Monday, February 8, 2016

Why Ask for Directions? (A Guest Post)

by Anna Schneider

For the iconic monarch butterfly, the shorter days in fall mean it’s time to pack up and head south to a warmer climate! Just like clockwork, the Eastern population of monarch butterflies makes a 2000 mile journey to their winter paradise roosts in central Mexico. The journey in itself is one of the greatest migrations among all animals.

But here’s the catch: none of these butterflies has made this trip before. Several generations of monarchs have come and gone over the course of a summer, but the generation born in late August and early September are genetically prepared for months of survival without feeding or breeding. But their predecessors didn’t exactly leave them with a map. How do they know where to go? Do they have a map and compass inside their heads? The answer: yes! Well, sort of…

Think about this: if you were lost in the woods and needed to find south, what would you do? Here’s a hint: look up! The sun can be a great resource when you’re lost, and I’m not talking about just asking it for directions. As the Earth rotates on its axis throughout the day, the sun appears to travel overhead. By knowing approximately what time of day it is, you can determine the cardinal directions. Monarchs use specialized cells or organs called photoreceptors that respond to light to establish the position of the sun.

Representation of time compensated sun compass orientation used by monarchs;
Image created by Anna Schneider.
Until recently, it was thought that monarchs simply used the photoreceptors on the top portion of their compound eyes, called the dorsal rim. Past studies have shown that the signals are passed from the photoreceptors on to the “sun compass” region in their brains and the butterflies change direction based on that information. Like most animals, it was assumed that their internal clock was located inside their brains. However, recent research has demonstrated that individuals whose antennae have been painted or removed altogether become disoriented when placed in flight simulators. These monarchs do not adjust for the time of day when trying to fly south. When those same antennae that were removed were placed in a petri dish, they continued to respond to light and showed signs that they continued the pattern of time. This indicates that antennae and the brain are both needed for the monarchs to correctly determine their direction.

Diagram of features on the head of a monarch butterfly; Image created by Anna Schneider.
Now, estimating which way is South might be fine and dandy on a bright sunny day, but what happens when it’s cloudy? Not a problem for these super-insects! In another recent study, researchers tethered monarchs to flight simulators and altered the magnetic field conditions to see what would happen. When the magnetic field was reversed so magnetic North was in the opposite direction, the butterflies altered their bearings and flew exactly opposite as well. This suggests that monarchs could have some sort of way to detect the earth’s magnetic field, called magnetoreception, which could enhance the photoreception capabilities.

Many of the mechanisms behind the migration of these incredible creatures are yet to be discovered, but much progress has been made in the past decade. So next time you see a monarch butterfly, take a second look. There is more than meets the eye.

Sources:

Gegear, R., Foley, L., Casselman, A., & Reppert, S. (2010). Animal cryptochromes mediate magnetoreception by an unconventional photochemical mechanism Nature, 463 (7282), 804-807 DOI: 10.1038/nature08719

Guerra, P., Gegear, R., & Reppert, S. (2014). A magnetic compass aids monarch butterfly migration Nature Communications, 5 DOI: 10.1038/ncomms5164

Merlin, C., Gegear, R., & Reppert, S. (2009). Antennal Circadian Clocks Coordinate Sun Compass Orientation in Migratory Monarch Butterflies Science, 325 (5948), 1700-1704 DOI: 10.1126/science.1176221

Steven M. Reppert. The Reppert Lab: Migration. University of Massachusetts Medical School: Department of Neurobiology.

Monday, February 1, 2016

A True Underdog…or Undermouse (A Guest Post)

By Spencer Henkel

People love a good underdog story, and nowhere is that image more embodied than in the rodents that live in deserts. In the desert there are two main problems that animals must face: it is way too hot and way too dry. You would think that rodents, the smallest of mammals, would not have much difficulty surviving in this kind of habitat. You might think that they would need far less food and water than their larger neighbors like reptiles and birds. Unfortunately, this is not the case; in fact, rodents’ small size actually makes life harder for them in such harsh conditions. Rodents gain and lose body heat faster through surface exchange with their environment, their highly active lifestyle requires a lot of food and a high metabolism, which generates a lot of extra heat that must be dispersed, and the distance they can travel to find food and water is extremely limited. Desert rodents must find ways to deal with all these issues, a tremendous feat for such tiny creatures.

