Thursday, December 5, 2013

A unicorn whale? That can't be a thing.

This week, I watched the movie “Elf” to get into the Christmas spirit. Among the highlights:
  • “You stink. You don’t smell like Santa. You smell like beef and cheese."
  • “We elves try to stick to the four main food groups: candy, candy canes, candy corns and syrup.”
  • "Have you seen these toilets? They're GINORMOUS!"


Buddy the Elf finds out he is a human living amongst Santa's elves, explaining why he always felt he just didn't belong. Buddy realizes he must set out to find out who he really is, and that means finding his birth father. As Buddy leaves the North Pole to find his dad in New York, he sets adrift on an iceberg. As he pushes off, a Narwhal surfaces.



When I saw this scene, I realized I didn’t know what the heck a Narwhal was. I knew it must be a marine mammal, a kind of whale. But a unicorn whale? That can’t be a thing.

A quick internet search showed me that they are real. Narwhals and Beluga Whales are the only extant species within the family Monodontidae- latin for “singular toothed.” They live in the Arctic Ocean (hats off to the writers of “Elf.” They got their Narwhal facts straight.) They were originally described by good ole’ Linneaus and get their common name from the Norse word for “corpse.” Apparently, their grey, speckled skin reminded people of dead sailor corpses. Romantic, no?

Let’s talk about that horn. Really, that horn is what made me wonder if Narwhals were real. I mean, it’s not uncommon to see mammals with paired, keratinized outgrowths like horns and antlers. And the rhinoceros even has a singular horn on its snout. But a marine mammal? How is that efficient when swimming? In a watery, swimming environment, how would a singular horn function? Male to male combat would be hard to imagine, as sheep and deer are on ground and can brace themselves against impact from one another.

Come to find out, the “horn” is no horn at all. It is a tooth, or a tusk, that grows through the whale’s lip. And only the males have it. It grows from the left side of the upper jaw, while the right canine tooth remains an undeveloped nub. (Although, it is worth mentioning that 0.2% of male Narwhals develop both the left and right tusk). And to add weirdness to an already weird situation, the tusk is highly enervated. They can feel things with it.

Narwhals tusking. (wikicommons)
Naturalists have debated for a long time what purpose the Narwhal’s tooth serves. They have rarely been observed fighting each other with the tusks, nor attacking other species or using it to break sea ice. They have been seen participating in a group activity known as “tusking,” where males get together and rub tusks.

It is largely held that the tusk is a secondary sexual characteristic, meaning it serves little physiological purpose and exists almost completely to attract mates and establish mating rights. Kind of like body hair on human men. It exists as a secondary sexual characteristic- not really that useful, but attractive to us ladies on a primal level.

Males with big tusks get preferred mating rights with the female whales (fewhales! new word.) of their choice. And the tusking thing probably exists to establish hierarchy amongst males.

I hope this post weirded you out as much as it did me. Narwhals, though fascinating and intricately evolved, make me sort of uncomfortable.

But, if they are as nice as the one in Elf, then maybe they aren’t so bad.


Hope you find your dad.

Sunday, November 10, 2013

tiny dancer in my hive

(Yes, that was a Sir Elton John reference.)

I’m fixing to blow your mind.

Honey bees utilize basic geometry and perceive quantitative distances and angles.

And they communicate with each other about it.

OH look. A little poster you should print out!
Bees live socially, and the workers forage for nectar to bring back and make honey with. After a bee finds a source of nectar in a patch of flowers, it returns to the hive with the good news. But how could a little bug like a bee communicate something as complicated as an outside location? Hormones can say primal things like “me angry, me attack!” or “me horny!” But “upon exiting the hive, fly 45 degrees to the right for about 2 kilometers, at which point you will then arrive upon bountiful flowers and nectar?” How is a bee supposed to say that?

The bee does a little dance, called a waggle dance. Let’s put ourselves in a bee’s shoes for a minute. Say you just found a nectary patch of daisies and arrive back at the hive.

First step in the waggle dance is to cling to the side of the hive and acclimate yourself however many degrees from the vector for “up,” or the opposite of the pull of gravity, according to how many degrees from the direction of the sun you found the nectar. Say you went 45 degrees to the left of the sun to find your daises. In that case, you turn your body 45 degrees to the left of up. Okay- now you’re ready to boogie.

Now, you waggle your butt as fast as you possibly can and walk a straight line along your angle. It’s very important how long you take to do this; you’re telling the other bees how far away the flowers were. One second of this waggle phase represents one kilometer of distance. So, if you waggle for a quarter of a second, then you’re telling everyone that the flowers are 250 meters away.

Next, you turn to the right and walk back to your starting point. Do another waggle, and turn to the left and loop back to your starting point. However many times you do this tells everyone how worth it it is to find this nectar. If you found a butt load of nectar, you’ll want to waggle plenty of times to get your point across. Otherwise, a few waggles will do.

And this actually works. This is an actual thing that bees do. Bees are mathematically perceptive. To me, this is totally insane.

Also, what makes this story cool, is that the bees give a damn at all. So many times in the animal kingdom, you see intense resource competition amongst conspecifics. Like when an eagle finds a fish and has to fight other eagles from taking it away from him. Or when a mean girl asks me where I got my brand new cute shoes, I’m going to lie and tell her WalMart. (I’m not proud. But don’t be scamming on my cute shoes! I worked hard to find them on zappos.com.) Why should bees give away their nectar findings to each other?

But bees are social animals, and structured into social tiers. Worker bees exist only to collect nectar for the good of the hive. Workers cannot reproduce, and therefore have no real motivation to be selfishly competitive for resources. Their instinctual interest is that of the hive, making working together essential. Ah lah, the evolution of this amazing cooperative communication system.

Saturday, November 2, 2013

lots and lots of babies


I am at that age where my Facebook feed constantly offers up pictures of engagement rings, weddings, and lots of babies. Lots and lots of babies.

While some of my fellow single ladies find this to be a tad annoying, I don’t mind so much. It’s nice to see good things happening for good people when they’re ready for said good things to happen. Even if those things are kind of red and wrinkly and a little gross looking. With weird heads.

When you look at pregnancy patterns across Mammalia, you see a wide variety of systems. Rats have a gestational period of just over two weeks, while elephants can take 2 years to develop in utero.

Humans take, on average, 40 weeks to develop before birth. It’s long been thought that this timeline is determined by female pelvis size. Basically, that babies pop out right before their heads grow too big to fit through the birth canal.

