Where Did The Platypus Come From?

Have you ever wondered what makes the platypus so weird? Think about it: what kind of evolutionary pressures could have led to an egg-laying, toothless, webbed-footed mammal with 10 sex chromosomes? A group of researchers at Copenhagen University tried to tackle this exact question by mapping the entire platypus genome in a fashion similar to the thirteen-year Human Genome Project in the 1990's [1]. However, before we delve into the detailed genetics of this fascinating creature, we should take a look at its interesting history and investigate why the platypus is categorized as a mammal in the first place.

When people in England first heard news of the platypus, many were skeptical that such an animal existed "perhaps a taxidermy construction of a duck's bill attached to the body of a mole." [2] Once the species was recognized and named, scientists faced the immense challenge of classifying such a unique species. Although platypuses lay eggs and possess characteristics similar to avian or reptile species, namely their bill and webbed feet, their ability to nurse their young classified them as mammals, specifically in a category called Monotreme mammals [3]. While this classification is supported by other platypus characteristics, such as fur, ability to self-regulate temperature, and lungs, it brings into question the subjectivity of living classification systems. Do our methods of classifying animals adequately account for the diversity of life? It is worth exploring the environmental pressures that lead to the evolution of a species so outside our understanding of animals.

Since platypuses contain characteristics of multiple classifications, the Copenhagen researchers viewed their genetic makeup as a link between different taxonomic groups and investigated what evolutionary changes took place that separated certain groups from others. For example, non-monotreme mammals, such as humans, lost the ability to produce eggs sometime in our ancestry; this is because we lost functionality of the three vitellogenin genes required for yolk production. Instead, we possess casein genes, which allow us to produce milk for and nurse our young. Platypuses carry one of the vitellogenin genes present in other egg-laying species, as well as a few of the casein genes, hence their duality in laying eggs while also nursing their young [4]. Traits like this and many others were mapped by the Copenhagen researchers and provide valuable insight into long-term speciation events.

So, a platypus is a mammal, at least according to the (arguably) arbitrary guidelines of modern taxonomy. But the platypus is not only important because it reveals the limitations of our classification systems; its position outside scientific understanding of speciation events helps us draw more complete and nuanced phylogenetic trees, or diagrams of ancestry. Using the genetic makeup of such a mismatched organism, we find new connections between different species and their relations to one another, providing insight into our own ancestry as mammals. 

References

[1] The Human Genome Project. (n.d.). Genome.Gov. Retrieved March 6, 2021, from https://www.genome.gov/human-genome-project 

[2] The platypus puzzle. (n.d.). Retrieved March 6, 2021, from https://www.nhm.ac.uk/discover/the-platypus-puzzle.html 

[3] Is a Platypus a Mammal? (n.d.). WorldAtlas. Retrieved March 6, 2021, from https://www.worldatlas.com/articles/is-a-platypus-a-mammal.html 

[4] Mapping the platypus genome: How Earth’s oddest mammal got to be so bizarre -- ScienceDaily. (n.d.). Retrieved March 6, 2021, from https://www.sciencedaily.com/releases/2021/01/210106133034.htm

[5] Image Cite: https://static.wikia.nocookie.net/phineasandferb/images/6/66/Profile_-_Perry_the_Platypus.PNG/revision/latest?cb=20200401182751

Skulking Spirits and Wicked Witches: The Science and Culture of Sleep Paralysis

It’s the middle of the night when your eyes suddenly burst open. Attempting to shift onto your side, you find that your body is unresponsive. A tingling numbness spreads quickly through your limbs, and you feel a pressure on your chest. Even your fingers refuse to respond. Out of the corner of your eye, you think you notice a shadow entering your room; but, paralyzed, you are unable to cry out or protect yourself.

This terrifying experience depicts a typical episode of sleep paralysis, a common sleep disorder characterized by an inability to move voluntarily while falling asleep or waking up [1]. Although head, limb, and body movements are impaired during sleep paralysis, the sleeper still has full control over her eyes and breathing [2]. This often occurs as one is entering or exiting REM sleep, a stage in which the sleeper’s muscles are paralyzed in order to prevent dangerous movement during dreams [3]. Therefore, factors that disrupt the sleep cycle (such as existing sleep difficulties, alcohol consumption, anxiety, depression, and trauma increase the chances of experiencing an episode of sleep paralysis [1].

