Entrapta: Another Mad Scientist

By Drew Anderson (@AndersonEvolve)

Entrapta_Character_Profile

I’m a sucker for remade cartoon series from my childhood.  I sat through the originals made in the 1980s and they are just not good; seriously, keep your nostalgia intact and don’t rewatch your childhood favorites (video games hold up though).  After rewatching all nine seasons of the original Teenage Mutant Ninja Turtles (TMNT) cartoons, I realized only 2 seasons could be considered good.  Cartoons today are just better written and better animated. I’ve enjoyed Disney’s remake of Ducktales (David Tennant!!), Nickelodeon’s remake of TMNT (also David Tennant for a season), Netflix’s remake of Voltron, and even though it didn’t get a good run, Cartoon Network’s remake of Thundercats.  I’m also happy to introduce these shows to my daughter (she’s almost got the theme song down to Ducktales). Whoo hoo!  

The show I’m going to discuss today is one of my daughter’s favorites and one I’ve made it through all 13 episodes about six times now (twice in spanish!)She-Ra.  This is not a full on review of the show and I have so many thoughts on it (e.g., I find Scorpia more sympathetic than Catra and for all the body positivity, it still falls into the high fantasy depictions of good = beautiful and bad = monstrous).  Instead I want to point out it hits a trope that is quite common in stories with a scientist component: the mad/driven scientist who ignores morality in favor of their discoveries or “progress.” In this case that niche is filled by an admittedly fun and quirky character, Entrapta.

SPOILER ALERT

Our first introduction to Entrapta has her working on First Ones’ tech, causing robots in her kingdom to go crazy and terrorize her people.  She doesn’t care about the harm, only the way the robots react. She only helps Adora and Glimmer because they insist and she’s curious about solving the problem.  When we see her again, the group is invading the Fright Zone and she repeatedly wanders off to investigate something she thought interesting without a care as to why they are there, which was to save Glimmer.  She ends up separated and sneaks around while fiddling with tech; eventually joining Catra so she can “tinker.” Her final experiment literally destabilizes the world and she is fascinated. If any player in a D&D campaign asks to be Chaotic Neutral, I would have them watch her so they would understand how bad an idea that is.  She doesn’t mean harm, she only is only interested in learning things, regardless of the outcome.

SPOILERS END HERE

Media loves to paint scientists as uncaring or willing to ignore what is right for the sake of their discoveries.  Sometimes their motivations are good (The Lizard, Dr. Octopus, Dr. MalusJessica Jones), others just want progress (Dr. Frankenstein, Dr. WuJurassic Park), others have gone insane (Drs. Isley, Quinzel, and DoomPoison Ivy, Harley Quinn, and Dr. Doom respectively).  Even good scientists are often portrayed as eccentric (Dr. MalcolmJurassic Park, Dr. Okun and David Levinson—Independence Day), aloof (Dr. Strange), or careless with their work (Iron Man, Dr. Banner, Dr. BrundleThe Fly).

Society seems to view scientists as apart from society rather than part of society.  What’s interesting about that is that in science ethics class we, as scientists, are asked to keep tabs on our thoughts and opinions while not letting them interfere as we work on our results.  In general, we’re asked to only provide results and advice as well as to identify potential sources of bias and conflict. Many of us though do care a lot about society and those around us, so some feel the need to speak up and participate.  Applied scientists, those that work on things with direct benefits to the public, are especially important in this respect, as their discoveries and how they’re used directly affect society. Basic scientists, those that determine how the world works, without directly trying to affect society, are also important, but their work is farther removed from direct application.  Even still, we are hardly uncaring or willing to cause harm (even unintentionally).

That’s not to say scientists haven’t been involved in some horrible things.  Most recently we have had the CRISPR-modified babies, there was that whole period of eugenics (which isn’t gone considering the debate on using CRISPR on embryos), and the racist/sexist history of human experimentation.  We can also notice the list I provided above isn’t diverse and the two female examples I’ve come up with aren’t treated kindly in their depictions, but this is about personality tropes, as Entrapta works independently of whatever physical representation she’s given.