Photo of a Golden Spiny Mouse (Acomys russatus) in Israel
by Mickey Samuni-Blank at Wikimedia Commons.

The most pressing concern of any animal that lives in the desert is making sure its body has enough water to carry it through the day. Needless to say, water can be hard to come by in such arid lands, and what water is present is usually found in seeds, tubers, and other plant material. Rodents will find and take in this water, but they face another problem: the contents of their diet are very salty. The rodents must now find a way to get rid of this excess salt while still holding onto a fair amount of water, for they cannot afford to simply excrete a steady stream of urine like we can. They must call upon a chemical from their brain, vasopressin, to help them out with this process. Vasopressin is an antidiuretic hormone, what I like to call an “anti-makes-you-pee”. It is made in the hypothalamus part of the brain, and when called upon it exits the pituitary gland and travels by blood to the kidneys. Once there, vasopressin causes the tiny blood vessels in the kidneys to clench up, slowing the flow of blood and increasing the time water has to be reabsorbed before urine is produced. When Nature eventually does call, the rodents will have made a small amount of urine that rids them of a whole lot of salt.

Now the rodents must turn to the other issue at hand: keeping cool. Water plays an active role in cooling an animal’s body by evaporation through sweating, panting, urinating, and defecating. Unfortunately, as with the salt in their diet, rodents can’t afford to lose all that water if they want their insides to keep functioning. So instead, rodents will lower their metabolisms. This reduces the amount of heat generated inside the body, so their core temperatures will decrease. A lower metabolism will also reduce the amount of water the rodents need to cool themselves down. However, if this process keeps up, the animal could die of hypothermia, ironically. So to keep that from happening, these rodents increase the amount of heat generated by their brown fat, masses of fat found primarily in animals that hibernate. This tissue will keep the animal’s core body temperature stable even when their metabolism slows way down.

In spite of their size, rodents actually have a rather tough time surviving in the desert. Yet they have found efficient ways of dealing with such extreme challenges. They can conserve enough water to live while still filtering out a great deal of salt, and they can slow down their own heat production while maintaining stable body temperatures. It is indeed quite a feat when the smallest of mammals succeeds in living in one of the harshest places on earth!

Sources Cited

SCHWIMMER, H., & HAIM, A. (2009). Physiological adaptations of small mammals to desert ecosystems Integrative Zoology, 4 (4), 357-366 DOI: 10.1111/j.1749-4877.2009.00176.x

Monday, January 25, 2016

Caught in My Web: What the WHAT?

Image by Luc Viatour at Wikimedia Commons.
For this edition of Caught in My Web, we just wonder.

1. Scientists confirm that zebra stripes are not for camouflage… or even to help recognize one another. Anyone got another idea?

2. Want to surf in the ocean without fear of sharks? A shark deterrent wet suit is explained in this TED talk.

3. The woolly mammoth may be brought back from extinction in just a few years!

4. Gorilla treetop slumber antics were caught on tape for the first time.

5. Some towns wake up covered in giant spider webs. Here's why.

Monday, January 18, 2016

Catch Him If You Can (A Guest Post)

By Caitlin Lockard

When playing Frisbee with your dog, do you ever wonder how they have the ability to catch it so effortlessly? The art of being able to figure out where something like a Frisbee is headed requires some crazy math skills. Ostracods are one kind of animal that puts their wicked math skills to the test while finding a mate.

The image above of a female ostracod was provided by Trevor Rivers.

You’ve never heard of an ostracod you say? Ostracods are small crustaceans, which basically means they have lots of legs and are covered by a hard shell. Male ostracods can be seen roaming throughout the ocean trying to enchant females with light displays. Typically, just after sunset, males begin their light displays, which consist of two phases. The first phase is the bright phase, which is short. The goal here is to signal to the female that “I’m here, single (except all my buddies that I brought with me of course) and ready to mingle”. The second phase is where males spiral up in a helix while pulsing repeatedly. This phase is much dimmer and is used by females to choose a mate. But exactly how do female ostracods go about catching the moving and light-pulsing man of her dreams?