In most cases, physical paralysis is accompanied by hallucinations, a state between dream and wakefulness often referred to as the “Nightmare” episode [4]. Although specific visions will vary based on the sleeper, there is a common theme of an intruder, such as a strange person, demon, or old hag, lurking in the bedroom or sitting on the sleeper’s chest [2]. For many cultures, these hallucinations are linked to a deeper significance: for example, 92 out of 100,000 healthy Laotian Hmong men have died from Sudden Unexplained Nocturnal Death Syndrome (SUNDS). The reason? Members of the Hmong community who are traditionally animist believe that sleep paralysis occurs when a dab tsog (nightmare spirit) sits on the sleeper’s chest and steals her breath. The prevalence of this belief causes significant psychological stress which, coupled with the sleep paralysis episodes themselves, is hypothesized to be a trigger of SUNDS among the Hmong people [5]. Furthermore, many Italians attribute episodes of sleep paralysis to an attack of the Pandafeche, which is described as an evil witch, ghost, or cat-like creature. To prevent sleep paralysis, it is recommended to place a broom upside-down by the bedroom door, since the Pandafeche will get stuck counting the fibers of the broom instead of attacking the sleeper [6].

The cultural significance behind sleep paralysis not only defines the disorder’s prevalence, but is shown to actually intensify its effects on the sleeper. Upon comparing sleep paralysis within Italy and Denmark (a country without widespread folklore associated with the disorder), researchers discovered that Italians reported higher rates of sleep paralysis, more prolonged physical effects, and a greater fear of the disorder–42% of Italian sleep paralysis sufferers revealed that they feared dying during an episode, as compared to 17% of Danes fearing the same fate [6]. As stated in the study of Hmong sleep paralysis victims, “culture specific stressful experiences [are] significantly associated with...REM-related disorders, suggesting a bio-psychological connection” [5]. For this reason, different cultures’ interpretations of sleep paralysis likely affect the role it will play in the citizens’ lives and its psychological repercussions. 

Sleep paralysis is a prevalent global phenomenon–it is estimated to affect between 1.7% and 40% of the general population, and 28% of college students [2]. This significant percentage suggests yet another reason for students to prioritize a healthy sleep schedule. And perhaps it wouldn’t hurt to keep an upside-down broom inside your doorway...just in case.

References

[1] Denis, D.; French, C.C.; Rowe, R.; et al. A twin and molecular genetics study of sleep paralysis and associated factors. J Sleep Res. 2015, 24 (4), 438-446.

[2] Olunu, E.; Kimo, R.; Onigbinde, E.Q.; et al. Sleep Paralysis, a Medical Condition with a Diverse Cultural Interpretation. Int J App Basic Med Res. 2018, 8 (3), 137-142. 

[3] Davis, S. Sleep Paralysis: Demon in the Bedroom. WebMD. 2001. 

[4] Cox, A.M. Sleep paralysis and folklore. J Roy Soc Med. 2015, 6 (7).

[5] Young, E.; Xiong, S.; Finn, L.; et al. Unique sleep disorders profile of a population-based sample of 74 Hmong immigrants in Wisconsin. Soc Sci Med. 1982, 79, 57-65.

[6] Jalal, B.; Romanelli, A.; Hinton, D.E. Sleep paralysis in Italy: Frequency, hallucinatory experiences, and other features. Transcult Psychiatry. 2020.

[7] Image source: https://inews.co.uk/inews-lifestyle/sleep-paralysis-night-terrors-211699 

Alkaline Water: Just a Fad or For Real?

Alkaline water is becoming increasingly popular because of its supposed health benefits, which include detoxifying the body [1], improving athletic performance [1,2], and treating cancer [3]. It is produced through water electrolysis, which involves using an electric current to split water into oxygen and hydrogen gas [4]. This is followed by a transfer of hydroxide ions, which results in acidic and alkaline water which can be individually collected [4]. Although proponents of alkaline water swear by its benefits, the reality is that the science is not as conclusive about what it has to offer. 

