Sunday, December 14, 2014

the little titmouse that could

I’ve had some big life changes happening recently. I made the hard decision to leave Alaska to move back home to Shreveport. I got an awesome new job working in science education.  I feel like I have a sense of family again. I’ve reconnected with old friends and made some new ones- one of which is a mouse of the tit variety...

Tufted Titmouse
You see, I moved back in with my mom. I’m lucky to have a soft place to land until I get my own apartment next month, but there’s a reason you get shoved out of the nest at 18. It has been good to spend time with my mom though. And a little unexpected friend has been hanging around the house.

When I first got home, I would hear this knocking sound a few times a day that echoed throughout the house. I could not believe it when I found the source of this perpetual racket- a little Tufted Titmouse was perching on the windows, peeking in, and pecking them with its beak. It would beat on one window for a few seconds, then flutter to the next and repeat.

And it has not stopped. As I type this, I’m watching him do it.

Tufted Titmice are songbirds. They’re known for their melodic call that sounds like someone singing “peter-peter-peter.” They’re small, generally bluish-gray with blush-colored contour feathers under their wings. They have big black beady eyes that dot their pointy little heads, which are crested. You’ve seen plenty of crested-headed birds before; think Blue Jays, cardinals, waxwings, etc.

Crests on songbirds function mainly in display. They are more prominent on the males, and serve as signal of fitness. Other birds have even fancier crests, like cockatiels. Evolutionary biologists have good evidence that suggests they were present on the dinosaur ancestors of birds. A T-Rex with a plume of feathers on its head? Yes please.

So why is my new friend being such a creeper? I really don’t know. Maybe he’s a person that’s been magically turned into a bird and is trying to get my attention for help. Maybe he can see inside and is curious. It’s more likely, however, that he sees his reflection and is trying to pick a fight with himself (I find that endlessly hilarious). At any rate, I admire his tenacity- he certainly does not give up.

As I start this new chapter of my life, I’ll take notes from this little titmouse that could. Don’t give up, keep trying your hardest, and always pick a fight with your reflection.

Ya know, for the entertainment factor.

Friday, October 31, 2014

have a creepy crawly halloween

In observance of this spooky holiday, we’re going to talk about something truly terrifying. Something that can make your skin crawl… something that goes bump in the night (albeit a tiny bump)… something that will try to suck the blood right out of you.

If you haven’t guessed, I’m talking about ticks. Those blood-sucking, privacy- stealing, creepy crawling arachnids.

I may be a little tick-sensitive at the present time. I just arrived back in Louisiana a few weeks ago and have already had red bug bites and one tick. Red bugs are one thing; they itch like crazy but you really don’t have to treat the bites. But when you find a tick on you, you have to physically remove it. Here you are, minding your own business, only to find out this little invertebrate has been on your person for several days, burrowing into your skin, and feeding on your blood. It was on you when you were going about your day like a clueless dope. You feel violated.

This bite looks to be a case of Lyme disease
transmission. But also, just kill me know.
And now, NOW you have to remove it with tweezers. You can’t just say, “hey, Miss Tick, I know you’re just trying to make a living, but I’m going to need you to please move elsewhere. What’s that? You’re happy to leave? Okay, thank you! Take care!” No no. You have to carefully tweeze it off, being careful not to smoosh it. And if you’re like me, you will of course accidentally smoosh it and not get the whole thing out.  And then you’ll feel disgusting and like a disease-ridden reject. And so goes life.

Obviously ticks cause me, among other people, a little anxiety. But like all living creatures, they are pretty cool in some ways. For one, they are not insects. They are arachnids- more closely related to spiders and scorpions than they are “bugs.”

Because they are so tiny, we often assume they do not have complex behaviors: that they wander their environment aimlessly until they find a host and dig in. But that is not so. They have a pretty cool system for food searching that is a classic reference case in ethology (animal behavior).

You see, animal behaviors are based off of releasers. A releaser occurs, then a behavior results.  For instance, a lizard flashing its red dewlap would be the releaser for female arousal. An animal running away quickly would be a releaser for a grizzly bear to pursue it. A Lord of the Rings marathon would be a releaser for Claire sitting in front of the TV watching it.

The presence of carbon dioxide and heat is a releaser for tick “questing” behavior. They sit perched like tiny gargoyles on the edge of leaves, waiting for a passerby. Once they sense increased levels of CO2 or heat in their immediate environment, they grip onto the source with their legs. This would make sense, since mammals breathe out CO2 and put off a fair amount of body heat.

In fact, biologists that research ticks use this knowledge to their advantage. They will put white sheets down on the ground and spray CO2 canisters around the underbrush. The ticks fall off onto the white sheets like little drunk idiots.

How many millions of years did it take for this releaser/behavior to be selected for? A million? Maybe less. I would think there would be a strong advantage for ticks that exhibited this behavior.

At any rate, hold your breath when walking through the forest. Wear clothes that insulate your heat.

And if you find that impractical, then invest in some tweezers and Xanex.

Saturday, September 13, 2014

drink some water and go home

My high school calculus teacher was fabulous. Fabulous because of her cute outfits and fun sense of humor, but mostly because of her incredible gift for teaching math. Mrs. Weiss made custom notes, homework, quizzes, and tests that set us up for success. She taught us the ideas behind calculus, not just how to solve calculus problems. She taught us the why. By the end of the year, I could see functions and graphs forming in my head after just glancing at numbers or problems. Don’t tell my mom, but my trick in college was to do integration problems in my head at the bar. When I couldn’t integrate anymore, it was time to drink some water and go home.