Long ago in our evolutionary history, before we stood on two legs, we were quadrapedal rodents running around birthing multiple babies at once. But as the millennia passed and we rose to walk on just two feet, our pelvises had to evolve to support an upright posture. It narrowed so as to balance our distribution of weight. The tradeoff here was females no longer being able to (comfortably) give birth to multiple, or more developed and not-so-helpless offspring.

This interpretation was long held, and even suggested that gestation had to shorten in duration especially for the human lineage as intelligence evolved. With bigger brains came bigger heads, making birth essential earlier in the pregnancy timeline. This too would be a tradeoff- a newborn with only a small percent of its brain development completed makes for a very helpless little nugget of neediness.

New findings suggest that evolving a wider pelvis would not be disadvantageous to females. Walking and running is not compromised, and only 3 extra centimeters would be needed to produce babies with 40% brain development at birth (which is more than we currently average). Though it sounds scary, an extra 3 centimeters is statistically not that far-fetched. Evolutionarily, it’s actually pretty doable.

So why end the pregnancy party so early? Why not let it bake for a little longer, ensuring a more precocial offspring?

Scientists recently took a different approach to understanding gestation length in humans. They compared body size to gestation length in different species of primates. Homo sapiens actually break the mold, gestating longer than primate patterns would predict. That’s quite different than the suggestion of the previous model: that human gestation was shortened to accommodate babies with bigger brains. So females are pushing our bodies to the limits—but if not pelvis width, what are those gestational limits?

Evidence suggests those limits are metabolic. Our bodies are capable of supporting spurts of metabolic activity about 2 times that of resting metabolism. By the third trimester, a woman’s metabolism is already running at twice its normal rate. Those last few months are extremely taxing on a woman’s body. By 40 weeks, the baby is requiring nutrients and energy at a rate that a woman simply cannot satisfy past 40 weeks or so.

The article posted on livescience.com ends on a thoughtful note- suggesting that maybe helpless offspring aren’t so bad after all. And that makes sense; a brain that comes into this world with more than 60% growing capacity has room for learning through experience. There are some advantageous survival behaviors that simply cannot be programmed into your brain at birth- like the fundamentals of cellular biology that help you understand the need to clean and disinfect a cut. Or how to grow crops and feed yourself and your family. Or how to use tools that build homes and provide shelter. Our blank baby brains are part of what makes us arguably the most successful species on earth. They give us the capacity to learn.

How amazing it is that all of these factors are tied together- the evolution of bipedal locomotion, to brain size, to pelvis width, to the capacity for in utero brain development, to the evolution of higher intelligence and consequently the ability to feel emotion. Perhaps the most beautiful factor in the evolutionary story of our brains is the ability to appreciate warm fuzzy things that seemingly have no bearing on us or our chances for survival. Like cozy, happy feelings you get from Christmas time, or a bouquet of flowers from someone who loves you, or even warm fuzzies from Facebook photos of friends holding their perfectly ripened, 40-week old bundles of helplessness.

Here’s a link to the original article, written by Stephanie Pappas of Livescience.com. She writes good stuff- read more of it.
http://www.livescience.com/22715-pregnancy-length-baby-size.html

Thursday, September 19, 2013

my own personal tun


I know what you’re thinking. You’re thinking that I’m just another lazy blogger. That I’m going to give you the good ole’ “things have just been so crazy!” routine. That I might tell you things like “the summer time here in Alaska has been insanely busy and I haven’t had the time or energy after work to write.” Or even “I rather be out fishing or jogging or hiking in the beautiful weather we’ve been having than inside on a computer.”

Hogwash.

The truth: I’ve been in a suspended state of animation. I am, in fact, part water bear.

Oh hey there, water bear. (www.bbc.co.uk)
Water bears are real. They are tiny little animals part of Tardigrada, also called Tardigrades (but water bears is much cuter so we’ll go with that.) They live in water, typically in mosses and lichens and other damp biological environments. When they are full grown, they are about this long:

-

They are segmented, and have 8 little legs with little claws on each.  They molt, poop, eat, and lay eggs just like real animals (they technically are real animals, but, I mean, look at them. C’mon.) They eat plant material and bacteria, some of them being considered predatory. *Cue mental image of a water bear stalking and killing a bacterium. Adorable.

Perhaps the most fascinating aspect of Tardigrades is cryptobiosis. That is to say, they can be in suspended animation, of sorts. You can dehydrate them, hang out for ten years or so, sprinkle some water on them, and they’ll spring back to life like nothing ever happened. It’s akin to hibernation- an extreme decrease in metabolic activity. When a water bear enters one of these “hibernations,” it is called a tun.

It gets even cooler. They can survive the vacuum of space. NASA took some up and let them orbit around the earth for 10 days, brought them back, and rehydrated them. Almost 70% came back to life within half an hour.

Outer space exposure has other implications about their extreme hardiness: they are able to withstand extreme UV exposure, radiation, and temperature. They’ve been found to survive temps almost as low as absolute zero, where all motion (and theoretically, existence) ceases to over 300 degrees Fahrenheit. (Guess cooking your baked goods thoroughly doesn’t ensure that you get all the water bears out... crunch crunch crunch.)

Basically, as far as reading and writing go, I’ve been in my own personal tun these past few months. But really, can you blame me?

My tun in photographic form.
As the days are getting shorter and the weather less conducive to frolicking, I feel my creative juices starting to surge again. I’ve been perusing Google scholar for new papers to read as of late, and the urge to write is returning with the cooler weather and the fall rain.

Consider me rehydrated.

Here is a link to video of a water bear shot by friend and fellow science nerd Roger Birkhead.
https://plus.google.com/photos/105079444770532704475/albums/5393208005336375857?authkey=CLrI6sa28JOWqQE

Friday, May 24, 2013

shut up you stupid little birds


Sunset outside my bedroom window
Here in Alaska, the days are starting to get pretty long. I crawled into my bed last night and watched the most beautiful sunset- at about 9:45 at night. That post-sunset glow lasted until about 11:00. Then, I woke up this morning to the sound of birds chirping and the world filled with sunshine- at 5:00 AM. Starting my day off with the thought “shut UP you STUPID LITTLE BIRDS” is becoming pretty routine.


Even down south in the lower 48, there are noticeable differences in day length in the winter versus the summer. Days are longer in the summer, shorter in the winter. I used to look forward to Louisiana summer days when I could stay out waterskiing until 7:00 at night. I’d have just enough time to come in to shower and relax my tired muscles, then walk back out to the seawall to watch the sunset around 9:00. These hot summer days were very different those cold winter days of high school, walking in from school at 4:00 and it already starting to get dark outside.