Some research suggests that alkaline water may indeed have benefits. For example, in a study looking at the effects of alkaline water on rats, a team of researchers led by Toshiki Yoneda found that rats that were given a high-fat diet and alkaline water gained less weight and showed less alveolar bone loss than rats who were only given a high-fat diet [5]. Researchers have also looked at the effects of alkaline water in humans. In a study looking at men and women with metabolic syndrome, another team of researchers led by Tyler LeBaron found that participants who took an alkaline water supplement for 24 weeks showed reduced blood cholesterol and glucose levels, as well as improved inflammation markers compared to participants who received a placebo [6]. In another study looking at the effects of alkaline water on exercise, a team of researchers led by Toshio Mikami found that participants who drank alkaline water before exercising reported less tiredness and exhibited greater endurance than those who drank placebo water [2].

Although the benefits of alkaline water may be compelling, other research provides evidence to refute them. For example, in another study looking at the effects of alkaline water on exercise in athletes, a group of researchers led by Cheong Ooi found that participants who drank alkaline water before exercising did not show improvements in exercise performance or self-reported tiredness compared to those who drank placebo water [7]. In a systematic review of the literature surrounding alkaline diets and water, Fenton and Huang found no studies looking at alkaline water and cancer in humans and concluded that the use of alkaline water to treat cancer is not supported [3]. Finally, some research suggests that alkaline water may even be harmful. For instance, in a study looking at the effects of long-term exposure to alkaline water in rats, a team of researchers led by Marina Merne found that rats who were given alkaline water for 52 weeks showed inhibited growth, having lower body weights than control rats despite having the same food and water intake [8]. In another study also looking at rats, Watanabe and Kishikawa found that rats who were given alkaline water showed degradation of heart muscle myosin and a decrease in creatine kinase activity, both of which may lead to heart muscle scarring and death [9]. From the sparse and conflicting research, alkaline water may continue to be a fad until larger human studies are conducted.

References

[1] Kurzweil, R.; Grossman, T. Fantastic Voyage: Live Long Enough to Live Forever; Rodale, 2004.

[2] Mikami, T.; Tano, K.; Lee, H.; Lee, H.; Park, J.; Ohta, F.; LeBaron, T. W.; Ohta, S. Drinking Hydrogen Water Enhances Endurance and Relieves Psychometric Fatigue: A Randomized, Double-Blind, Placebo-Controlled Study1. Can. J. Physiol. Pharmacol. 2019. https://doi.org/10.1139/cjpp-2019-0059.

[3] Fenton, T. R.; Huang, T. Systematic Review of the Association between Dietary Acid Load, Alkaline Water and Cancer. BMJ Open 2016, 6 (6), e010438. https://doi.org/10.1136/bmjopen-2015-010438.

[4] Henry, M.; Chambron, J. Physico-Chemical, Biological and Therapeutic Characteristics of Electrolyzed Reduced Alkaline Water (ERAW). Water 2013, 5 (4), 2094–2115. https://doi.org/10.3390/w5042094.

[5] Yoneda, T.; Tomofuji, T.; Kunitomo, M.; Ekuni, D.; Irie, K.; Azuma, T.; Machida, T.; Miyai, H.; Fujimori, K.; Morita, M. Preventive Effects of Drinking Hydrogen-Rich Water on Gingival Oxidative Stress and Alveolar Bone Resorption in Rats Fed a High-Fat Diet. Nutrients 2017, 9 (1). https://doi.org/10.3390/nu9010064.

[6] LeBaron, T. W.; Singh, R. B.; Fatima, G.; Kartikey, K.; Sharma, J. P.; Ostojic, S. M.; Gvozdjakova, A.; Kura, B.; Noda, M.; Mojto, V.; Niaz, M. A.; Slezak, J. The Effects of 24-Week, High-Concentration Hydrogen-Rich Water on Body Composition, Blood Lipid Profiles and Inflammation Biomarkers in Men and Women with Metabolic Syndrome: A Randomized Controlled Trial. Diabetes Metab. Syndr. Obes. Targets Ther. 2020, 13, 889–896. https://doi.org/10.2147/DMSO.S240122.