While we do see some good scientists (Peter Parker, Dr. Wattney—The Martian, and Shuri—Black Panther), Hollywood still could do a better job of realizing that scientists are people with the same strengths and failings as anyone else.  We are diverse in our personalities and mannerisms, despite common perception we’re not all INTJ on Briggs-Meyer (which is bunk test by the way).  We even have different aspirations; for example, I would like to learn some things about sexual selection and contribute to the knowledge base while teaching others, but I don’t have grand aspirations of transforming the field (though if I made a discovery that did, I would certainly be excited).  So perhaps, some writers would be better thinking of character traits and motivations before assigning them “scientist”, as it might just make for a more compelling and different story.

Got thoughts/feedback?  Can you think of any pop culture scientists that aren’t eccentric/oblivious/unintentionally harmful (i.e., a “normal”-ish personwe’re all different)?

 

Hit us up @SciQuests  

Family Life in Graduate School

Drew Anderson  (@AndersonEvolve)

I have recently seen many great takes on Twitter about the need to balance personal life and student life and how schools don’t always foster that kind of mindset.  Yes, being in graduate school makes it hard to keep yourself happy and keep your married/cohabitating/romantic life happy, but one thing that isn’t discussed is the challenges that arise from having a family of your own.  Full disclaimer, I have a family and am fortunate enough to have the support structure necessary to keep on track and be there for my daughter. Most of what I point out has been fairly easy for me to address, but I cannot imagine the trials someone endures in grad school who does not have family support or is a single parent.  

While most principal investigators (PIs) are supportive of graduate students and postdocs who are already parents or expecting to become parent, the general advice I’ve come across for grad students is to not have children in graduate school or delay until you are writing.  While, given the way graduate school works, this advice makes practical sense; that doesn’t make it right. I know people who want children earlier in their lives so they can have their nest empty sooner and/or be healthier and more active to keep up with their children. My decision was based on time, my wife and I have passed the point where each year of life now puts a pregnancy at more risk and we didn’t want to keep waiting.  It is also possible that someone didn’t intend pregnancy, but made a personal choice to keep their child. Whatever the reason, asking someone to change their reproduction to fit graduate school rather than the other way around is unacceptable.

My daughter didn’t arrive until the last of my benchwork was completed, but I have continued on with analysis and writing.  The idea that writing is somehow not hampered by childcare is laughable. I think I would be able to manage benchwork better than writing, as writing takes more mental effort and takes some time to get productive (I need a least a 2 hour block to get some quality writing in).  This type of stuff though is typical of any job and any stage of your career; getting things done while parenting is the gig and people have been doing it a long time.

Where graduate school often fails compared to other jobs is time and money.  My PI was kind enough to allow me flexible hours, so I could split care with my wife and mother-in-law, and I had a team-taught lab where I front-loaded the work in anticipation of her birth and my co-teaching assistant took on the brunt of work on the back end.  As you can see I had two people to split time of care with and was able to have my job work with me as well. I don’t think many graduate students would have this luxury. With the wrong PI, such as one who demands 60+ hours of work and must come in on weekends, a new parent would be quickly overrun and extremely stressed.  Also worth noting, I was able to teach/work right up until the week she was born and was back around the lab the week after–something a female student who actually is pregnant may not be able to do.

So how do graduate programs work with students bringing in a family?  One school I looked at offered 6 months paid parental leave and pushed back your graduation date 6 months, with no penalty for the delay, but I haven’t heard of many programs offering this kind of deal.  While I don’t regret my academic decision of my current program, that deal would have been great for me. Finding a groove between childcare and work takes time and those first few months are challenging, so knowing that your graduation and pay won’t be affected as you figure it out is important.  

Childcare is also really important and something schools don’t offer help on.  Both my wife and I work, but can balance our schedules to makes sure we’re home or a family member can watch our daughter.  The alternative is childcare centers, which have long wait times and can be expensive. Here in Texas, the childcare situation isn’t great as the cheaper care centers are often unlicensed.  My university offers a childcare center (with a wait list), but even with the student discount it would cost ~40% of my take-home income. In addition, the center only offers 5 day care, meaning I can’t reduce the cost by only having them watch her for only 2 or 3 days.

By now you’ve probably realized that issues with childcare in graduate school are the same as childcare for lower-income families because that is what most graduate students are.  By having a wonderful partner (my wife), some extra hands, and a family support structure should I need it, I have avoided many of these problems. I believe though that institutions of higher learning should not exclude people (albeit unintentionally from demanding hours and lack of childcare options) simply because they have a family.  They should work to alleviate some of the stress that having children puts on parents so students can earn their diplomas and hopefully elevate their family and contribute to science.

