12. 2017-July-25 Comps Day 2- Mitchell
Open notes, open book, full access to internet.
1) Peppered Moths and Bombardier Beetles are iconic examples of evolution in action, and have been used by both creationists and scientists to support their arguments. Evaluate the status of either or both of these prominent stories, including recent findings. This includes both primary scientific literature, popular writing, and creationist screeds. The goal here is for you to demonstrate a deep understanding of the biology of how these systems evolved, and how the public perceives them, What do you think are the major areas of this topic that need further scientific or pedagogical investigation?
2) Explaining and communicating complicated ideas to the general public is difficult. Please outline a public outreach activity/publication concerning current scientific understanding of a complicated or difficult topic that is NOT in your primary focus area of Evolution (for example, human population growth. Your writeup should include: The topic you will consider, the key aspects of the topic for your purposes, your audience, and what is complicated about topic - why is it hard to convey or what is hard about it. You are free to choose any medium/method/approach to do this, including white paper, museum exhibit, 3-d interactive videogame, etc. Explain your choice of medium (or media). What learning outcomes do you think are most important for this topic? What common misconceptions do you anticipate, and how will you deal with them?
3) There is a growing literature on communicating scientific information to the public, and you should be keeping up with it. Please write a concise but insightful assessment of the historic state of this field at the end of the 20th century- the major principles, approaches, and philosophical and empirical bases used to guide the field up to that point. Then explain more recent developments since that time that are important, valuable, or intriguing (and why you consider them noteworthy). This might include an explanation of a few of the most recent "hot topics", or perhaps of broader developments. You have considerable latitude here to use this as an opportunity to demonstrate that you are well acquainted with the historical and current understanding of how to communicate scientific information and improve scientific literacy.
4) Choose a topic not part of your personal research that you have been following in the recent scientific literature. Write a brief summary of the major issues concerning this topic, and then propose a way to bring an IB approach to it. The idea is to connect disparate ideas to one another in a new way to better understand the topic. What new perspectives does the IB approach bring to the combined topics? Feel free to comment on the value and limitations of this sort of approach.
Wow. When Joel emailed me this one, I looked at my phone, and I had a solid ten minute of sheer terror. LOOK AT THOSE QUESTIONS. So I made a point of calling my mother to talk myself down from the edge of the existential cliff that is facing down four questions you don't quite feel prepared for, talked out which ones would be easy, which would be hard, and started working on them in order. Surprisingly, after the first one.. THEY WERE ALL HARD. Luckily I managed to knowck out the second one surprisingly quickly, which gave me some leisure to go get lunch downtown (a garden burger and salad), chat with the bartender (the word of the day was "frantic"), and then head back to keep working on the third and fourth questions. The last question was, frankly, horrifying. But luckily I had in my back pocket my works here in The Deep, so I was able to pull on my elephantexpertise to take care of things.
So far, I've learned some really interesting things about comprehensive exams, and to some extent, myself. The questions I've been hit with so far have been really challenging. And I have to emphasize that word. Challenging. I honestly have never felt so challenged in my entire life, and it's exhilirating. I honestly must compare it to experiences I've never had, like taking a plane up to go skydiving, or a boat out to go diving off of the great barrier reef (RIP). I can see the edges of my knowledge, and I can feel myself being pushed off them. The demands of comprehensive exams are fascinating. I'm being asked curveball questions deliberately, to probe my core and see my weak spots, not only so my committee members can see, but so I can see as well. In both of my exams so far, I've been faced with questions along the line of "Discuss the historical state of suchandsuch a field" and I've deflected as hard as I can from those sorts of questions. I'm a fan of history, but not so much science history, from the perspective of a scientist. I never think about Darwin (I do occasionally ponder Mendel); I can't stand the cults of personality, this sense of identity people take in thinking a scientist is cool, or even important. As an active learner, I am far more interested in what we know, than necessarily how we came to know it. And this might end up biting me in the ass. So far two of my five committee members have directly asked about the history of the fields I'm working in, and I have not really pulled it off. I'm under pressure to not only write about things I'm not extraordinarily familiar with, but I have to do so while under a time limit, which is utterly amazing to have to deal with. The quality of writing I'm doing right now is really terrible, but when you're under an eight (or less) hour time crunch, you only have time for a single draft.