So what is the deal with the changing day lengths throughout the year anyway? Why do we here in southeastern Alaska get mostly dark with a few hours of light in the winter, and vice versa in the summer? Why do the poles get 24 hours of one or the other? Why is it less noticeable as you approach the equator?

The earth is leaning. The axis around which it spins is tilted. Towards the sun, away from the sun, you ask? Well, that depends on what time of the year it is.

We earthlings make one complete trip around the sun each year. During the summer, the northern hemisphere is leaning towards the sun. By the time we’ve made it to the other side of the sun in the wintertime, the northern hemisphere is leaning away from the sun. The result of this lean is that certain parts of the globe spend a little more time in the shade than others, while others spend a little more time in the light. This is a hard thing to visualize, so let’s turn to some pictures.

Shadow zones in the winter time
In the picture above (set in our winter time), you can see that the North Pole stays in the shadow of the earth. Areas a little lower, like Alaska, skim into the light just long enough for the sun to peak over the horizon. This trend continues to weaken as you approach the equator.  The equator gets 12 hours of day every day, all year. Once you get south of the equator, then you’re spending a more and more time in the sun until you approach the South Pole. It’s summer there, getting 24 hours of light. But just wait 6 months, and the roles will have gradually reversed.

Light zones in the summer time
We’re in that role-reversal phase right now. The summer solstice, June 21, marks the northern hemisphere’s maximum “lean” towards the sun- the longest day of the year. After we get past that, the days will start getting shorter as we head back into the dreaded shadow zone. Living so far north, this time of the year drives me to embroider after work and watch Lord of the Rings, in my very own vitamin-D depraved Gollum-like transformation. By the time March rolled around this year, I was turning my nose up at taters and losing pigmentation.



Luckily, sleep masks and blackout curtains help during the summer. Socializing and reading help to resist the call of the One Ring in the winter. As they say, life is a series of tradeoffs.


I took this at noon one day in November, my precious.

Saturday, May 11, 2013

spermy prom hair


Last Saturday, I had the pleasure of accompanying some folks as they caught hooligan- these little silver fish that are currently spawning here in the river. I helped to bag them up and in the process, got covered in their sperm (I couldn’t be mad- we did interrupt them mid-spawn with their little zippers down). Afterwards, I tagged along to drop by the local high school prom to check out the dresses (and seeing as I was super excited about this, I’d say I’m adjusting well to small-town Alaskan life). But the highlight of the weekend was being able to tell my mom the next day on the phone “last night I went to the prom and got sperm in my hair.”

Currently, these hooligan fish are swimming up the Chilkoot River here. They’re pretty little silver fish with tones of pinks and purples. They’re pretty general looking, which makes this occasion a perfect opportunity to relay a little general fish morphology.

Fins
Hooligan fins

Fins are the evolutionary answers to fishy locomotion. Pectoral and pelvic fins project from the body and can move in a rotational manner, acting as little steering arms for the fish.

The dorsal fin can occur in one part or two parts, with the more anterior fin always being the primary one and the back one usually being smaller and squishier. In the case of the hooligan, there are two dorsal fins. The dorsal fin(s) act as sails for the fish, slicing through the water with lateral surface area that pushes against the water on either side of the fish. This keeps the fish from tipping over, keeping it right side up. The anal fin functions in balance as well, in charge of more refined adjustments to keep Mr. Fish from tumping over.

Lastly, the caudal (caud being latin for tail) fin is the big daddy in the back that swings from side to side to move the fish forward.

Lateral line

You can peer into the water and see these hooligan swimming against the current in their little groups. They seem to almost have telepathic abilities- knowing and reacting  instantaneously to what their fish friends are going to do. Have you seen those nature shows that show schools of fish all turning and darting in what seems to be perfect unison? How do they do it?

When you look at fish, you’ll notice a faint line that runs down their sides. This is called the lateral line. Lateral lines are actually a series of nerve clumps that act as a composite sensory organ. On the surface, the lateral line is a series of sensory epithelial cells that hook up to the underlying nervous system, which translates the sensations felt by the surface cells to electrical impulses that are sent to the brain. These sensations are caused by minute pressure changes in the fish’s immediate environment. The flick of a neighboring fish’s tail, the opening jaws of a nearby predator, or the creeping legs of a delicious crustacean- the lateral line allows all of these things to be sensed without being heard or seen.

Gills

Gills are NOT underwater versions of lungs. They are entirely different structures from different origins, but do have the shared function of oxygen acquisition. In fact, they are quite superior in this area, what with their countercurrent oxygen exchange and all. Just looking at a fish, you usually don’t get a glimpse of these delicate, feathery gills. They are covered up and protected by a bony covering called the operculum. If you were to snap this off (of a dead fish only, don’t be mean!), you could then see the feathery, vessel-laden projections that serve as oxygen exchange sites for the fish.


So even though fish are slimy, they’re still worth getting to know. Living underwater presents a whole different set of challenges- but not to worry. These little guys have got it covered. Much like I was in their sperm.

Sunday, May 5, 2013

wear thick panties just in case


After I graduated few years ago, I was working at a national park and living in a beautiful country house out in the middle of a Louisiana cornfield. It was a historic home, built in the 1840’s. I’d crawl into bed each night, surrounded by memories of generations of Creole culture. It was a beautiful experience. But one thing about a rural Louisiana home in the summer: bugs. Lots and lots of bugs.

Bugs are not beloved animals. Of course, there are entomologists and naturalists who find friends amongst the arthropods. And then there are the moth-loving Buffalo Bill types (it puts the lotion on its skin or else it gets the hose again). But most people either feel unkindly towards or downright terrified by our jointed, exoskeleton-bearing cousins. Spiders don’t bug me so much (see what I did there?), but put a roach or flying insect in my room, and I will immediately start crying like a girl. I appreciate them when viewed through glass or in a book, but for the love of all that is holy, keep them away from me.

I was climbing into bed in my little summer home one night, exhausted and ready to konk out. All of the sudden, a horrible, stinging pain hit my right ass cheek. I flew out of bed, and lo and behold: a red wasp was buzzing around the bed. It had crawled in between my sheets and was waiting for my bare hiney to climb into bed before stinging the living daylights out of it. I couldn’t sit for 24 hours after that horrible incident.

(Wikicommons)
Not long after that, I was reading before bed when “buzzzz buzzzz,” a humongous, black, loud, fast, and terrifying cicada started flying around the house. I mustered up all my courage to approach the beast with a broom. I tried to beat it to death- didn’t work. So I cornered it and drenched it in wasp spray. The monster subdued, and certain that it was dead, I put it in the trash. I fell asleep soundly, knowing the nightmare was over.