I know there are likely more issues that haven’t crossed my mind.  There is a whole other discussion on social impacts and expectations based on gender that I didn’t even wade into.  If you would like to share your thoughts, please hit us up on Twitter!

@SciQuests  

Caloric Requirements of Superheroes

By Scott Mattison (@FoolsPizza)

The average person burns around 2000 calories a day. This approximation is found on pretty much every food wrapper when they provide your “estimated daily values”. Superheroes aren’t average people and likely need an above average caloric intake. Below are some very basic approximations to determine the number of Calories a superhero burns when using their power for 1 minute

calories
Number of Calories burned per minute by various superheroes.

If you are still reading, you are probably curious how I came up with these values. So let’s go through them based on their powers. First of all I should probably define what a Calorie is. Calories are a unit measure of energy and Calories as reported on food are actually 1000 calories (with a lower case “c”). 1 calorie is the energy required to raise the temperature of 1 gram of water 1 degree Celsius.

Flash & Dash

Both Flash and Dash’s caloric requirements are based on estimated VO2 maximum converted to Calories. VO2 max is the measurement of the maximum possible oxygen that may be utilized during exercise. I estimated VO2 max using ACMS running VO2 equation which provides a very rough approximation based on body weight, speed, and incline.  So to calculate VO2 max, I needed to first find the top speed of Flash and Dash.

The Flash’s top speed varies wildly in the comic books, sometimes being shown as capable of running faster than the speed of light other times he has a maximum speed around Mach 3 (three times the speed of sound, or 1029 m/s).

Dash is a bit harder to estimate as there is much less data to work from, but I based my estimation on the scene in “The Incredibles” where Dash gets caught on camera placing a tack on the teacher’s chair. The camera which is likely updating between 24 and 30 frames per second and Dash traverses the distance from the back of the room to the teachers desk and back (roughly 30 feet) within one camera frame so I estimate Dash’s top speed to be 220 m/s. This is reasonable as we never see Dash break the sound barrier in either Incredibles movie.

Wolverine

Wolverine was probably the hardest to estimate and is most likely the most incorrect of all of my approximations; however, if anything, this estimate is low. Wolverine’s primary power is a healing factor that allows him to recover from almost any injury. The speed at rate his healing factor works is a little bit of a debate, so I have to make some assumptions. I settled on the assumption that Wolverine can heal a broken bone in a minute. (This is obviously a little silly since his bones are practically unbreakable due to the Adamantium bonded to them).

The energy expended by the body due to injury is also difficult to estimate, but many sources recommend an increased intake of 400-500 Calories per day while healing from a broken bone and it takes 6 – 8 weeks for the body to repair a minor fracture. Thus it takes ~16800 Calories for the body to repair a broken bone.

Batman

Batman may not have any super powers (except maybe always having a plan somehow), but he is trained in several forms of hand to hand combat. A quick search estimates that a high intensity martial arts session may burn up to 960 Calories in 30 minutes.

Jean Grey

Jean Grey’s powers of telepathy allow her to lift objects with her mind. Lifting any object requires energy in the form of weight of the object multiplied by the height the object is lifted. When not The Phoenix, Jean Grey has demonstrated the ability to lift objects up to nearly 50 tons. Assuming she lifts this weight at a rate of 10 meters per minute (possibly a low estimate) this would required 1063 Calories of energy.

Bonus: Scott Summers aka Cyclops

This blog post was originally conceived around the idea that Cyclops’ optic blasts would require an insane amount of energy to sustain. However, during my initial research I learned that Cyclops is not actually emitting lasers from his eyes, but is instead opening an aperture to another dimension and allowing energy from that dimension to enter ours. So yeah, you learn something new every day. However, going with my original idea, what would happen if someone like Cyclops existed that could actually emit lasers from their eyes (like Superman, but not solar powered).

Cyclops’ optic blasts emit 2 Gigawatts of energy (2 * 109 Joules/second). There are 4184 Joules in a Calorie, which means that in one minute, our Cyclops equivalent would burn 28680688 Calories

Do Professor Xavier and Magneto Have the Same Base Power?

