean”), but that is a whole other animal and one that can be very flawed. More so - in my opinion - than both cladistics and the Linnaean system! Indeed the chose of the taxonomic system that scientists use can affect the way we see the relationship of species. A classic group that beautifully illustrates the point are the reptiles and the birds.

Taxonomic Segregation

Despite the overwhelmingly amount of evidence and the obvious that birds are reptiles, majority of major herpetological and ornithological organizations (as well as some books, particularly field guides) still place reptiles and birds into two separate clades Class Reptilia and Class Aves respectfully. I have yet to see a field guide to birds and reptiles of North America being placed in the same clade together. Even more so there are still people that cannot quite see how birds are reptiles, even though feathers and reptile scales are homologous structures made of keratin, same type of blood, and most important of all molecular and morphological work has shown a close relationship between birds and crocodilians. The problem stems from the fact that in the Linnaean system, a class cannot be in a class. Classes can be sister taxa but that is it and nothing else. It is a paradox for it is not the fact that the world’s ornithologists and herpetologists do not acknowledge this relationship. On the contrary, these majority of these scientists do support the recognition of birds being “glorified reptiles” it is just they prefer the less clunky route. If they are so focused on updating evolutionary relationships (and they do. Taxonomy changes amongst scientists is a vicious, political game. But here is not to discuss that.), then they would lump. General biologists and paleontologists do a good job in placing birds and reptiles in the same clade that could regard as a class. If one were to simply follow the cladistic approach you are truly not only finally acknowledging the evolutionary relationship on paper at these meetings, but you are also helping eliminate “how birds are reptiles” from the public and educate them to understand the closeness. This will end taxonomic segregation.

Divide Reptilia! Wait, No!

This class, according to the cladistic approach, would be the most speciose and successful of all the terrestrial vertebrates, colonizing every single corner on the planet. It would have about 20,808 species worldwide, from the Tuatara to passerines. But what should the name of this class be? You would think that the name for the class would be Reptilia, given the argument that name of ancestral lineages has priority over daughter lineages (a classic example would be when the then Order Pinnipedia was found out to be nested in the Order Carnivora. Pinnipeds are now seen as members of the Order Carnivora). But there is a problem. Some cladistic scientists have argued that the general concept of Class Reptilia is extremely invalid for it is pretty much a synonym of Amniota (Tudge, 2000); stem-mammals (“synapsids”) were originally classified as members of Class Reptilia, but majority of work today suggests they have diverge before true reptiles, adding more fuel to the invalidity of Reptilia. Lastly the most common argument is Class Reptilia did not intended on including the clades Class Aves and Class Mammalia. This left two options. One option by the Neo-Linnaeanists was to make Lepidosauria, Testudinata and Archosauria as classes, which Baker (1986) advocated very much so in his book The Dinosaur Heresies. Other scientists and myself disagree with this. It is redundant and would create confusion in regards to the many fossil reptiles that do not fall within any of these three groups. The second option was of course giving a new name. The name cladistic taxonomists use is Sauropsida.

Class Sauropsida? Or How About Class Diapsida?

This diagram is Reptilia vs. Sauropsida. Diagram by Petter Bøckman

Sauropsida does seem to be a good name. It is define to include the last common ancestor of reptiles, including birds which they most closely related to crocodilians. So not only it is good, but it is also valid as well. However I do have to detest. I never truly see Sauropsida as something as class worthy. Rather I see it as more of a stem-branching that contains stem and crowned animals just as how most scientists view Synapsida. Synapsids contain both stem-mammals and crowned-mammals. I can make an argument that Sauropsida is a stem-branching as it contain both stem-reptiles and crowned-reptiles. Indeed this thought probably never occur as for a while there was a possibility that turtles might be the last, surviving anapsids on the planet. It has become very clear that turtles are definitely diapsids and the definition of a crowned-group is it must contain extant members. Therefore, the anapsids of Parareptilia are not crowned-reptiles as well as the earliest sauropsids and even the early eureptiles in my opinion. Not to mention that all my professors prefer Reptilia over Sauropsida as they feel you can simply redefine the definition and its membership - see Modesto & Anderson (2004) as well for more reading. An old name are better to keep than make a new one, as new names can be redundant to make. Of course this would not eliminate the whole Amniota issue and I would still think Reptilia as a stem-branching group. So if not Reptilia or Sauropsida, then what would be a prefer name for a class of reptiles and birds in a field guide concerning them? Diapsida? Possible, since molecular data has shown all reptiles and birds are descended from a diapsid ancestor (Crawford et. al, 2015). However there are diapsids that fall outside a lineage consisting the lepidosaurs, turtles and archosaurs. They would be stem-reptiles still. So scratch that one off the list. All might seem to be lost. There is, however, one I have found and I actually prefer.