Scientists, Trevor Rivers of the University of Kansas and Jim Morin of Cornell University, set off to explore if female ostracods try to intercept the moving and pulsing males or if they just chase them. In order to conduct this experiment, immature female ostracods were collected off the shore of Southwater Caye in Belize. After catching the ostracods, females were put into tanks and raised to maturity, ensuring that all the females were sexually mature virgins. Rivers and Morin put an LED light behind the different tanks in order to mimic an actual mating display. The LED light looked like a string of Christmas lights pulsing from bottom to top, mimicking the males’ helical light display. In the control group, there was an LED light placed behind the tank, however it was turned off. The duo questioned whether or not the LED light show was able to mimic the display put on by male ostracods. Also, they questioned how females respond to the males’ display by measuring the height at which females intercepted the LED light, how straight of a line the female swam in, if the female swam at an angle, and what direction the female swam in. Check out a video here.

The scientists found that the LED light was able to mimic the helical phase that male ostracods put on well enough for the females to respond. Females in the control group merely swam at the same height, as there was no reason for her to waste her energy with no “male” around. However, females in the experimental group had to think on their feet to figure out where their male crush was heading. They swam directly toward but slightly above the “male” than when there was no “mate” around. If the female merely headed to the same spot where her “male” previously was, she would miss him. Instead, she had to anticipate where he was going next and head that direction.

What’s the moral of the story here? If you’re a female ostracod, your man will always be on the move, so you better have some gnarly geometry skills in order to track him down.


Work Cited:

Rivers, T., & Morin, J. (2013). Female ostracods respond to and intercept artificial conspecific male luminescent courtship displays Behavioral Ecology, 24 (4), 877-887 DOI: 10.1093/beheco/art022

Monday, January 11, 2016

How To Get Into An Animal Behavior Graduate Program: Preparing for Your Interview

Congratulations! You have been invited to interview for a chance to be a graduate student. …Now what?

Image from freedigitalphotos.net.

First of all, give yourself a pat on the back. Graduate student positions are highly competitive and as funding dries up, they are becoming even more so. Being invited to interview means that you have done all the right things to grab the attention of a Principal Investigator (P.I., i.e. the person that runs a research lab). At this point, the P.I. has already assessed your application and determined that you have the potential to be productive in his or her lab. Your primary job in this interview is to confirm this view. However, many people forget that interviews go two ways: Your second job in this interview is to assess whether this is the lab where you want to spend the next 4-8 years of your life.

A helpful way to think about interviews is from the perspective of the interviewer. What does a P.I. hope to do by interviewing prospective graduate candidates in the first place? Most P.I.s are limited in how much time they have for mentoring and how many resources they have to support students and their research interests. They want to know that the students that they accept will be motivated, capable, and realistic. They also want to know that anyone new to the lab will get along with current lab members. Ideally, new lab members would also bring in new energy and ideas. To gain insight about where you may fall with respect to these qualities, most interviews for graduate positions include a one-on-one chat with the head of the lab, social interactions with other lab members, and tours of the lab and parts of campus or the geographic area.