By Scott Mattison (@FoolsPizza)

Before we dive into this, I must first admit that I am not an avid reader of the X-men comics; however, I have really enjoyed a lot of the X-men movies, specifically X-men: First Class. Throughout the X-men series, Charles Xavier and Eric Leschner have often been depicted as two sides of the same coin, both working to further the cause of mutants. Xavier believing that advancing the mutants’ cause must be done (mostly) through working with humans and finding common ground; whereas Magneto believes that mutants and humans are destined to be enemies that mutant rights can only be ensured through force. I am sure there are many others out that could have a much more thorough discussion regarding the symbolism and underlying messages that are rooted the relationship between these two characters; however, I am here to pose a much more important theory. Magneto and Professor Xavier share the same base ability: the manipulation of magnetic fields.

Xavmags
Magneto and Charles Xavier discussing their world views. All Marvel characters and the distinctive likeness(es) thereof are Trademarks & Copyright © 1941–2018 Marvel Characters, Inc. ALL RIGHTS RESERVED.

I am not going to waste time arguing that the manipulation of magnetic fields is Magneto’s power, it is literally in his name! Now for the harder one, Charles Xavier.

In the X-men comics Professor Xavier is depicted have the ability to both read the minds of others as well as implant thoughts into the brains of others through what is known as telepathy. Telepathy is the communication of thoughts and ideas between individuals without the use of the traditional senses. Most of you are thinking Charles Xavier is a known telepath, how you could possibly argue that manipulation of magnetic fields is his power? The answer to this question are two fundamental laws of physics, Ampere’s Law and Faraday’s Law of Induction.

Let’s start with Ampere’s Law. Ampere’s Law defines the generation of magnetic fields due to electricity. Ampere’s Law states that magnetic fields may be generated by the motion of an electrical current or by changing electrical fields.

Our thoughts are complex firings of neurons within the brain, transferring electrical potentials from one brain cell to another. One way scientists study the brain is by tracking these electrical potentials through what is known as electroencephalography (EEG). An alternative to EEG is called magnetoencephalography (MEG) and tracks the small magnetic fields generated when neurons are communicating. This is a practical application of Ampere’s Law. From this, we see two possible ways that Charles Xavier could be telepathically reading the minds of others, either through interpretation of the electric fields (similar to a really fancy EEG) or the interpretation of the magnetic fields (a really fancy MEG). We still do not know how he could possibly place thoughts into the minds of others.

490px-VFPt_Solenoid_correct2.svg
An illustration of the the relationship between electricity and magnetism. The arrows represent the magnetic field generated by the current moving through a wire wound around a center axis. The circles represent the cross section of a wire. Source: Wikipedia

For the answer to this, we go back to physics, our good friend Faraday, and his law of induction. Faraday’s Law of Induction states that any change in the magnetic environment of a coil of wire will cause a voltage to be induced in the coil. This means that by changing a magnetic field, we can actually cause the generation of electricity. If the firing of neurons is just changes in voltage potentials across the neuron cells, this means that a magnetic field could cause a neuron to fire.

In fact, this has been demonstrated in medical science. The FDA actually places limitations for how fast the magnetic field inside of an MRI machine can change to prevent muscle spasms in patients.Additionally, there are new fields treatments for depression and anxiety being developed that use targeted magnetic fields to stimulate regions of the brain. So far, these approaches have been shown to be highly targeted and extremely safe. (Author’s Note: MRI machines are extremely safe and none of the discussed technologies could in anyway control your mind).

Scientists are still working to map the complex neural interactions that occur in the brain. While research has begun to be able to map out emotional responses and regions of the brain linked to various types of thought, we are still a long way from reading someone’s mind. However, despite current limitations of science, by combining the concepts of Faraday’s Law and Ampere’s Law we can see that Professor Xavier could gain the abilities of telepathy from a very precise control and interpretation of remote magnetic fields. Of course there are alternate interpretations, Xavier could easily be manipulating and reading the electrical fields in the brains of others. Perhaps more concerning is that regardless of whether or not Xavier can control magnetic fields, with a little practice Magneto could definitely gain the abilities of telepathy.

Beer Today, Gone Tomorrow

By N. Ace Pugh (@DrAcePugh)

The Intergovernmental Panel on Climate Change (IPCC) recently published their report on the possible consequences of global climate change.  Left unchecked and without necessary corrective steps the world will not avoid its most dire effects.