Sometime during the middle of the night, I was stirred awake by a sound that struck terror in my heart. The beast was somehow still alive, making its sound from inside the trashcan. Panicked, I put the entire trashcan outside on the porch, locked the door, got back into bed, and put a pillow over my head. Rocking back and forth in fetal position was not enough to put me to sleep that night.

Since then, I’ve felt a little guilty about my behavior towards this cicada. I’ve learned a little more about them since. They aren’t so bad. Yes, they still strike fear into my heart, but it’s not their fault. And their calls are perhaps one of the most comforting sounds in the world to me- it takes me back to porch-sitting, sweet-tea drinking, ceiling-fan spinning summer sunsets back home.

One particular genus of cicada has a fascinating lifecycle. Magicicada lays its eggs in tree bark. After a few weeks, the little nymphs crawl out of the nests, down the trees, and underground, where they stay for 17 years. In the soil, they spend their time maturing into adults. Long, sub-terrenean incubation periods are not uncommon for cicadas, but Magicadas are special because theirs are synchronized. This means that instead of a batch emerging each year, each generation emerges at the same time. For a few weeks, this huge population of newly emerged adults breeds like crazy and then dies. When you figure in the 17-year incubation period, it means that every 17 years, a huge emergence of horny cicadas occurs. And folks, 2013 is one of those years.

Mmmmm.
In a few weeks, the eastern seaboard will be covered with Magicicadas of the Brood II (several colonies, or broods exist across the United States). My good friend from Virginia enlightened me to the hipster culture surrounding this occurrence. She told me that people like to dare each other to eat them and that they taste like “cold, canned asparagus.” I know: oh my god.

What a strange event this seems, millions of bugs coming out of the ground all at once. Literally, all at once, in a single night. And so many! Densities have reached up to a million and a half PER ACRE. It’s truly a massive invasion. Why in the world would this genus of bugs have such a drastically different lifecycle from even its closest cicada relatives?

This is a strategy called predator satiation. You see, these cicadas are prey species. They are eaten by birds, raccoons, spiders, lizards, you name it. But by occurring in such massive bursts, predation can’t put much of a dent in their numbers. Predators can eat until they can’t fit another bug in their mouths and the Magicicada population is relatively untouched. Predators love these kinds of reproductive events- they absolutely gorge themselves, eating until they are in a stupor. Other animals exhibit this sort of reproductive strategy in coordination with predation (salmon runs satiate bears), but this Magicicada business is truly extreme.

Can you imagine being a Magicicada? You spend seventeen years growing underground, only to emerge for a few weeks to have sex and then die. I mean, it seems more reasonable for things like gnats, whose entire life spans no more than a matter of days. But an insect, living longer than your average dog, and accomplishing no more than reproduction during that span is remarkable.

Here’s to wishing the Magicicada Brood II luck in its impending emergence. They may be kind of icky, but bugs are really cool. That being said, I hope there is not a wasp, or a cicada for that matter, waiting in your bed for you tonight. Wear thick panties just in case.

Here’s a great, interpretive website that can tell you more about these little suckers.

http://www.magicicada.org/magicicada_ii.php

Sunday, April 21, 2013

cut in half and slightly souped up


There are certain advantages to being a man. More upper body strength means you don’t have to find someone to help you lift the flat tire you just changed all by yourself into the trunk, even though you know how to do the whole thing by yourself but just aren’t strong enough to pick up the dang tire (what, I’m not bitter). Negotiators take men more seriously (not saying it’s fair, but it’s true). Men are statistically way less likely to be mugged or assaulted. But at the end of the day, men are inherently lacking in an area that women aren’t: genetic material.
Female allosomes on left, male on right. Notice the DINKY,
 LITTLE, Y. (http://www.brusselsgenetics.be)

You have 23 pairs of chromosomes- one of each pair coming from one parent. One pair represents your allosomes, aka “sex chromosomes.” If you’re a boy, you got a “y” chromosome from your dad and an “x” chromosome from your mom. If you’re a girl, you got an “x” from your dad AND an “x” from your mom. So, girls= xx and boys = xy.

That Y chromosome is really key in determining sex. It is way smaller than the X chromosome, and doesn’t really carry too much information on it aside from the most vital male-determining genes. It contains a gene, called the SRY gene, that “turns on” maleness/testosterone production. You see, being female is like the default condition. The presence of a y chromosome lays the groundwork for being male, but the activation of its SRY gene is what actually drops the ball(s). (Which, by the way, are really ovaries that were told to descend and produce sperm by the SRY gene). So, morphologically, all embryos start off as female and then are changed into male once the Y chromosome kicks into action.

The X chromosome carries way more DNA, including sequences that are not directly sex-relevant.  Yes, there’s DNA for instructions on building ovaries and eating Ben and Jerry’s once a month (don’t forget, men have this too on their X chromosome, but that Y turns on the maleness that covers up the female condition). But there’s also genes for more unfortunate things like the recessive male-patterned baldness and colorblindness.

Women carry these genes all the time. But since they’re recessive, the trait is not expressed unless a very unlucky lady happens to get them on BOTH her X’s. And that’s just not very likely. But if a female who has colorblindness in one of her X chromosomes gives that X to her son, he’s screwed. That scrawny little Y from dad doesn’t have enough punch to combat the trait like a girl’s extra X would. This is why color blindness and male-pattern baldness are almost exclusive to men. Since he got the X from his mother, he knows that one of her parents is responsible. If it was her dad, he will have expressed the trait. This kind of inheritance is called sex-linked inheritance.

So really, an XY is just a cut-in-half and then slightly souped-up version of an XX. Ladies, we may not have enough testosterone to lift a tire into the trunk, but we have enough DNA to keep colorblindness and pattern baldness at bay. We win… this one.

Tuesday, April 16, 2013

i need more sticky notes


I work at a small natural history museum where we receive lots of museum catalogues. Last week, a copy of the 2011 “Bone Clones” product catalog found its way into my hands. Let’s just say that I’ve spent way too much time flipping through it and putting sticky notes on pages that have cool stuff. They've got all different skulls from all different humanoid species. They've got bird skeletons. They've got eggs. They've got reptile and amphibian skeletons. They've got extinct animal bones. I can't even handle it.  I’m going to have to buy more sticky notes.

I love bones. They tell stories- yes, stories in the cheesy “NCIS” forensic way- but they tell more expansive stories too. Bones have been our clearest windows into our evolutionary past. With technology advances, DNA sequencing is becoming the front runner. But bones, I think, will always be the most tangible (and my personal favorite) way to unravel our past’s morphological secrets.