Your one-on-one interview with the P.I. is your primary time to convey your passion for what the research lab does and your motivation for being a part of it. This means that you need to do your homework beforehand: Read the lab website (if there is one) and know what the major topics of research are. Read several papers from the lab and have a sense of what techniques they use (The P.I. is usually listed as the last author of papers that are published by lab members). From what you have learned about the lab, have a few different ideas for projects you might be interested in working on if you were a student there. What qualities do you have and what experiences have you had that show that you would be capable to do such a project with adequate mentoring? If you can get the P.I. excited about an idea you pitch, you have a good chance of getting the spot. However, don’t get too attached to your research ideas: They may not be feasible for some reason or perhaps the P.I. only has funding for a student to work on a specific project, so you need to go in with a flexible mindset. You should also ask questions of your own during this time, both to show your serious interest and to assess if this lab and potential advisor are a good fit for you. Here are some questions you may want to ask:
  1. I know you have done research on X, Y, and Z from reading your website and papers, but do you have any lines of research you are currently working on or plan to work on that you have not published yet?
  2. How involved are you in helping your students choose their topics of study?
  3. How do your students learn research techniques?
  4. How are most students in your lab funded? (If you express a willingness to apply for your own funding, the P.I. will be impressed).
  5. How long do most of your students take to get a degree?
  6. Have any of your students left before completing their degree?
All of the lab members will try to assess how well you will likely fit in with the group. Don’t let this freak you out: Just be your natural self, but be careful which self you project: you don’t want to be the version of yourself that relaxes on the couch with friends slinging curse words like a drunken sailor (even if the other lab members are interacting this way with one another). Remember that you are meeting them for the first time, so be the friendly and slightly more formal version of your natural self that you present to Grandma or church. Also use this time to get the “real” scoop that you may not get directly from the P.I. Some good questions to ask lab members (when the P.I. is away) are:
  1. How is the P.I. as a mentor? Have you or anyone else had any issues with the P.I.?
  2. What are other lab members like?
  3. What is it like to be a graduate student in this program?
  4. What is the area like?
  5. Where do graduate students live? What is typical rent like?
  6. How hard is it to get funding as a R.A. (research assistant) or T.A. (teaching assistant)? How difficult is it to balance R.A. or T.A. responsibilities with classes and research?
Don’t forget that as the lab is trying to assess whether you would be a fit with them, you should assess whether they would be a fit for you. Are there opportunities to do research that you find interesting and to gain skills that will be useful to you? Is this a place and a lifestyle that you think you would be happy in for the next several years? And perhaps most importantly, does the P.I. have a personality and mentoring style that will help you grow as a person and as a scientist?

As for what to wear, dress business-casual and appropriate for the weather. There will likely be a lot of walking around, some outside. Scientists are a practical bunch and will not likely be impressed with your fancy outfit if it does not exhibit common sense. On the other hand, they will think you lack motivation if you show up in tattered jeans and a sweatshirt. Wear something semi-professional and comfortable.

Now get out there and knock their socks off!

For more advice on applying for graduate programs, go here.

Monday, January 4, 2016

When The Going Gets Tough, The Tough Become Babies

Today I am giving new young life to a post from 2012. You can find the original here.

We celebrate the New Year as a time of rebirth, renewal, and do-overs. We join gyms, swear off our bad habits, and promise to be better people. This is especially true for those of us that have had a rough 2015... Our 2016-version-of-us has got to be better, right? But what if you could get a real do-over? What if you could be a kid again, grow up again, and become a brand new person? As far-fetched as it may sound, some animals do exactly that.

Cnidarians (the "C" is silent) are a huge group of aquatic animals that includes jellyfish, corals, and anemones (like the one Nemo lived in - Yeah, that tentacled home was a living animal). They are named after prickly plants known as nettles, or cnides in Greek, and if you touch one you will quickly know why. Cnidarians, armed with stinging cells called nematocysts, sting at the slightest touch.

Jellyfish make up many of the cnidarian species, and they have been found in every ocean and at every depth. Some even live in freshwater. The "typical" jellyfish life cycle starts when eggs and sperm are released into the water and find one another. When they do, they form larvae, which you can think of as baby jellyfish. The larvae sink and settle on a hard surface, where they mature into polyps. These polyps are jellyfish in a juvenile stage. The polyps elongate and begin to bud off adult medusa, which are the bell-shaped blobs with tentacles that most of us think of when we think of a jellyfish. Medusa mature to become reproductive adult jellyfish.

The jellyfish life cycle by Zina Deretsky at the National Science Foundation (NSF). Image available at Wikimedia.

Larval and polyp jellyfish are much more resistant to harsh conditions then are medusa jellyfish. When life gets hard for a jellyfish, perhaps because of starvation, physical damage, temperature changes or salinity changes, those that are in the larval or polyp stages can often shrink and rest in a hibernation-like state while they wait for more favorable conditions. But in some species, young adult medusa can even regress back to the juvenile polyp stage. By reverting back to a juvenile stage, they have more protection from the challenging world around them.

In most cases, this reversal to a juvenile state can only happen in young medusa that have not yet developed their gonads. Thus, the onset of sexual reproduction (puberty, if you will) might be regarded as the point of no return in development. However, one species, called the immortal jellyfish, has shown that this rule can be broken.