I highly recommend reading this report, at the very least looking at the policymaker summary. The outlook is grim. Imagine, if you will, a nigh-apocalyptic scenario: sea levels rise, storms intensify, forest fires become both more common and more deadly, coral reefs die off, and tropical diseases such as malaria become much more common. Do you also want a side of widespread famine, wars over water (but see), uninhabitable Middle East with that order? Sure thing. Humanity always aims to please. Wealthy, temperate countries such as the United States will likely be less affected at first, which is incredibly unfair because the U.S. and other first world nations disproportionately contributed to the problem. Nonetheless, the consequences of climate change will affect everyone, and the U.S. is no exception. We should all be extremely concerned.

fig1
It’s going to be a real scorcher. [Source]

The very real doom and gloom of climate change is already widely reported, albeit not to the degree that it perhaps should. Future citizens of the world, should society survive in its current form, will ultimately judge how we respond to this threat. I’m not here to write an entire post extolling the virtue of taking personal steps to reduce your own environmental impact while (much more importantly) calling for you to vote for representatives that will rein in large corporations and act against climate change, although you should certainly do those things. No, I’d rather focus on one solitary consequence of climate change and save that larger discussion for a different time.

Today’s blog post is about an interesting, plant breeding-centric revelation that I’ve stumbled across in my internet meanderings and I believe it is of the utmost importance that I share it with you. Speaking of which, you may want to grab a frothy glass of your favorite craft beer before you read the rest of this post. In fact, get an entire six-pack ready.

Fig2
Drink. It. In. [Source]

Climate change is coming for our beer. Yes, you read that correctly folks. A recent study published in Nature Plants that was conducted by Xie et al. has concluded that beer is likely to skyrocket in price due to growing conditions becoming inhospitable to barley as a consequence of climate change. Beer prices will likely increase drastically, and that is a direct result of the decreased availability of barley. Using a combination of different models, the researchers found that barley yield losses are going to range from 3% to 17% depending on the severity of the actual conditions we experience (i.e., how much we do to address climate change). Beer consumption will go down in many countries and the price increases are likely to be quite high. For example, Xie et al. predicted price increases of almost 200% in Ireland (better stockpile that Guinness).

 

Fig3
Changes in beer consumption and price under increasingly severe drought–heat events. Each column presents the results for the ten most affected countries in the regional aggregation of this study. a–d, Absolute change in the total volume of beer consumed. e–h, Change in beer price per 500 ml. i–l, Change in annual beer consumption per capita. The severity of extreme events increases from top to bottom. The length of the bars for each RCP shows average changes of all modeled extreme events years from 2010 to 2099, which are shown to the left of each bar, and the colors of the bars represent per-capita gross domestic product (see color scale). Whiskers indicate the 25th and 75th percentiles of all changes (n = 17, 77, 80 and 139 extreme events under RCP2.6, RCP4.5, RCP6.0 and RCP8.5, respectively; see percentage changes with full range for all main beer-consuming countries in Supplementary Figs. 26–28; absolute changes in Supplementary Figs. 30–32). (Adapted from Xie et al, 2018)

 

As you can see, the situation becomes worse when conditions are most intense (four different climate scenarios were tested). These findings are sure to sound quite terrifying to any fellow beer connoisseurs, since the beverage is usually loved for its affordability as well as its taste. If beer is as expensive, or more so, than wine and lower end liquor, its popularity will likely wane.

Unfortunately, there are few alternatives to barley. Most of the breweries that you’re familiar with rely on the crop. However, those of you that are on gluten-free diets may already be aware of one alternative that is near and dear to yours truly: sorghum! Yes, sorghum can be used in the brewing of beer, although beer made from sorghum is not very popular in the U.S. Those that have tasted it will note that the flavor is not comparable to most of the more popular beers with which we’re familiar.  While this is purely subjective, I happen to agree that it simply doesn’t have the necessary ‘bite’ that you expect in a good craft beer (I could never be accused of being a shill for “Big Sorghum” when it comes to my beer preferences). That isn’t to say sorghum beer doesn’t have popularity elsewhere, particularly in many African countries.