[7] Ooi, C. H.; Ng, S. K.; Omar, E. A. Acute Ingestion of Hydrogen-Rich Water Does Not Improve Incremental Treadmill Running Performance in Endurance-Trained Athletes. Appl. Physiol. Nutr. Metab. 2019. https://doi.org/10.1139/apnm-2019-0553.

[8] Merne, M. E.; Syrjänen, K. J.; Syrjänen, S. M. Systemic and Local Effects of Long-Term Exposure to Alkaline Drinking Water in Rats. Int. J. Exp. Pathol. 2001, 82 (4), 213–219. https://doi.org/10.1111/j.1365-2613.2001.iep0082-0213-x.

[9] Watanabe, T.; Kishikawa, Y. Degradation of Myocardiac Myosin and Creatine Kinase in Rats Given Alkaline Ionized Water. J. Vet. Med. Sci. 1998, 60 (2), 245–250. https://doi.org/10.1292/jvms.60.245.

[10] Unsplash. Photo by quokkabottles on Unsplash https://unsplash.com/photos/6wn80vdAHWc (accessed Feb 11, 2021).

A Million Dollar Question

Math seems like such a well-defined subject that it is difficult to believe that there are still any big questions left unanswered. After all, for a subject that’s been studied extensively for at least 3000 years and one that builds on itself so easily, how can there be anything left unknown? However the reality is there are so many unproven conjectures and areas of research that it would be impossible for me to list them all. 

At the turn of the millennium, the Clay Mathematics Institute chose 7 hugely important unanswered problems still plaguing mathematics today. Whoever solves one of the “Millenium Problems” is entitled to receive a whopping $1,000,000 for their work. 

So what kinds of solutions are worth a million dollars?  The following is the statement of the Poincaré Conjecture, the only Millenium Prize Problem to have been solved so far:

“Every simply connected, closed 3-manifold is homeomorphic to the 3-sphere” [1].

So, let’s break down exactly what this statement is saying. First, what is a 3-manifold? In mathematics, a manifold is essentially a surface with the property that at any given point, the surface resembles our regular intuition of a space with some number of dimensions [2]. We actually see a manifold in action every day by living on the Earth. Although the Earth is a sphere, when we walk on it, it’s easy to believe we lie on a flat 2-dimensional surface. Thus, the earth, and any 3-dimensional sphere, is a 2-manifold since when we walk on it, we effectively walk in a 2-dimensional space. 

More generally, a n-manifold is a higher dimensional (for simplicity's sake we can just assume the dimension is n+1) surface, but when an observer zooms in on a particular point on the manifold, the observer will see that an n-manifold will behave like n-dimensional Euclidean space. Thus, the 3-manifold is a 4-dimensional surface that behaves in 3-dimensions when we zero in on it.

A 3-sphere is a specific example of a 3-manifold, but what exactly is it? To understand what a 3-sphere is, it is useful to examine a 2-sphere. To begin, a 2-sphere is what we normally think of when we see the word “sphere”: a 3-dimensional surface with each point equidistant from a given center. Likewise, a 3-sphere is just the 4-dimensional analog; it is a 4-dimensional surface with each point equidistant from a given center. 

The conjecture proposes that any 3-manifold that is continuous (without any holes or other weird features) can be molded in a way that transforms the 3-manifold into the 3-sphere. For a slightly more rigorous definition, each point on a 3-manifold can be mapped to a unique point on the 3-sphere and vice-versa. 

Though we had to go through some complex definitions to understand the conjecture, the statement itself is simple enough and seems rather intuitive. However, it was actually proposed by Henry Poincaré in 1904, before being solved over one hundred years later by Grigori Perelman [3]. That’s not to say no one else had attempted to solve the question. By some metrics, the Poincaré Conjecture has had more false proofs than any other statement in recent history [3]. Rather, the fact that it took over a century to solve it shows how difficult proving this seemingly-simple statement is and there are six more just like it! 

There are still a lot of unanswered questions in mathematics, but with each solution, we get closer to a better understanding of the universe we live in.

References

1. [Image] Veisdal, J. The Poincaré conjecture - cantor’s paradise - medium https://medium.com/cantors-paradise/the-poincar%C3%A9-conjecture-cb4ca7014cc5 (accessed Mar 1, 2021).