So, without further ado:
1. Bombardier beetles have an iconically complex evolutionary narrative underlying their biochemically explosive defensive secretion, and have been held up by creationists as evidence of intelligent design. Historically, creationists utilized a translation of the a paper (Schildknecht & Holoubek, 1961) describing the bombardier beetle’s discharge mechanism as the grounds for their argument that such a structure could not have occurred without intelligent design (Gish, 1977). Gish believed that the hydrogen peroxide and hydroquinones produced would normally be explosively reactive, and are kept inert in the bombardier glands through the use of an inhibitor which would then be negated by the presence of catalase. They were, unsurprisingly, working under misconceptions as to the nature of the biochemistry occurring within the bombardier pygidial glands. Gish and others would continued to use this admittedly (Kofahl, 1981) sloppy mistranslation well into the 90s (Gish, 1977, 1993; Hitching, 1982, Huse, 1993), despite the fact that as early as 1964 (Schildknecht et al.) had published an article in English which clearly described the mechanisms at hand. Bombardier beetles produce their defensive spray by a series of chemical and biochemical reactions.
Hydroquinones (Hydroquinone and Methylhydroquinone) and Hydrogen peroxide are secreted as an aqueous solution into the reservoir of the gland. They are then pumped into a reaction chamber containing catalases and peroxidase. The peroxidase catalyze the oxidation of the hydroquinones into quinone and hydrogen gas, while the catalases break the Hydrogen peroxide into water and Oxygen. The oxygen and hydrogen then react producing water, which is exothermic enough to flash vaporize a portion of the liquid within the reaction chamber, ejecting the quinone, itself an irritant, at both high speeds and temperatures (Aneshansley et al, 1969). The precise nature of these mechanisms, including the pressure-sealed valve connecting the reservoir and reaction chamber, allowing for the rapid explosive release and reentry of more fuel into the reaction chamber for a pulsing fire at a rate of over 500 pulses per second, and the cuticular developments that buttress the reaction chamber against the high pressure reactions, have been further elaborated in numerous papers (Eisner et al, 2000; Arndt et al, 2015; , including, rather surprisingly, an article from the Journal of Creation (Armitage & Mullisen, 2003), which serves as a rather unexpectedly robust survey of the literature on both sides of the debate.
However, creationists frequently utilize an argument of complexity as evidence for their disbelief in the evolutionary process. This is compounded in part due to a central element of modern creationist dogma necessitates that organisms do not increase in complexity (due to The Fall), and that mutations (in a somewhat deliberate misunderstanding of the process) can only lead to loss of fitness. As such, they consider that complexity in and of itself indicative of design, as opposed to possible evolutionary processes. So, in spite of the increasing explanatory power of our understanding of the bombardier beetle’s physiological/morphological/biochemical workings, the sheer “complexity” of it continues to be considered “evidence” but creationists. The nature of a complex bioreactor producing an exothermic explosion to propel liquids in a targeted fashion seems to be far too complex to have arisen stepwise from evolutionary processes. A conclusion which , as one author describes, “merely admitting ... little ability in problem solving.”
Studies of a beetle of a closely related outgroup, Metrius contractus, have shown that these sisters to the bombardier beetles also produce a hot hydroquinone mist, but it is produced as a froth rather than a directed jet-like pulse (Eisner et al, 2000), and hydrogen peroxide is used similarly in other glands to generate a heat facilitated secretion of compounds. It becomes rapidly apparent that a cursory examination of bombardier beetles and their closest relatives that the “complexity” described as overwhelmingly impossible for natural selection to produce is in fact rather straightforward provided the application of some critical thinking and phylogenetic analysis. Despite the improved understanding in the scientific and even some creationist literature (Armitage & Mullisen, 2003), misunderstandings of the basic biochemical mechanisms of the bombardier beetles’ spray persist in creationist literature (Catchpoole, 2005) even after revisions (Anonymous, 1989).