As an adult medusa, the immortal jellyfish is a pea-sized jellyfish with a round bell, bright red stomach and anywhere from 8 to 90 tentacles. It is currently the only known animal that can regress from a fully reproductively mature adult into a juvenile polyp. If exposed to dangerous conditions, immortal jellyfish medusae completely reduce all of their medusa-specific organs and tissues and develop new polyp-specific tissues, essentially becoming kids again!

This figure from the Piraino et al. 2004 paper at the Canadian Journal of Zoology shows the life stages of the immortal jellyfish. The adult medusa is in panel (a). Panels (b) and (c) show the medusa tranforming to a ball-like blob as it reverts to a juvenile stage. The green stain in these panels shows the cells initiating this transformation. Panel (d) shows the remnant of a medussa, and the black arrow shows the stalk that is common in the polyp stage. Panel (e) shows the resulting juvenile polyp.

But wait! It gets better! Theoretically, if an animal can revert to a juvenile stage at any point in its adult life, it could attain immortality. But if that were true, they would have the classic immortality problem: These animals would reach such high populations they would saturate the world's oceans...And this may actually be happening.

Immortal jellyfish are thought to originally be from the Caribbean, but they have since been discovered worldwide and their populations seem to be growing. Likely, they are hitching rides in the ballast water that is sucked into cargo ships to provide stability. If this is true, the immortal jellyfish polyps could be attaching to the ships' hulls and settling in for a long voyage to a new home.

We don't yet know if the immortal jellyfish are actually immortal, but it is fun to consider that they might be (although they can still be killed by predators or viruses, so they're not invincible). And we can take inspiration from them: When the going gets tough, try reverting to your more resilient juvenile self, but be thankful you don't have to go through middle school again!

Happy New Year!

To learn more, check these out:

1. Piraino, S., De Vito, D., Schmich, J., Bouillon, J., & Boero, F. (2004). Reverse development in Cnidaria Canadian Journal of Zoology, 82 (11), 1748-1754 DOI: 10.1139/z04-174vv

2. Miglietta, M., & Lessios, H. (2008). A silent invasion Biological Invasions, 11 (4), 825-834 DOI: 10.1007/s10530-008-9296-0

Tuesday, December 29, 2015

Our Most Popular Posts of 2015

To celebrate the end of the year, I compiled a list of The Scorpion and the Frog's most popular posts of 2015. If you missed them, check them out here:

#5. Gut Feelings explains new research that shows that the microorganisms living in our guts can affect our behavior in mysterious ways.

#4. In Vole Pee: An Epiphany, Nate Kueffer talks about how birds of prey use ultraviolet vision to see pee-trails of their prey.

#3. Prepare to be amazed! Enjoy The Weirdest Animals on Earth: 12 Amazing Facts About Octopuses.

#2. Rachael Pahl tells us about some crazy bug sex in The Bed Bug’s Piercing Penis.

#1. In The Beginnings of Jurassic Park: Dinosaur Blood Discovered?, Sam Vold contemplates the real science behind Jurassic Park.

There have been some fascinating animal stories by many great science writers. Here's to many more stories in 2016! Happy New Year!

Monday, December 21, 2015

Caught in My Web: All About Dogs

Image by Luc Viatour at Wikimedia.
For this edition of Caught in My Web, we celebrate our wonderful canine companions.

1. Nina Golgowski at HuffPost Science explains research that shows that dogs give treats to their doggy friends, but not to doggy strangers.

2. Rafael Mantesso's wife left him and took everything but the dog and the empty white apartment. Rafael found inspiration in his predicament and created some of the most wonderful photos ever! Check them out here.

3. Let puppies teach you about complexity theory in this TED talk by Nicolas Perony.

4. Virginia Hughes at National Geographic shares research that shows that dog brains process voice information similarly to our own.

5. And just for fun, here is Bella the dog singing “Jingle Bells”:

Monday, December 14, 2015

Why Are Cats Scared of Cucumbers?