 

Fig4
Sorghum: The hero that we need, but not the hero that we deserve. Image Credit: N. Ace Pugh (Texas A&M University)

 

Nevertheless, sorghum and sorghum beer will likely need to become more attractive to producers and brewers, respectively, as the possible range for growing barley becomes more and more limited. While the beer it leads to is quite different in taste, sorghum can withstand drought and heat comparatively better. Whether or not the sorghum beer will become more palatable to U.S. consumers in the future is difficult to say. We simply don’t know. No matter how you slice it, a world that is inhospitable to barley is a world inhospitable to beer as most Americans currently know it. If the introduction of this blog post wasn’t enough to concern you, perhaps our impending beer crisis will.

How will we know if we’ve found Martian microbes?

By Reed Stubbendieck (@bactereedia)

curiosity
Figure 1. Curiosity Mars Rover taking a selfie. [Source]
Drew’s recent blog post spurred a conversation between the two of us about the first extraterrestrial life that humans will encounter. In the end, we both agreed that when/if humans discover aliens, they’ll most likely be microbial.

We are not alone in this assertion. At this very moment, the NASA Mars rover Curiosity (Fig. 1) is currently roaming the surface of the red planet using its suite of instruments to detect and characterize organic molecules that could be indicative of life from ancient aqueous environments. Intriguingly, data already collected by Curiosity has indicated that there are environments on Mars that may have once been habitable for microbial life!

Unfortunately, Curiosity is unable to directly detect living microbes, which begs the question: how will we really know that we’ve found genuine alien microbes?

To address this question, we first need to review the seven fundamental characteristics of life. All living organisms 1) are composed of cells, 2) are ordered, 3) grow, 4) reproduce, 5) pass down genetic information, 6) possess homeostasis, and 7) possess metabolism. In this post, we will consider how growth, reproduction, genetic information, and metabolism are currently used by scientists to detect life both on Earth and in the greater universe.

First and foremost, I am a microbiologist and prefer to follow an old proverb that states, “seeing is believing”. Thus, I would personally be most convinced of life on Mars if I saw an alien microbial colony emerge from a sample cultured on a Petri dish, which would demonstrate the necessary characteristics of growth and reproduction. However, unfortunately this level of evidence is most likely untenable for the foreseeable future.

As an example, on Earth if you directly count the number of bacterial cells from an environmental sample, such as soil or ocean water, using a microscope and then culture that sample on a Petri plate, only ~1% of those bacterial cells will form a visible colony. This phenomenon is known as “The Great Plate Count Anomaly” and has plagued microbiology since its inception. The anomaly is partially caused by how bacteriological medium is prepared, but is more majorly a result of our lack of understanding the nutritional requirements for different individual bacterial cells. Put another way, if we don’t know what Martian microbes like to eat, then we’ll be unable to coax them to reveal themselves.

iChip
Figure 2. The iChip after being removed from the ground. [Source]
On Earth, we’ve developed methods that circumvent and accommodate these picky eaters. For instance, the isolation chip (iChip, Fig. 2) is a relatively recent technology that allows microbes to be cultured in situ (at the place of their origin). This device works by trapping individual microbial cells into tiny wells that are sandwiched between semipermeable membranes. The membranes allow the passage of molecules between the trapped cells and their environment. Thus, the iChip allows microbes to access the nutrients they require without requiring scientists to determine specific requirements and formulate special media. This approach has been used to cultivate up to 50% of the microbes in a soil sample, which led to the discovery of a new antibiotic scaffold from a previously uncultivable bacteria!

Alternatively, as direct culture is a bottleneck for identifying living microbes, culture-independent approaches based on DNA sequencing have exploded in the field of microbial ecology. The primary approach that is used is called amplicon sequencing, which allow us to use specific DNA sequences as barcodes to identify different microbes. An alternative approach is to sequence all of the DNA present in a sample. This approach is called metagenomics and has been used to characterize the genes that are present in different environments on Earth. An advantage of metagenomics over amplicon sequencing is the ability to assemble entire intact genome sequences from environmental samples!

kate_rubins_nanopore
Figure 3. Astronaut Kate Rubins using the Oxford Nanopore MinION Sequencer in Space [Source]
Though once prohibitively expensive and technically challenging, advancements have rapidly decreased the cost of DNA sequencing and shrunken sequencers from the size of a refrigerator to a device that can fit in your hand (which has even been used in space, Fig. 3)! Thus, it may soon be possible to equip our future rovers with their own tiny sequencers. However, there are still important hurdles to overcome before implementing DNA sequence technology. First, direct DNA sequencing can’t distinguish between living and dead microbes. Further, contamination with microbes or microbial DNA from Earth may confound our analyses. Finally, a practical consideration is sampling throughput (the amount of samples that can be processed in a given period of time) and reagent usage.