What becomes resoundingly clear is that there is a conjunction of general scientific misunderstanding of evolutionary processes (and even basic biology) and dogmatic opposition to science that goes against creationist (and particularly young earth creationist) dogma. A major challenge becomes addressing misconceptions that have become embedded in public perception, even more so when they are supported or reinforced by “incontrovertible” religious beliefs. Further work is needed to better illuminate for the public the larger scale mechanisms (most notably the findings and concepts of evolutionary developmental biology) in order to streamline the presentation/argument of the biological underpinnings of the evolution of “complexity”.
2. Genetic engineering, and particularly Genetically modified organisms, are a highly controversial topic, particularly in public perception, in part due to broad misunderstandings of the nature of what genetic modification entails, which is further exacerbated by simple lack of knowledge of basic genetics. The central dogma of genetics, namely that DNA is transcribed into RNA, which is in turn translated into protein, is descriptively simple, but conceptually complex, most notably in the nature of protein production is not intrinsically intuitive to lay audiences. The nature of codons as a basic unit for interpretation by ribosomes to produce protein chains, and even the basic nature of proteins as being elaborately folded linear chains (or complexes of such chains), is frequently non-obvious information. Thus, in order to begin to address public misconceptions of the nature of GMOs (and perhaps more importantly, the actual ethical implications, in contrast to the “health” reasons most commonly touted), the fundamentals of genetics must also be addressed, namely how DNA encodes proteins, which then are in turn the enzymes, structures, and signals which can produce, constitute, and interact with all other components of a living organism.
The key aspects are:
The nature of proteins in all forms of life (structural, enzymatic, signalling)
Central dogma (the concept, but not process, of codon translation into chains of amino acids, and protein folding)
Extant examples of genetic engineering (biotechnology, artificial selection, transfection)
The non-nebulous state of protein-encoding genes (can’t produce “toxins”)
Real possible ethical and environmental repercussions of GMOs
These misconceptions regarding GMOs typically involve the belief that their use can have unexpected side products, typically described as potential “toxins”, which could cause unforeseen health effects in consumers. This misconception is particularly baffling when one begins to consider the huge amount of artificial selection human civilizations have been involved in for millennia, as well as the active use of genetic engineering in biotechnology and other non-agricultural contexts; highlighting these examples of genetic modifications already present, in conjunction with a deemphasis on the “good vs bad” dichotomy of natural vs “unnatural”, could help to diminish these misunderstandings. Establishing the factual nature of genetics can serve to distance it from this pseudo-ethical division, and simultaneously provide information that would support improved scientific literacy. It would seem that many of the stigmas held towards GMOs are due to ignorance of its mechanisms and methodology, as well and the nature of genetics itself, particularly in the face of vocal minority opposition. Clearly the misunderstanding of GMOs can be better addressed by emphasizing the way genetic engineering in all its forms (whether by artificial selection, bioengineering, or transfection) functions both naturally and artificially to explain away the misconceptions of possible toxic outcomes of genetic translation into protein. While there are certainly ethical repercussions of GMOs that are distinct from the biochemistry, these topics should be kept separate from the basic biological information which must be conveyed for understanding, to better discourage misreading of the didactic content.
This topic is best addressed in the context of demographics who have to make informed decisions regarding science policy (eg., are scientifically literate) and so a good target audience would be the broad range of free-choice learners who patronize museums, supplemented with the use of public talks/workshops and white papers. Museums are well established institutions for informal education, and people who visit them are typically driven by a number of motivations, several of which (Falk, 2009) are explicitly curiosity- and learning-driven. Museum settings allow for the development of multiple thematically connected interactive(physically and mentally)/participatory exhibits to engage audiences, allowing each individual aspect of this topic to be addressed within overlapping thematic units, with explicit indicators to allow for audiences to connect each component to one another. Presentations and White Papers provide additional means for audiences to access information, allowing for persons of different learning styles to select their means of gaining knowledge. Where the free structure of exhibits appeals to many, the formal structure of a talk or series of talks can appeal to certain demographics, and written reports in the form of a white paper can be accessible to those who are unable or unwilling to travel to a museum or other site to learn (or simply prefer to read rather than be lectured).