Class Sauria?

Sauria was originally intended as a suborder containing the lizards in Order Squamata. Of course, the name has fallen out of use and is almost obsolete. However I have seen the name a couple of times in some papers, with at least one paper using Sauria as a clade containing the lepidosaurs, turtles and archosaurs and their stem representatives (Crawford et. al, 2014). Sauria would be/is the ideal name for a class. Sauria can be defined as a crown-based grouping for it contains extant members which are our modern day reptiles and birds. The interrelationships among reptiles and birds is still the same, is not at risk of being the same thing as Amniota and it can be use for the designation of class (we would still have the problem of making classes for stem-reptiles, but we have to look at the context for our modern species. Not to mention I feel as if we are coming to a point where “crowned” can equal to a Linnaean ranking, such as crowned-mammals being in the clade Class Mammalia). Lastly we can collectively call reptiles and birds as “saurians”. In short the name of a single clade containing reptiles and birds is ideally Class Sauria. I don’t have high hopes for this catching on, but I do hope someone would also come to the same conclusion as I have. I would love it in the near future to see book stores selling field guides of saurians of North America. Such a thought might cause herpetology to fully divide into batrachology (the science and study of amphibians) and a new field that might merge with ornithology. Perhaps “saurology” and the birth of major saurological organizations and parties?

Birds being a Single Clade Order

Self explanatory; crocs and Tuatara make up 0.02%! Based on the Reptile Database and TiF.

Despite not being the main focus of the article, there is something that also needs to be address as well. How many orders would there be in Sauria? The number of reptile orders is not the issue, it is the number of bird orders. Should Sauria have a total number of at least 50 orders? In my mind that is a bit excessive. Not to mention birds as a group are just as diverse as the squamates, yet I find nobody arguing or suggesting splitting the squamates up into several different orders. One could make an argument that birds are actually a pretty much a homogenized group with feathers, a beaked head and bipedal. Of course bird species do vary in these attributes, but so do various insect orders such as beetles. And for a single order to contain 10,000 species would not be an issue. After all, squamates approach at least 9,000 species. What would the name of the order be? Since birds are descended from theropods and defined as such, it would be Order Saurischia. Under this argument, crocodilians might have a similar predicament as they are descended from rauisuchians (Nesbitt, 2011) so therefore the clade is Order Rauisuchia, not Order Crocodylia. This does not mean we have to call them “saurischians and rauisuchians” from now. We can still call them "birds and crocodylians” as they used much more in everyday usage in regards to modern species. But that is only a suggestion of mine. Still, we need future scientists to finally end the coffin to Reptilia and Aves and bring out Sauria.

References

• Bakker, R. T. (1986). The Dinosaur Heresies: New Theories Unlocking The Mystery of the Dinosaurs and Their Extinction. William Morrow, 165 p.
• Crawford, N. G., et. al. (2015). A phylogenomic analysis of turtles. Molecular phylogenetics and evolution, 83, 250-257.
• Modesto, S. P., & Anderson, J. S. (2004). The phylogenetic definition of Reptilia. Systematic biology, 53(5), 815-821.
• Nesbitt, S. J. (2011). The early evolution of archosaurs: relationships and the origin of major clades. Bulletin of the American Museum of Natural History, 1-292.
• Tudge, C. (2000). The Variety of Life. Oxford: Oxford University Press, 407-410. 

Common, Boring Species can be Cool Too!

For my ornithology class we had a midterm paper that was a species account. We could choose any species we wanted and we would also have to present to the class. Of course most of us in the class have chosen charismatic, exotic or endangered species. Only one of my friends has chosen a common, everyday bird we see the Eastern Bluebird (Sialia sialis). Once we were done with the assignment and the presentations, my professor had made an interesting comment.

Male Eastern Bluebird (Sialia sialis). Photo by William H. Majoros 

His comment was that he does not understand why in the years he has been teaching, none of the students he has taught usually never a "common" or "boring" species like a House Sparrow (Passer domesticus), a European Starling (Sturnus vulgaris) and/or the American Robin (Turdus migratorius). While he understood the attraction of exotic/rare/endangered/charismatic species in all vertebrate sciences, my professor made a interesting point in that more common and everyday species are just as complex and exciting to research with. He went further saying how meticulous European Starlings are when it comes to foraging in a flock where each individual has their own space. Or how House Sparrows peck baby bluebirds to death by putting a hole in their skull, or the different dialects of American Robins.