Whether we attempt to directly culture microbes or sequence their DNA from Martian samples, there’s another practical consideration to discuss: where do we sample? As mentioned above, our rovers will likely carry only a limited amount of reagents for bacterial culture or DNA sequencing. Thus, we need to determine a method to narrow our search space for microbes: we need to identify biosignatures of life.

Fortunately, Curiosity is already equipped with instruments that detect organic molecules. Remember, all living organisms possess metabolism, perhaps we can follow molecules like methane as biosignatures and locate microbes. Unfortunately, because Mars has no atmosphere, the planet surface is bombarded with ultraviolet light, which may destroy volatile biosignatures.

sagan_and_viking
Figure 4. Carl Sagan posing next to a model of a Viking Lander in Death Valley, California. [Source]
As an alternative, we can attempt to identify biosignatures under controlled conditions. One such method was employed in the 1970s during the Viking program. As part of this program, two landers (Fig. 4) were sent to Mars with the mission to search for evidence of life. One experiment performed by the landers was called “Labeled Release”. A Martian soil sample was combined with a mixture of seven radioactive 14C-labeled nutrients and monitored for production of labeled carbon dioxide (14CO2) gas, which would suggest that living organisms had consumed the nutrients and produced the gas as a waste product. The experiment gave mixed results: though both landers initially produced positive results, repeated injections of the labeled nutrients failed to yield additional 14CO2. Though controversial, it is now believed that the 14COobserved in these experiments was produced abiotically. Perhaps future experiments will combine radioactive labeling with culturing or sequencing to identify microbes.

The above list of approaches to identify life is by no means exhaustive. However, I hope this post has highlighted the difficulties that scientists face not only in our search for extraterrestrial life in the universe, but also in characterizing the vast diversity of terrestrial microbes that inhabit on our own planet!

Will you ever meet ET?

By Andrew Anderson (@AndersonEvolve)

One of my favorite shows is Firefly−if you haven’t heard of it, check it out. An aspect of the show I found enjoyable was, despite being science fiction, it explicitly stated there were no known aliens across the regions humans had expanded to. The thought of seeing the results of evolution on another planet would be amazing, and the mental games trying guess at what that life might look like are enjoyable. In reality though, I don’t think we will ever encounter alien life*, much less intelligent life, for a long while (>1000s of years) if at all. I am hardly the first to make such a claim, but I would like to bring up some of the reasons I don’t think we’ll encounter extraterrestrials within anyone’s lifetime.

The best place to start is with Drake’s Equation (see link for details), it’s basically a probabilistic statement made up of dependent chance events and time components. 

eq

Therefore, the chance of each successive event is multiplied by the previous then multiplied by the time that all chance events have occurred. As you can see the Drake Equation includes 6 conditions that have to be met, making the odds of an outcome lower with each condition (e.g. rolling a 1-5 on a die occurs ⅚ of the time, but doing it 6 successive times happens ~⅓ of the time). What’s more, we have no idea what the probabilities are for the later parts of the equation. The rate of star formation and the fraction of stars with planets are able to be reasonably estimated. Everything else is challenging to define. The big issue is we have a sample size of 1. We only know of one planet that formed life, evolved intelligent life, and sent signals−Earth. This is a two-fold problem. If I drew a number at random, what was the probability of drawing that number? Without knowing either how many draws it took or what range of numbers I had to choose from, you cannot know. Additionally, we now have what is known as a sample bias. While we are piecing together how life got started here, is that the ONLY way? Once life begins developing on a planet, what is the likelihood intelligent life appears? We might conclude it’s 100% given what happened on Earth, but remember the majority of Earth’s history is dominated by non-intelligent life*. Humans are a relative blip on the history of life and there’s no evidence that other groups evolved intelligent life. Were it not for a well-timed meteor, there still might not be intelligent life. All of this is to say, we’re not sure how to define all the portions of Drake’s Equation, so anyone claiming it supports their idea (even one saying it’s not possible) is on unstable ground.