A major challenge in education settings is both the establishment and accomplishment of set learning outcomes. In informal environments, this is further transformed by the additional layer of interpretation between the experts/designers of an exhibit and the perception/expectation of visitors. Research has shown that teaching using abstractions of processes can be vitally useful for their transposition to similar but disparate contexts, but at the same time the use of metaphor and analogy without explicitly illuminating their usage can lead to learner confusion, and further misconceptions. Both the informal setting of a museum exhibit as well as the nonformal media of talks and papers allow for the utilization of the 5e instructional model which can help to address these problems through it’s semi-reiterative design.
The Biological Sciences Curriculum Study (BSCS) 5e model has been in use in formal settings since the late 1980’s (Bybee et al 2006). It directly utilizes the the developed knowledge of the contextual model of learning. It consists of five steps:
Engagement, allowing the instructor (or in this case, students themselves) to directly assess the preexisting knowledge, conceptions, and contexts.
Exploration allows for relatively self-guided, competence-supporting activities interacting with the subject being worked with (initial interactions in an exhibit).
Explanation, where the concepts at hand are made explicit by the instructor, working from the previous steps (clear, concise, highly-visible pedagogical materials.)
Elaboration then revisits the concepts and exercises of the Exploration stage, now incorporating the new information from the Explanation phase to better reinforce understanding
Evaluation, wherein the didactic content is reviewed and emphasized, and the expected takeaways are made explicit.
Even in informal, uninstructed settings, the 5es provide a clear framework of exhibit design, enabling explicit learning outcomes and a deliberate effort to highlight misconceptions and preexisting knowledge. As museum exhibits, especially series of exhibits, allow for non-linear exploration, visitors of varying backgrounds and advance to exhibits that address their concerns and curiosity, which facilitates a sense of control and competence that contributes towards self-motivated learning (Self-Determination Theory, Deci & Ryan, 1985).
The key learning outcomes of this combination of exhibit and workshop/paper would be
What proteins can do
How DNA encodes Proteins (Central Dogma)
How genes can be moved between genomes in nature
Current real topical issues relating to GMOs
Again, by nestling the topic of GMOs into a broader suite of general principles of biochemistry and genetics, while simultaneously deemphasizing some of the minute mechanistic details (the process of transcription, the elaborate processes of the ribosome), can allow for audiences to engage with a topic at multiple levels of complexity, allowing for interested participants to improve their knowledge and understanding of a topical, and frequently controversial subject in biology.
3. The president of the American Association for the Advancement of Science issued a call for a new social contract for science (Lubchenko, 1998), one involving a new role for scientists in public discourse. Bazzaz et al. (1998) remarked, “. . . good science consisted of two basic activities: (i) doing first-rate research and (ii) publishing it in the technical literature for the benefit of scientific colleagues. We firmly believe that a third activity must now be added by all scientists: (iii) informing the general public (and, especially, taxpayers) of the relevance and importance of our work. We are convinced that this applies to even the most esoteric of “basic” research, because understanding how the world works is fundamental to both satisfying natural human curiosity and solving the human predicament.” These remarks at the end of the millennium are indicative of the rather recent recognition of the need for scientific literacy in modern society, especially as it pertains to increasingly complex policy decisions; more telling, perhaps, is that this coincided with the recognition that the responsibility of science communication, to bridge the gap between scientists and laypeople was a task which fell on the shoulders of scientists themselves.