2. http://www.owlnet.rice.edu/~fjones/chap1.pdf (accessed Mar 1, 2021).

3. Prize, P. The Hundred-Year Quest to Solve One of Math’s Greatest Puzzles by George G. Szpiro.

4. Poincaré Conjecture https://www.claymath.org/millennium-problems/poincar%C3%A9-conjecture (accessed Mar 1, 2021).

Unspoken Burdens: The Psychology of Secrets

You have just finished taking an incredibly lengthy exam. As you head to your locker, your friend runs up to you and reveals that she cheated on the exam. You promise not to tell anyone about it, but it takes all of your effort to not expose your friend the next time you talk to your professor. Keeping a secret is an intensive act that involves a complex set of physical, mental, and social processes. Psychologists have asked questions about these processes, and their research has given us some insight into the secrets of secrecy.

How do secrets affect us?

Keeping secrets may be detrimental to one’s health, as secrecy is correlated with negative consequences for both physical and mental well-being [1]. For instance, in a study looking at gay men, Cole et al. found that there was an association between keeping sexual identities secret and physical conditions such as cancers and infectious diseases [2]. How preoccupied people feel with the secret can potentially influence its consequences. In a series of four studies where participants made judgments of hill slant, which are linked to physical burden, Slepian et al. found that participants’ preoccupation with secrets they were keeping predicted their judgments of hill slant [1]. Emotions surrounding the secret can also affect the people keeping it. In a study asking participants to recall secrets they were keeping, Slepian et al. found that while feeling shame about the secret led to more mind wandering towards the secret, feeling guilt about the secret led to less of this mind wandering [3]. These studies show that, in order to fully understand the consequences of secrecy, we need to consider factors beyond the mere act of keeping a secret.

What is the role of secrets in our lives?

Even though secrets can have negative consequences for their keepers, they can also serve important social functions. Sharing secrets may have a multitude of purposes like expressing strong emotions, creating and increasing intimacy with others, and seeking and establishing a mutual understanding with others [4]. Secrets may also be related to people’s social networks. For example, social networks can shape secrets. Aspects of a person’s social network, like the closeness of its members, can affect whether sharing secrets is used to support or harm others [4]. Secrets can also shape people’s social networks, as people’s responses to secret-sharing can lead to stronger relationships if the response is positive or weaker relationships if the response is negative [4]. Even children seem to understand the social importance of secrets: in a series of studies where children were tasked with making judgments of friendship based on the sharing of secrets versus material resources or other types of information, Liberman and Shaw found that the children tended to view secret-sharing as an important indication of friendship compared to the other kinds of sharing [5]. Ultimately, despite secrecy being difficult and its association to negative health consequences, secrets are still an integral part of our social lives.

References

[1] Slepian, M. L.; Camp, N. P.; Masicampo, E. J. Exploring the Secrecy Burden: Secrets, Preoccupation, and Perceptual Judgments. J. Exp. Psychol. Gen. 2015, 144 (2), e31–e42. https://doi.org/10.1037/xge0000052.

[2] Cole, S. W.; Kemeny, M. E.; Taylor, S. E.; Visscher, B. R. Elevated Physical Health Risk among Gay Men Who Conceal Their Homosexual Identity. Health Psychol. 1996, 15 (4), 243–251. https://doi.org/10.1037/0278-6133.15.4.243.

[3] Slepian, M. L.; Kirby, J. N.; Kalokerinos, E. K. Shame, Guilt, and Secrets on the Mind. Emotion 2020, 20 (2), 323–328. https://doi.org/10.1037/emo0000542.

[4] Cowan, S. K. Secrets and Social Networks. Curr. Opin. Psychol. 2020, 31, 99–104. https://doi.org/10.1016/j.copsyc.2019.07.038.

[5] Liberman, Z.; Shaw, A. Secret to Friendship: Children Make Inferences about Friendship Based on Secret Sharing. Dev. Psychol. 2018, 54 (11), 2139–2151. https://doi.org/10.1037/dev0000603.

[6] Unsplash. Photo by Gama. Films on Unsplash. https://unsplash.com/photos/hpv81oxYZ34 (accessed Dec 7, 2020).