Now we can get into some fun probabilistic concepts. Drake’s Equation doesn’t offer much help, but it comes down to a fairly simple question: is Earth, and the process of life on it, rare or common? Some would invoke the mediocrity principle, that is if you only have one observation, it is more likely you observed a common event than a rare one. Imagine it’s your first time snorkeling on a reef; the fish you see are probably the more common fish on the reef. The problem with this is, since we are alive, we had to come from a planet that met the criterion for life, so there is no way our limited observations would NOT include a planet with life on it. I actually think life on Earth could be more along the lines of the Wyatt Earp Effect; given the amount of attempts (planets in this case) it is an almost certainty that 1 will hit on the rare event. Wyatt Earp was notorious for winning gun fights without getting hurt, but given the number of gunfighters and gunfights, someone had to survive multiple gun fights through sheer luck. So life forming could be rare, but it happened at some point and, since we’re here, we see that outcome.

My point so far is we have no idea what the odds of life are, and I acknowledge that my suspicion it’s rare is just that, a suspicion. I think life likely does exist somewhere else out there, but we won’t see it anytime soon because: physics. Let’s assume there is a planet we want to check out for life. There’s a candidate at our nearest star ~4 light years away. Let’s assume that we have a spacecraft right now capable of traveling ~2% the speed of light, the current record is ~1.5%. That means it would take 200 years to reach the planet, plus 4 more just to hear if they found anything. Even if we hit on our first pass, it still wouldn’t happen in our lifetime. Our ability to detect non-sentient life is severely limited and there are no ways to be certain other than direct exploration.

Instead we would have to hope that lifeforms on another planet are sending some signal we can detect, which means they are likely intelligent, or they are likewise looking for life*. Radio waves are electromagnetic waves and travel at the speed of light but there is a delay. Try to imagine a conversation on Messenger where you only see what was written 4 years ago, that’s what it would be like to converse with our nearest star (Alpha Centari could only now tell us how they felt about Lost). This also makes Sci-Fi movies amusing with how communication and observation of events unfold (think about every intense radio conversation in space and how far apart they were–likely they were getting that message minutes or hours after it was sent). Humans have only been sending out signals for ~100 years which means only things 50 light years away could be responding at this point (travel to and from) which is 1/2000 of the distance of the Milky Way. We’ve only been listening for 50 years which means some civilization has to be sending signals at the right time to have them reach Earth in this exact range of listening time*. Consider a planet looking at Earth but is on the other side of the Milky Way, they would not find anything and have to wait 100,000 years just to hear it. All of this assumes we know what to look for or what to broadcast.

In order for us to find life it would have to be close, sentient, and signaling. While the universe is incredibly large, we’ve now severely narrowed our search window, which means life has to form easily and evolve intelligence frequently if we are to see it while you and I are here. I just don’t think that probable. Got something to add or something I missed?* Give me tweet!

Post-Script:

Scott Mattison (@FoolsPizza) added some thoughts (* in text, his thoughts in italics) that should be shared and responded to (my thoughts in bold).

  • I imagine we will find microbial life on colonized planets. I mean, we think we might have bacterial life on other planets in our local system This seems most likely, although we don’t have every step down for the formation. What we do know doesn’t seem like something any other planet would have gone through in its formation. 
  • Non-intelligent or non-sentient or just not up to our levels. It could be reasonably argued multiple forms of sentient life developed on Earth. Humans just won the competition. (Neanderthals vs. Homo sapiens). Also there is the question of intelligence level of apes and dolphins which clearly can learn communicative behaviors In this context I equate intelligence with the ability to send and detect signals to space. This is not at all the correct definition, but for a short piece it’s the easiest term I can think of. Yes, this means humans didn’t become intelligent until quite recently.
  • Fermi paradox –It starts with supposition that life is common and we should see them. I don’t agree with the premise.
  • This gets even worse. EM waves decrease intensity as they spread out through space through the inverse square law (not that inverse square law, the other one).Essentially intensity decreases on the order of distance squared. So even if someone is screaming out into space. They have to scream really loud to appear over the background noise and be screaming in our direction (although we can get pretty sensitive detection especially if they are sending out patterned signals). −Neat.
  • We could also see visible signs from ancient, more advanced races. Concepts of super structures that utilize the energy of their local star would be observable. (we have had some pretty well publicized incorrect interpretations of these things). −It’s still a matter of timing, the ancient civilizations had to have formed at just the right time for us to see, or the structures are durable enough to keep going.  I guess the fun question is does intelligent life persist once it is formed?