I never really have thought about this before but once he mentioned it I have been thinking about this ever since. Indeed science is a never ending space of knowledge. Sometimes we might be surprised in what we find in common species that was never seen before. For example domesticated cattle or even deer would consume bird nests containing young (Furness, 1988 and Nack & Ribic, 2005) or the complex coevolution between humans and dogs (Schleidt, 2003). In fact domesticated (or at least those we keep as pets) animals in general are just as fascinating as their wild relatives (if not, more!); sometimes majority of the information of the biology, evolution, development and the behavior of our vertebrates comes from mostly common animals (such as lab rodents, chickens, Zebra Finches, catfish). They can even warn us about the state of the planet; if a common everyday species like the Red-winged Blackbird is all of sudden declining in the overall population, that is something to be concern about (Blackwell & Dolbeer, 2001). That is why students and friends in my school often choose to work on more common species for not only the connivence but also the potential data we can obtain!

In essence it goes to show that every species - no matter what they are - are important for not only preserving biodiversity but also for research as well!

References

• Blackwell, B. F., & Dolbeer, R. A. (2001). Decline of the red-winged blackbird population in Ohio correlated to changes in agriculture (1965-1996). The Journal of wildlife management, 661-667.
• Furness, R. W. 1988. Predation on ground-nesting seabirds by island populations of red deer Cervus elaphus and sheep Ovis. Journal of Zoology 216, 565-573.
• Nack, J. L. & Ribic, C. A. 2005. Apparent predation by cattle at grassland bird nests. The Wilson Bulletin 117, 56-62.
• Schleidt, W. M., & Shalter, M. D. (2003). Co-evolution of humans and canids. Evol. Cogn, 9, 57-72. 

What Happen to Learning about Anatomy?

Something a bit different today and this is what I have noticed at my zoology classes. I don’t know if it is something due to with the classes being more or less introductory courses, or it is the professor that sets up the class, but I am surprised with the lack of material that concerns on anatomy. I mean, sure in the vertebrate zoology class and in the ornithology course the professors had talked to some detailed about major, unique features in vertebrates. Yes I know there is so much to know in a semester worth of class. And yes, sometimes the professor is more comfortable in the ecology and evolution of the groups they are experts on as opposed to the anatomy.

The reason I bring this up is in my spring semester when I was a sophomore, I took a comparative anatomy class. Before hand I knew this would probably be the hardest zoology class I will ever take, as I am only aware of the basics of the vertebrate anatomy. Sure enough it was a hard class, but it was still interesting and I have learned things I had not before. Not to mention it also shows just how unique lobe-finned fish and mammals are (the theme for the class was mostly the evolution of crowned mammals, with lobe-finned fish being the starting point). What made it hard was the lack of a good, up-to-date vertebrate anatomy textbook. The one we had was a dated 5th edition of Analysis of the Vertebrate Structure by Milton Hildebrand and George Goslow. The book was fine, although it was heavily Linnaean in its taxonomy, lack of good pictures and the professor noted some “errors” in the book she found. Not to mention that, instead of the chapters being center on the various chordate or vertebrate groups, the chapters are instead based on the various body systems. Which is maybe fine for some people but it became very disorienting for me.

Despite the flaws, it is still a decent book. Though be warn of scaly, cold-blood dinosaurs. Photo by Wiley Press.

As a result whenever I had to study for the class exams, I would find myself going to the library and reading the anatomy chapters in the ichthyology, herpetology and mammalogy textbooks instead of the textbook for the anatomy class. I guess in a way it actually helped me be a better researcher and taking notes in a field I was not aware of. But what is the point in having a textbook that does not do the job that you need it? So I began to search for a better vertebrate anatomy textbook. But as I search for such a textbook, I discovered that there was no books that are better than the textbook for my anatomy class in the library. None online either. I guess most of the anatomy that is covered in the various vertebrate or chordate groups can be find in those specific textbooks I have used instead. Perhaps one day there will be a book suited to more of my liking. Here are my three suggestions for the ideal anatomy book (if you happen to find such book, or a good vertebrate/chordate anatomy textbooks, feel free to comment them below!):

1. Have the book be up-to-date and use cladistics. Life is no longer just categories or rankings, but one huge whole of the same coin.
2. Chapters on clades or groups (for example, chapter one will be on lancelets, tunicates, lampreys and hagfish, chapter two on cartilaginous fishes, and so forth), and not on the body systems. Quicker and faster to look up and obtain the information needed.
3. Very good and highly detailed drawings and photographs. Anatomy can be pretty complex or overwhelming to learn for a beginner.

Of course there will still be the issue of the lack of depth in anatomy in class. Indeed even some of the newer textbooks for the various vertebrate sciences seem to be cutting down the information about anatomy and not as in-depth as it was in the older textbooks that I have read in the library. We should not briefly glance over anatomy. We should still study it extensively as it still has implication in the evolution, the ecology and the conversation even to help species. But we also must make it in a more coherent manner, one that will not scare away students who are not familiar with anatomy. For this to be successful there must be cooperation between the education industry, the professors and the students for this to happen.