An ongoing challenge in science communication is this gap, especially as it requires translation from the practical scientific literacy, or true scientific literacy (Shamos, 1995) of scientists to the civic scientific literacy: a level of understanding of scientific terms and constructs sufficient to read a daily newspaper or magazine and to understand the essence of competing arguments on a given dispute or controversy (Shen, 1975). This division reveals itself in the mindset of some scientists who view that science policy and decisions are impenetrable to citizens, and are best left to be performed within a technocratic framework, ignoring the general opposition of society to decisions being made outside of a democratic process (Miller, 1998). This highlights the discrepancy between the degree of technical expertise scientists must have with the general lack of such knowledge in the public audience. Scientists frequently cannot accurately gauge what it is like to not be heavily trained in a subject, while nonscientists frequently cannot gauge what it is like. Thus, while lay audiences frequently perceive scientists as being distant and often elitist, scientists frequently reflect this by their perception of audiences as being uneducated/uninformed. Only now is it becoming more and more apparent to scientists that communicating science to audiences is best accomplished by scientists themselves, who have taken efforts to recognize, understand, and adapt to this asymmetrical division. One of the greatest difficulties in establishing science literacy and effective science communication is often the nebulous means by which success in such efforts can be measured. Frequently learning is heavily personalized and contextualized based on prior knowledge and experience; most learning that occurs is built upon established knowledge, reinforcing and expanding it, rather than introducing entirely novel concepts. These mental models shape how individuals view the world, and shifting them requires extensive effort both in highlighting misconceptions, presenting novel models, and supplying ready feedback and support through the resulting cognitive dissonance.
This need for science communication from scientists is especially needed when the other major sources of science information are examined. A number of studies have shown that media, particularly television, are the primary source of science information regarding global climate change, one of the, if not the most important contemporary scientific field for policy decision making on an international scale (Bell, 1994; Wilson, 1995). This becomes problematic when science journalism not only suffers from more errors than general news (Tankard & Ryan, 1996), but also that the majority of science journalists’ obtain their information not from scientists, but in fact other journalists (Wilson, 2000), contributing to a circular “news ‘food chain’” (Trumbo, 1996), where misunderstandings, inaccuracies, and blatant information can get traction. This is a particularly troubling observation considering its age, in light of the current state of news cycles and the growing concept of “fake news” becoming worryingly real in current news and “journalism”.
By 2000, it was perceived within the museum community that the popularity and functionality of museums was on the rise (Falk & Dierking, 2000), in part due to the growing concept of science, and the enjoyment of science, as an identity distinct from the identity of being a scientist. Between science centers and museums, children’s museums, natural history museums, and botanic and zoological gardens, a broad range of topics targeting wide audiences are presented in an informal, free-choice context. For many, these sorts of institutions are the primary source of science education outside of classes, and the value of them continues to be developed and evaluated; outside of these places, news and articles on scientific topics remain too sensational, technical, or abstract to facilitate connections to personal contexts and narratives, which renders many of them ineffective (Spranger, 1989). It is an ongoing challenge to design, build, and present means of science communication that not only effectively describe the concepts at hand, but do so in a way that enables citizens to engage with them and understand them at the personal level that is needed for productive, informed decisions to be made.
Currently, major opposition to a number of elements of scientific literacy, particularly those relating to historical sciences such as geology, evolutionary biology, and astronomy comes from religious fundamentalism which holds sway across the international landscape, which serves as an entirely distinct hurdle from the basic challenge of understanding scientific topics. Work must be done on addressing (combatting, even), the dogmatic anti-science arguments being used, and this results in far more difficulty than merely addressing unintended misconceptions. Due to the scale of major components of scientific literacy, the concepts and processes must be presented in an as accessible (and accurate) means possible to promote not merely understanding, but engagement with learning. While informal education has classically focused on museums and other like institutions, the advent (who am I kidding, it’s been nearly twenty years), of internet-based exploration and learning has opened (and in some cases, as we’ll see, reopened) gateways to novel means to engage audiences and convey information.