I would like to share with you a few of my favorite human bones- all of which are part of the spine. Our spine is important in that it fostered the major changes in our posture when we became tetrapedal land animals, and then eventually bipedal humans.

Atlas (wikicommons)
The top two vertebrae in your spinal column hold special significance. At the tippy top of the spinal column is your C1 vertebra (first cervical)- known as the atlas. Right below it is the C2 (second cervical) vertebra, called the axis. These two vertebrae are shaped in a way that allows for way more movement than other vertebrae. By articulating against the skull and each other, these two bones allow you to nod and turn your head. Notice how the Atlas has two contoured dips where the skull rests and may articulate, rather than a fused spinal-cerebral junction like you see in fish. (Poor fishies can't nod yes or no, can they?)

Axis (wikicommons)
Way back when we were fishies on our way out of the seas, emerging land animals like Tiktaalik would hide from predators in the shallows. But our fish predecessors were not well-built for air-breathing in the shallows. To make air breathing easier, nose holes migrated to the top of the head and the atlas began to form, allowing it to tip its head up and out of the water. And so, we left the water for drier prospects. As life diverged on land, predatory and prey niches were filled and binocular vision developed, moving eyes to the front of the head and limiting peripheral vision. The Axis stepped in to allow for more side-to-side head movement, allowing for more efficient predation AND predation evasion.

Hyoid (wikicommons)
Not far from your atlas and axis hangs the hyoid bone. The hyoid bone is not the most well known, because it is often missing from skeletons and skeleton drawings. This is because it is unconnected to the rest of the skeleton. It essentially floats in the throat area, suspended only by muscles and ligaments. If you press on the underside of your chin and back a little, that’s about where it is buried. The hyoid bone itself is an evolutionary descendent of a gill arch- a cartilaginous support structure found in the gills of fish. In us, it serves as an anchor for the back of your tongue so you can say words. (On a cheesy NCIS note: the hyoid bone almost never gets broken unless someone tries to strangle you. So fractured hyoid = homicide by strangulation.)

Coccyx (wikicommons)
The coccyx, or the tailbone, is the very last bone in your spine. It’s more of a “bone unit,” actually consisting of several fused vertebrae. Way back in our primate histories, we had tails. As we climbed out of the trees and onto the plains, they disappeared in our current primate lineages. But they left the coccyx remnant- hence the name “tailbone.” Now they’re only good for bruising, breaking, and the occasional vestigial-tailed mutant baby.

If I could choose one art project to work on for the rest of my life, it would be cataloging and illustrating every single vertebra in every major vertebrate family. They themselves are strange little works of art, their contours and projections both beautiful and telling of their function.

But if I don't ever find a life-long job opening for "vertebrae drawer," I'll just name my kids Atlas, Axis, Hyoid, and Coccyx. They'll hate me forever, but man, what cool names they'll have.

Friday, April 5, 2013

lavender candles and toilet handles


Today was one of those wonderful days. It was sunny and gorgeous outside, I got a ton done at work, and I had one of those rare but oh-so-satisfying, single-girl, “I just fixed something that broke without having to ask for help” moments when I installed a new handle/lever arm in my broken toilet. Small victories, people.

I wish you could smell
through the internet.
The best part of my day was undoubtedly receiving a care package (from my soul-twin, of course) that was full of goodies like herbal tea, cozy socks, fancy office supplies, facial masks, and chocolate. Nestled in this little box of heaven was this lavender and eucalyptus aromatherapy candle (left).

Lavender has been used in a medicinal capacity for millennia.  It helps aid relaxation, can ease dermal irritations, alleviates pain, and acts as an antiseptic. It’s easy to grow at home, and smells absolutely divine.

Once upon a time, doctors noticed something fishy going on with young boys and lavender oil. Several pre-pubescent boys were experiencing gynocomastia, clinically known as “boob development.” The onset of this breast development coincided with all of the patients’ use of a topical ointment with a principal ingredient of lavender oil. Was lavender oil inducing estrogen production in these kids?

Lavender in bloom (sloatgardens.com)
Yes, come to find out. A study by Henley and Korach (2010) confirmed that several essential oils, the most common of which being lavender and tea tree oil, routinely cause “endocrine distrupting activity”- aka they mess with your hormones. Specifically, your sex hormone estrogen. They considered both estrogen production and the different estrogen receptors in mice to see at what level the lavender was acting. They found that lavender exposure actually enhances expression of estrogen-producing genes. This means that lavender actually causes your cells to read the DNA blueprint for estrogen at a greater rate, flooding the system with excess estrogen.

Men have estrogen too, just as women have testosterone. They just have them in different proportions. So, both genders are vulnerable to the estrogen-spike that lavender exposure can initiate. Naturally, it is more noticeable in the sex with lesser estrogen. Luckily for those poor kids in the study, the gynocomastia subsided with decreased lavender exposure. Phewph. So if you are a guy, don't go shooting up with lavender oil unless you want to start wearing a bra.

Here’s to fixing stuff on your own, having wonderful friends who take care of you from 3,000 miles away, and hoping that my new candle will induce gynocomastia to help a sista’ out if ya’ know what I mean.

Or at the very least, that it will induce some aromatherapeutic relaxation while I soak in my tub wearing a facemask and listen to Enya, all the while admiring my new toilet handle out of the corner of my eye.

Wednesday, April 3, 2013

Myer-Briggs voodoo magic


Have you ever taken the Myer-Briggs personality test? It’s the one that gives you four letters, each representing some part of your personality. We had to take one our senior year of high school as a way to help point us to potential career choices. The questions seemed completely arbitrary- i.e. Do you like to sit to the left, center, or right of a room? I remember thinking what a crock it must be as I finished it up and turned it in.

A few weeks later, our teacher hands us back our sealed envelopes with our results. I read mine, astounded that this test understood me better than anyone I’ve ever known. Well, better than anyone except my best friend Ashley- who coincidentally sat right behind me. (Ashley and I call each other “soul twins”; in a world where we feel quite different than most, we just get each other). I spun around to discuss the results of this voodoo magic with her. And would you believe it, she and I scored the exact same personality type. The rarest type at that- making up 1% of the population. If that doesn’t verify a friendship, I don’t know what does.

In previous posts, we’ve talked about how behaviors evolve. But personalities- where do they come from? Are they genetically linked? If so, did natural selection act on them during the development of our species? Did personality evolve?