Have you seen the video of cats’ terrified responses to cucumbers? No?! Then check this out:


This hilarious video has led many people to try this on their own cats… to varying degrees of success. And it has led to some curious questions: Why are these cats so terrified of a cucumber? And why isn’t my cat?

The fear of something specific (like a cucumber) can either be innate (as in, you’re born with it) or learned. For many animal species, it would make sense to be born with a natural fear of something that can kill you the first time you encounter it, like a steep drop, being submerged under water, or a venomous snake. Some of these things can be so dangerous that an animal with a fear of anything that even resembles it may have a higher chance of surviving long enough to produce its own fearful babies some day. So maybe these cats have an innate fear of snakes that has caused them to respond in this hilarious way to anything that resembles a snake… like a cucumber?

But if cats have an innate fear of snakes, why don’t they all respond to cucumbers this way?

Sometimes fears appear to be innate, when they are actually learned. For example, in 2009, researchers Judy DeLoache and Vanessa LoBue at the University of Virginia explored whether the fear of snakes is innate in human babies with a series of three experiments.

In the first experiment, Judy and Vanessa showed 9- and 10-month old babies silent films of snakes and other animals and they measured how long the babies looked at each type of film. Presumably, a baby will be more vigilant of and spend more time looking at something they are scared of. They found that the babies responded exactly the same towards the snake films than to the films of other animals.

Next, the experimenters showed the babies the films of either a snake or another animal again. However, this time they played the audio of a person sounding either happy or frightened along with the video. The babies looked at the non-snake animal videos the same amount regardless of whether the audio sounded happy or scared. However, the babies looked at the snake videos longer if the audio sounded scared than if the audio sounded happy.

In the third experiment, the experimenters repeated this pairing of audio with visuals, but this time they used still pictures of snakes and non-snake animals instead of videos. This time, the babies did not react differently to the snake or non-snake animal pictures depending on if the audio sounded happy or scared.

This shows that, at least for people, we don’t have an innate fear of snakes, but we do have an innate tendency to develop a fear of snakes if we are exposed to the right combination of hearing someone being afraid and seeing a moving snake. In other words, some fears are more contagious than others. And this isn’t just true for people: a study of rhesus monkeys found that baby monkeys raised by parents that were afraid of snakes only developed a fear of snakes themselves if they observed their parents acting fearful in the presence of a real or toy snake. So perhaps, the cats in this cucumber video saw or heard someone being fearful of something cucumber-like (or snake-like) when they were young... Or maybe they were just surprised by something sneaking up on them while they were eating.

In any case, don’t be too bummed if this hasn’t worked on your cat… Maybe try it on your friends instead!


Want to know more? Check these out:

DeLoache, J., & LoBue, V. (2009). The narrow fellow in the grass: human infants associate snakes and fear Developmental Science, 12 (1), 201-207 DOI: 10.1111/j.1467-7687.2008.00753.x

Mineka, S., Davidson, M., Cook, M., & Keir, R. (1984). Observational conditioning of snake fear in rhesus monkeys. Journal of Abnormal Psychology, 93 (4), 355-372 DOI: 10.1037/0021-843X.93.4.355

Monday, December 7, 2015

Are GMO Fish Safe for the Environment?

Photo of an Atlantic salmon by Hans-Petter Fjeld, licensed under
the Creative Commons Attribution ShareAlike 3.0 License and
available at Wikimedia Commons.
The U.S. Food and Drug Administration (FDA) recently approved the first genetically engineered animal for food consumption, AquAdvantage Salmon, a salmon strain developed 25 years ago by AquaBounty Technologies. The FDA determined that this salmon strain is as safe to eat and as nutritious as other wild-caught or farm-raised Atlantic salmon and they have provided strict guidelines as to where and how these fish can be farmed (authorizing only two specific facilities, one in Canada and one in Panama, to breed and raise them). These fish will likely soon be in our grocery stores and restaurants, despite the resistance of many environmental and food-safety groups as well as skeptical grocery chains and citizens. What exactly are these animals and do they pose a threat to our environment?

Today at Accumulating Glitches, I talk about genetic engineering, GMOs, and what scientists think about whether AquAdvantage Salmon pose a risk to our environment. Check out the whole article here.