Historically, games have been used as tools of play, and as tools of learning. Games such as Chess, Shogi, Go, and others were used by numerous cultures to illustrate the nature of strategy, and educate future political and military leaders for their more complex real world analogs. In the modern day, serious games, typically used by the world’s armed forces for training, are a prime example of using games to present material in novel ways outside of traditional formal education structures. In the past decade the trend of “gamification” has taken the business world by storm, and has provided inroads for the development of gameful systems for purposes beyond play, to convey complex concepts in abstracted, understandable presentations, and especially to motivate (for better or for worse) desired behaviors.
Games can easily convey concepts that when presented purely as ideas or sets of facts may be difficult to grasp, and do so in a way that will produce sufficient engagement with their audiences for sufficient amounts of time that either their understanding of the concepts contained makes the game no longer interesting (in which case the educational component has succeeded in its task, and the game is no longer useful: this is not a bad thing), or their improving grasp of the processes involved allow for more nuanced play, and as such more nuanced understanding of the topics being presented. Even in games without explicit didactic content, probability and arithmetic are presented extraordinarily effectively, and the structures of games allow for the manipulation of the intrinsic probabilities of game outcomes in such a way that they can be used as simulacra of almost any numerically driven concepts.
Thusly, games purpose built with didactic framing and content can prove even more effective at conveying ideas to players passively as the players actively participate in the game. Beyond such simple mechanics as using dice or decks of cards as random number generators (RNGs), interactions with player decisions and actions allow for comprehension, even in a somewhat complex system, of the direct cause and effect relationships of multi-faceted interactions. The field, whatever it may be called when the dust clears, of game-based education (research), both analog and digital, shows great promise in utilizing the elements of play that make games both engaging and enriching to leverage learning and understanding of complex topics. This is particularly valuable as studies have shown that student backgrounds have limited influence on learning outcomes (Diehl, 1991), which allows for mixed groups of learners to engage with this medium of education. A small number of commercially published educational games currently exist in the public sphere (Eisenack, 2012; Kwok, 2017), and few of them have been explicitly studied for their effectiveness in science education. Current research has focused primarily on basic design principles, which, while new in academic literature, tend to simply be reinventions of wheels made in the game design industry, or gamification, which differs significantly from game design in its application by definition (there is some disagreement on these nuances), to non-game contexts (Deterding et al. 2011).
Between education game design and the continuing development of exhibits and practices in informal institutions, and the ongoing growth of science communication by scientists, a number of somewhat independent (but in truth, heavily interwoven) means are growing and expanding to bridge the gaps between scientists and nonscientists.
4. First some levity:
As my last question of the day, having arrived at it with more than its fair share of allocated time available, I stared at the question, printed in large font on a sheet of paper in front of me, for a while, slightly confounded. I naturally did what any person of my age (am I a millennial? I suppose that doesn’t matter) would do, I hopped on my phone and texted my friends about how this last prompt was a doozy. A friend of mine jokingly suggested the answer, “I don’t follow anything that’s not my research. The IB approach to fixing this would be talking to other people in IB.” I found this entertaining, but luckily I do in fact follow other things in the literature. Another suggested “Why don’t you just spin your old research?”, which, on the principle of the thing, I have opted not to do. So, with those pieces of mild humor out of the way, on to the question at hand.
Multicellularity is challenging. Life is challenging; to say that all there is to unicellularity is self-regulation and reproduction is a gross understatement. But in unicellular organisms you only need to regulate single cells, or loose communities of cells. Once you start organizing multiple cells, you need them to function efficiently, as a team. This teamwork can be summarized with five essential features (Aktipis et al., 2017):
Controlled Cell Death
Division of Labor
Resource Allocation and Transport
Extracellular Environment Maintenance
The first two features are especially important when we consider what happens when the mechanisms controlling reproduction and death of cells are altered or disrupted. The end of multicellular harmony, of having a single cell, or, unchecked, a cell line, going rogue is a disaster. One cell going on it's own, growing, reproducing, and spreading, without coordination: Cancer.