I did some research into the evolution of personalities. There are a bunch of scientific papers on it. In general, most of them say that there is evidence that many personality traits are genetically linked, but there are so many variables involved that it is an abstract and a “poorly understood” mechanism. Translation: it's likely. But we can’t figure it out yet.

Somewhere in our history as tribal animals, social hierarchies emerged. Maybe, each tier in the social hierarchy can be thought of as a niche, and each individual as a particular species. Individuals had to divergently evolve to reduce competition for a singular niche, making it easier for each social role to be filled.

What if everybody in a tribe was super outgoing, or overly dominant? There would be fights and pissing contests all the time- that wouldn’t work very well. What if everyone kept to themselves and didn’t share ideas? That wouldn’t work very well either. Is it possible that this could have been the groundwork for the evolution of personalities? Populations of humans with wider ranges of temperaments and social roles were the most successful?

Who knows? Maybe. Even if it was, then a lot has happened to complicate and deepen the human personality since then.

This post answers zero questions, and raises a bunch. But I kind of love it when science hasn’t yet figured out something. Not knowing things allows us a sense of wonder that answers don’t. It’s amazing how different people can be, and thank goodness for it.  My sister and I, for instance, are as different as night and day. But I couldn’t have asked for a more complimentary sibling counterpart. And I know that I could never marry someone just like me. We’d read books on weekend nights and never be forthcoming with our thoughts or feelings. Regardless of how they came to be, personalities help make our world go ‘round.

If you haven’t taken the Myers-Briggs test, there are a few online. They’re not as thorough as the official one, but I at least scored the same on both. After getting your score, consider: if you had been Tuk-tuk in the early ages of human, what social role might you have filled?

Here are the links to a couple tests:

Tuesday, March 26, 2013

musical memories


Y’all- rarely do I blow my own mind. But tonight, I did just that.

I was typing the word “accept” and had to momentarily consider whether it or its homonym “except” was appropriate. The thought train took me to “accept is a verb” and “except is a …. what is it?…. ah yes, preposition.”

And then, I spontaneously busted out in a song that I have not heard nor sang in sixteen years. You see, my third grade language teacher made us memorize all of the prepositions by putting them to the tune of Yankee Doodle. Catchy little song. I aced my English test on prepositions and have not thought about that song since.

Yet sixteen years later, I am able to perfectly rattle off those forty-six arbitrary words in perfect alphabetical order. That song was in my brain all this time. Untapped, unused, but unchanged. How can this be?

video

Remember our chat about neurons? Well, their little fingers are called dendrites. These dendrites are what reach out and make connections to other neurons. The number of dendrites per cell is plastic- meaning your neurons can grow or lose dendrites- and therefore connections- according to how much the present ones are used (do a Sodoku puzzle tonight! Grow some dendrites!). These connections are what constitute your memories. Fire one chain of them off, boom: your fifth birthday party. Fire a different combination of connections off: that Halloween you lost your wallet and walked home in the rain, maybe sort of inebriated, dressed as Chewbacca. Your recollection of your life’s experiences is a complex network of chemo-electric signals. That’s insane, right?

A study in the mid-90’s looked at memory and music. And boy, are they correlated. Text recall was significantly better when set to the tune of a song than when simply spoken. However, it was significantly worse when just one verse was sung or when plural melodies were introduced in a single song (Wallace 1994). From this, we can conclude that it’s not just rhythm that enhances our dendritic connections- it’s actual music. Be it a stupid yet catchy tune (“Call Me Maybe,” I’m looking at you and your stupid lyrics), or soul-moving sounds like Mozart’s Requiem.


It’s can be unsettling that memories of things like your first kiss or precious time with loved ones that have since died are nothing more than very specific paths of action potentials traveling from neuron to neuron in that hunk of meat we call a brain. But the fact that they are solidified by music makes it easier to stomach- at least for me. “Party in the USA” takes me right back to margaritas in my college apartment, laughing with my girlfriends so hard I couldn’t breathe. “Leave” by JoJo puts me right back in my sister’s Jetta, making late-night summer trips into Bossier City to get soft serve ice cream from the McDonald’s drive-through. I can put on Rachmoninov’s second concerto, about halfway through the first movement, and be transported back to my father’s strong hands on the steering wheel as he drove me home from my first year in college- and actually feeling the sense of content safety I felt then.

And that, to me, is simply beautiful- dendrites and action potentials included.


Wallace, Wanda T. Memory for music: Effect of melody on recall of text. Journal of Experimental Psychology: Learning, Memory, and Cognition, Vol. 20 (6). Nov. 1994, 1471-1485

Tuesday, March 19, 2013

walker texas ranger tears




As I sat and ate my grilled cheese sandwich on my lunch break not long ago, Walker Texas Ranger played on the TV. Walker’s girlfriend, Alex, has survived being kidnapped and almost killed, and is now lying in a hospital bed while he lovingly comforts her in all his ginger glory. He tells her how much she means to him, and then pulls a ring out of his pocket. And there it is… “Alex, will you marry me?”  It pans to the highlights of their relationship. In typical cheesy 90’s slow-mo style, Alex and Walker stroll through fields hand in hand, laugh together, cry together, and share loving looks into each other’s eyes as their perfectly teased Texas hair blows in the breeze.

And suddenly, I am bawling.

The credits begin to roll and I brush my tears off of my grilled cheese and wipe my eyes. Something isn’t right- I should be laughing hysterically, not crying hysterically. I look at my calendar on my phone and then it makes sense.

Let me tell you folks, hormones are very real. They don’t only control your mood- they control things like sleep, friskiness, stress response, fight or flight response, puberty, hunger, parenting, and in-utero develepment. Pretty much every process or event your body undergoes is driven by hormones in one way or another

But how do they work? Having to direct things from slow-paced things like ovulation to fast-acting processes like adrenaline rushes, how do they make things happen? Where do they come from? Where do they go? How do they get there?

Hormones are little molecules that are manufactured by your body. They can come from individual cells, organs, or more frequently from glands (think thyroid, testes, ovaries, adrenal, etc.). Different glands manufacture different hormones.

Major glands  (wikicommons)
To name a few: Testes and ovaries manufacture sexy hormones that influence puberty, ovulation, parenting, menopause, and male machoism. Your adrenal glands sit on top of your kidneys and produces adrenaline- key in stress response, fight or flight, and cell metabolism. Your thyroid gland in your neck manufactures a variety of hormones, mainly affecting metabolism. The big daddy gland- the pituitary- is buried at the base of your brain and is perhaps our most primitive gland. It regulates just about everything from sleep to sex drive. The pineal gland, also of primitive origin, plays a role in light detection and internal calendar regulation.