Cancer is an intrinsic problem of multicellularity. Action must be taken to check for genetic damage that could result in unchecked, destructive growth. Countless mechanisms rise up to check for damage, flag damaged cells, and allow a multicellular organism to destroy rampant growths. And these in turn evolutionarily become preoncogenes, new ways for genetic replication to go awry and lead to the death of the organism as a whole to feed the incipient growth.
This problem escalates as the number of cells, corresponding to the number of rounds of cell reproduction, increase, if the rate of oncogenic mutations is the same between organisms. Thus, organisms with longer life-spans (necessitating higher number of replacements of cells to accommodate turnover) and larger body masses would be more vulnerable to cancer over their lifespan (Peto, 1977, 2015).
However, there seems to be a number of notable exceptions to this “rule” when we begin to examine cancer rates in organisms that fall into these archetypes. When examining large animals, there are two major groups that come up: Proboscideans and Cetaceans. Both groups also have rather long lifespans and large body mass, yet have, based on zoo autopsies and other analyses, below average cancer rates compared to other mammals. Recent studies have shown that in these organisms, as well as many others, there are atypically high numbers of various genes involved mediating cell-growth and regulating controlled cell death. In elephants and their kin, the gene TP53 (and more frequently referred to certain circles as p53) exists in over a dozen copies plus numerous retrogenes (Abegglen et al., 2015; Perez and Komiya, 2016; Sulak et al., 2016). p53 is involved in controlled cell-death mechanisms in response to DNA damage, and can be involved in halting the cell cycle (Lowe et al., 1993; Heinrichs and Deppert, 2003). Conceptually, what this means is that when there is a mutation of one of these pre-oncogenes, having an abundance of built in redundant backups will keep uncontrolled cell replication in check. It remains unclear how levels of p53 expression are modulated in elephants to allow for regular multicellular function in spite of having multiple copies of genes that can constrain the cell cycle, or what other genes may be playing a major role in this seeming evolution of cancer resistance.
Proboscidean genetics from both extant and extinct species have been characterized, allowing us insight into the biogeography and timing of speciation over the past several million years. What proves interesting is studies which show that there are in fact three species of extant elephants; two elephants in the genus Loxodonta (what historically were described together as African Elephants), and one in Elephas (Asian Elephants). The former contains two cryptospecies of African elephants, L. africana and L. cyclotis, the savanna/bush and forest elephants; the latter contains the Asian elephant. Recent genetic and morphological evidence indicates that africana and cyclotis are in fact distinct species (more classically cyclotis was considered a subspecies of africana). This becomes far more fascinating when we learn that in a genetic study of both Loxodonta, Elephas, Mammuthus (Wooly Mammoths), and Mammut (Mastodons) Rohland et al. (2010) found the two species of Loxodonta are as divergent from one another as Elephas is from Mammuthus, with a speciation time of at least 2.5 mya. Further studies have shown the number of p53 duplications varies between elephantids, with L. africana having 20 copies (plus retrogenes), Elephas having ~12-17, mammoths having a similar range, and then only 3-8 in the mastodon genome. It would seem that the surge in numbers of p53 genes is relatively recent in Proboscidean evolution, which raises the question: If p53 copies are crucial for cancer mitigation in large Proboscideans, at what point did these series of duplications occur in their evolutionary history?
A number of explanations present themselves. The relatively low number of copies in the mastodon genome could suggest that either the mechanism developed relatively late in the evolution of the large body size, or that other undetermined gene factors have, or had, played roles in reduction of cancer rates in large Proboscideans in conjunction with or in place of these p53 copies. By examining genomic information from both extant (including the seemingly unexamined L. cyclotis) and additional extinct elephant species, as well as increasing the span of the outgroups to other more basal groups (both extant and extinct), one might expect to begin to trace the development of p53 duplicates, as well as transitions in other oncogenic factors. These studies could then be integrated with current human cancer research, examining ways in which synergistic oncomutations interact with p53 to cause tumorigenesis or development of gene therapies to reduce cancer incidence.