From their respective glands, hormones are released into the bloodstream in order to travel to their target tissues. Let’s take adrenaline, for example. Say you’re walking down a dark alley and all the sudden a man steps out in front of you with a knife and says “give me your money!” Time for fight or flight response. Your brain immediately sends signals down to your adrenal glands, which then flood your whole body with adrenaline. But you only need certain tissues to respond, right? Your cardiac muscles need to quicken, your pupils need to widen, your blood vessels need to dilate so you can haul ass. Well, nature has it so that only these target tissues have receptors to recognize these hormones. So while your pinky toe is getting the same dose of adrenaline, it don’t give a $h*t. But the cells of your heart and blood vessels certainly do- and respond to help you get out of this hairy situation. This is how the whole hormone system can be so refined- receptors only exist where their hormones are meant to act.

The guy with a knife is still standing in front of you. You kick him in the balls and run. You make it safely away and stop to catch your breath. That jittery feeling that makes you ready to punch somebody in the face is the adrenaline coursing through your body. Within the next few minutes, you’ll start to feel more normal. This is because the adrenaline is being cycled out of your cells and metabolized to the point of no longer being hormones.

The system is pretty much the same for slow-release events like ovulation and puberty. Your pituitary regulates your internal calendar, activating the right tissues at the right time.

When you break it down like this, it all sounds so scientific and straightforward. But when you’re sitting next to a lady with a baby on an airplane and are desperately hoping she’ll ask you to hold it, or crying at Walker Texas Ranger, it doesn’t feel so scientific or straightforward. Makes you wonder how much of the human experience is just molecules binding to receptors. But then again, maybe that makes it that much more extraordinary.

Monday, March 18, 2013

have you SEEN a dik-dik?





A recent and actual G-chat transcript, between my sister and me.


Alix: Have you SEEN a Dik-dik?

Me: No. What is a Dik-dik?

Alix: A tiny tiny antelope.
             They are monogamous.
They can run 26 mph.
Can you imagine if a Dik-dik ran past you at 26 mph?

It would be amazing.

I wish lap giraffes were real.

Okay got to go. Love you bye.



Of course, I immediately Wikipedia’ed Dik-dik, and was faced with the cutest ungulate I’ve ever seen.

OH MY GOD. (wikicommons)
They are little antelopes that live in Africa. They eat small plants and shrubs, throw it back up, chew it some more, and eat it again. This would be gross, but they’re so tiny that it’s more funny than it is gross.

What really caught my eye in the Wikipedia article was the blurb referring to their monogamy. It reads:

“Monogamy in dik-diks may be an evolutionary response to predation; surrounded by predators, it is dangerous to explore, looking for new partners.”

Monogamy exists all throughout the animal kingdom. Selective pressures vary in each instance of it, but it is safe to make the sweeping statement that monogamy usually evolves as a means to protect highly vulnerable young. Take us, for example. The survival rate of babies (before the present-day civilization) must have been waaaaay higher if Dad stuck around to protect mom and child from saber-toothed tigers and to help provide food. On the other end of the spectrum, consider a housefly. Baby houseflies are ready to buzz off and start life as soon as they hatch. Mom and dad aren’t even around- they’re already off having irresponsible sex with new partners. Monogamy wouldn’t make sense for them.

Dik-dik being sassy. (pbase.com)

Never before had I seen monogamy explained as a response to predatory danger for the parents. No way this could be true, I thought to myself. I researched further, and lo and behold: a whole paper has been published on Dik-dik monogamy. And they found something pretty interesting.

It had been previously assumed that Dik-diks were facultatively monogamous. Facultative monogamy is monogamy that is the result of restrictions on resources. In other words, male Dik-diks could only defend enough territory to accommodate one female, and that’s why they only mated one female. If more resources were available, then the male Dik-diks could afford to pimp two or more females.

Researchers found evidence to the contrary of this model. Male Dik-diks routinely defend territory (and therefore resources) to accommodate several females! Why do they date just one lady, then?

Obviously, because they have the capacity to love. (Alix, you stop reading here. Life will be better if you do.)

No, that’s not true. Rather, it’s because the males are jealous little suckers and don’t want any other guys picking up their girlfriends. It’s formally called mate guarding- and is an evolved behavior that increases the likelihood that their genetic material is passed on to the next generation. If Dik-diks had the equivalent to “The Maury Show,” the audience would be sorely disappointed that Dik-diks rarely question the paternity of their fawns. Daddy Dik-diks keep close enough eyes on their ladies that they’re not too worried about it.

This being said, monogamy rarely occurs in nature without extra-pair copulation, aka “getting some on the side.” In Dik-diks, only males will engage in extra-pair copulation. Mated females are noted to rarely, almost never, engage in extra-pair copulation (go figure).

So, several components contribute to Dik-dik monogamy. It is safer for the tiny, herbivorous animals to stick to their territory instead of going down to the local drinking hole to try to meet new Dik-diks. Also, mated pairs spending almost all of their time together increases paternal fidelity. And even though males have the capacity to mate more females, they don’t- the lingering urge to mate guard has been passed down from earlier times when perhaps the Dik-dik male could only defend territory for one female.

My initial balking reaction to the explanation of Dik-dik monogamy was short-sited. It wouldn’t make sense for the natural world to be as diverse and multifarious if evolution followed a blueprint. Regardless of how many notes I took or outlines I made about monogamy as an evolved reproductive strategy while I was in college, I don’t know diddly squat.

When asking questions about the evolution of life, always remember to keep an open mind. If researchers hadn’t kept open minds about Dik-dik monogamy, we’d still be without the knowledge that males mate one female, even though they can mate more. And I prefer to live in a world where Dik-diks stick by each other's sides in a non-obligatory capacity. Don’t you?





Here's the paper:

Female dispersion and the evolution of monogamy in the dik-dik. Brotherton, PNM, and Manser, MB. Animal Behavior, 1997. Volume 54 (6), 1413-1424.


Friday, March 8, 2013

put your science panties on (part 2)

 Last time, we covered the first part of the journey a neural signal takes on the way to becoming muscular movement.  We started at the brain and made it all the way down the nerve highway to a muscle. And it is here at the neuromuscular junction that you have been waiting with bated breath for the tale to continue.

When an action potential makes it to the end of the nerve road, it must make something happen in your muscles. The electro-chemical energy of the action potential must be somehow translated into kinetic energy. While your muscles are capable of creating large-scale movements like swinging a golf club, the tiny movements of the molecular structures of your muscles is where this kinetic energy is translated. So let’s get up close and personal with muscle structure.

Your muscles are like bundles of cords within bundles of cords- kind of like Russian nesting dolls- bound together by connective tissue. When you get down to the cellular unit, a single muscle cell is called a muscle fiber. A single fiber is made of smaller units called myofibrils. It is in these myofibrils that the basic contractile units of muscles are found. This basic contractile unit is called a sarcomere. Sarcomeres are made up of long proteins that slide past each other to make the muscle contract. These two stringy proteins are actin and myosin.

A relaxed sarcomere
Myosin filaments have these little bulbs hanging off called “myosin heads.” The myosin heads like to link up with the actin filaments. Through a process involving some supplementary energy molecules (holla, ATP!), the myosin heads creep along the actin filaments, bringing them closer together. Think of a little army guys (myosin heads) climbing along a rope (actin). This is muscle contraction on the tiniest level.

Contracted sarcomere

So, imagine that a whole bunch of sarcomeres are crammed into a muscle fiber. And a whole bunch of fibers are crammed into a single muscle. You’ve got tons of sarcomeres, working simultaneously, causing a whole chunk of muscle to squeeze in on itself.

Well that’s all well and good. But how is it that we’re so coordinated? I wouldn’t call Beyonce’s performance in the video for Single Lady “chunks of muscle squeezing themselves.” I mean, one muscle group is capable of a wide variety of motion, so there must be more nuance to it than  “chunks of muscle squeezing in on themselves,” right?

Right. This is where we go back to part 1- the innervation of the muscle. The complex maze of nerve fibers feeding muscle is responsible for the precise control we have over our movement. Your brain can selectively fire the pathways that feed just part or parts of a muscle. These different combinations are what make a smile different from a frown, from an inquisitive facial expression, from an embarrassed expression, from an amused expression. All use the same muscle groups, but each stimulates them in a different pattern.

The complex neural to motor pathway, to me, is one of the most intricately wired processes in all of Vertebrata, but always funnels down to one of the most basic: the little sarcomere. 

Wednesday, February 20, 2013

put your science panties on (part 1)


Let me warn you before you embark on this post: it’s a little more technical than usual. We’re going to cover the mechanics of both your nervous system and your muscular system, in our first ever two-part blog post (ooooh, aaaaaah!). So unless you have a solid 20 minutes or so, I suggest saving this one until you are at home with a cup of hot tea with Wheel of Fortune on in the background.

It’s easy to avoid thinking about how your muscles work because it can be an overwhelming thought. How complex they must be to be capable of lifting heavy things and also finite tasks like writing! And even MORE mind-boggling is the system that connects your brain to each and every muscle cell in your body. How in the cornbread hell can a simple thought turn into an intent, and then turn into an action? How can you go from thinking about scratching your head, to intending to scratch your head, to scratching your head? It is confounding.

Your brain has highways reaching out to all of your skeletal muscles. These highways are your nerves. Most of them exit your skull and travel along your spine in that clump called the spinal cord. From there, they branch out to your muscles.  A single one of these nerve cells is called a motor neuron, and is not a blob of a cell like you usually think of.  It has a body and a long skinny “stem” called an axon. They’re long and skinny because- well, they’re highways! In fact, the longest single neuron you have runs from the base of your spine to your toes- up to a meter long. Think of the motor neurons a giraffe has!
Figure 1: A single neuron.

These highway nerve cells are uniquely structured for carrying signals- chemo-electric signals- from your brain to your muscle cells. Your brain tells your muscles what to do via your nerve signals. But these signals are not “encoded” with information- one signal does not vary from the next, nor do they vary in strength. It’s kind of like binary code- it’s either a 1 or a 0. In this case, there’s either a signal, or there’s not. Your neuron fires, or it doesn't. One single signal is called an action potential.

An action potential is basically a change in voltage of the membrane of a nerve cell. It’s like this wave of voltage that travels along one nerve cell, setting off the one after that, and the one after that, and the one after that, and- well, you get the picture. But these nerve cells- their membranes in particular- are specially built for carrying action potentials.

Alright y’all. Time to put your science panties on. It’s about to get real up in here.

The inside of the cell is negatively charged, in respect to the outside of the cell. Positively charged potassium (K) and sodium (Na) ions are floating around, both inside and outside of the cell. There are little pumps in the membrane are constantly pumping these ions against their concentration gradients in and out of the cell to maintain a high concentration of K and low concentration of Na inside the cell- which maintains an internal charge of about -70 millivolts. This is called resting potential.

Figure 2: The basic set up of the axon of a neuron: The movement of Na+ and K+ ions  through channels and a pump
across a the membrane cause depolarization, repolarization, and hyperpolarization of the cell membrane (aka an action potential)

Now, let’s say the neuron’s dendrites become excited enough to set off an action potential. Little voltage-dependent sodium channels will open up, allowing sodium ions to diffuse along their gradient- into the cell. This influx of positively charged ions raises the inside voltage. This part is called depolarization, since the cell is becoming, well, depolarized.

Once the inside of the cell reaches about 40 mV (notice, that number is now positive!), sodium channels close and their neighboring voltage-dependent potassium channels open. Then, the potassium ions have their turn to diffuse along their gradient- out of the cell. This exodus of positively charged ions then causes the intracellular voltage to drop- bringing it back down into the negatives. These potassium channels are a little sluggish, though, and take a while to close. The cell hyperpolarizes a little past the original -70 mV, but is corrected quickly by the trusty Na/K pumps.

This process happens as a wave, traveling down the axon of a neuron. To help the process, a material called myelin wraps around the axon (Fig.1- the white bead looking things). Myelin is white (that’s why the neural tissue of your brain is white… white matter!) and is an insulator. This allows the action potential to skip right through the insulated bits, speeding up transmission to lightening fast speeds. That time you almost dropped your phone in the toilet but caught it right in time? Yeah, those lightening fast reflexes were thanks to myelin.

Once a neuron propogates an action potential all the way down to the terminal buttons, it sends chemical signals (neurotransmitters) out to the next neuron in line and excites its little dendrites- starting the process over. This occurs all the way down to the intended muscle site. And there, the muscle must take this action potential and turn it into kinetic motion. And kinetic motion is WAY more exciting than ion diffusion- so, stay tuned!

Now, I know that if you’re reading this part, you’ve read this entire blog post. And for that, faithful reader, you deserve A TREAT. To claim your treat, simply leave a comment stating your name, and I will write you a poem. And yes, it will hurt my feelings if no one takes me up on my poetry offer. FYI.