On the very first day of class, Mrs. Weiss told us “calculus is the study of how things change.” That didn’t sink in immediately, but I understood it over time. And last night, as I struggled to find my keys in the dark, it popped into my head again.

Here in Alaska, summer is sadly at an end. Fall is in full swing, and the day lengths are changing. I got home last night a few minutes after 9:00, as I usually do, and for the first time since summer had to use a flashlight to find my key. It’s that dark now. How does something so gradual and metered sneak up on you all at once? It seems like such a noticeable change all of the sudden. (In my earlier blog post shut up you stupid little birds, I touched on how the whole season changy, day length changy thing works and how it’s exaggerated at extreme latitudes.)

As I turned the key to my dark apartment, a graph popped into my head. An infinite sine curve. The graph of how the day length changes must be a beautiful, perfect sine curve.

In calculus, the derivative of a function is the rate at which something changes at any given point along that graph. If we want to know at which time during the year the changes in day length are greatest from one day to the next, we look at the derivative.

On our graph to the right, the path of the graph levels out to almost not changing at all around the solstices (June 21 and Dec 21). This means the derivative is 0 or very close to it right around the solstices, and that the sun may only set or rise a matter of seconds later or earlier than it did the previous day.

The derivative is greatest on September 23 and March 20 (the equinoxes). You can visually see here that the graph is taking a steep nose dive/climb.  Here in Haines, there may be more than five minute or so difference in how much daylight we get from day to day around the equinoxes.

So maybe I’m not crazy for thinking the days seem to be getting really short all the sudden. The autumnal equinox is in a matter of days, and the change is especially noticeable because we’re losing daylight at a faster rate than we have been all year. The graph is plunging.

It’s worth noting that yet another function can be tied into this little story. Depending on what latitude you live in, you see this day length change at varying magnitudes. At the poles, 24 hour light/night is experienced, which would mean the peaks of the graph are higher and the valleys are lower. It also means the derivatives are greater. Conversely, at the equator, they experience 12 hour days and 12 hour nights year round, so there are no peaks and no valleys. Their graph is completely flat.

So what is the derivative of the graph for the folks that live on the equator where there is no change in day length?

If you can’t tell me, you need to drink some water and go home.

Friday, September 5, 2014

an elegant tango

Throwback in high school.
Tiny little arms.
My whole life I’ve been skinny. Like, get called into the counselor’s office because they think you have an eating disorder skinny. Like, strangers think it’s acceptable to say “eat a sandwich!” instead of “nice to meet you” skinny. Like, eat two Big Macs and large fries and still lose 5 pounds skinny.

I’ve been steadily putting on weight since high school, about 3 pounds per year. I rarely weigh myself and instead focused on taking in as many calories as I could to climb my way out of the “underweight” section on that chart at the doctor’s office. “One day I’ll fill out and be able to sit on hardwood floors,” I told myself.

So you can imagine my surprise when I stepped on the scale a few weeks ago and saw that I’ve gained 15 pounds in about 6 months. I mean, I’ve kind of been noticing some more padding in my belly area as the rest of me has stayed thin. I’ve been kind of proud of my hard-earned fat. But when my sister saw a photo of me and asked if I was “prego,” it dawned on me that I need to regulate how and where I continue to gain my weight.

Men and women are shaped differently, in large part due to fat distribution. Classically, in art and otherwise, women considered to be most beautiful are those with little waists and bigger hips. Science set out to quantify this, and found there is in fact a golden ratio to tell you how hot you are (as if the rest of the world and media didn’t already assume that role).

The results are in and turns out that men find women with waists that are 70% the circumference of their hips to be most attractive. It is thought that this ratio signifies the most fertile women that are best built for carrying and delivering a baby. Makes plenty of sense, right?

Consider evolutionary signals, as discussed in my earlier post stop it, your bib is turning me on. An itty bitty waist and a round thing in your face may often actually signal a fertile woman, but not always. Think of how many women today struggle with infertility, many of them proportioned according to the 70% rule. So is the 70% rule an honest signal of fitness? Has modern medicine and birthing protocols tampered with the honesty of this signal?

You like this, don't you?
There’s a whole field called evolutionary aesthetics, which basically looks into inherited traits that have an effect on the psychological perception other members of a species have of an individual. Why are our lips red? Why do we hate the sight of poop? Why do babies show preference to circles over squares? Why do our brains tend towards things colored with vivid blues and greens?

Since evolutionary aesthetics deals with psychological perceptions throughout the development of a species, over hundreds of thousands of years, it must take into account the changing social environments that affect those psychological perceptions. You see, the perceptions of these traits are not static. For instance, it has been found that men show more preference for larger women when they are hungry. Come back after lunch break, and those same men show subtle preference for smaller women. Should the world fall apart and sink into famine, Vogue will be out of business. Larger women with more resource acquisition abilities will be the hot new things.

I love the elegant tango that happens between natural selection and psychological perception. It’s created the human shape we have now. And the human body may be one of the most inspiring forms, with all of its of curves and colors and lines and fluidity, that our species has recognized yet.

Even if there’s a little bit of it hanging over my jeans right now. The gentle sag of fat over one’s Abercrombie skinny jeans can be inspiring, right?

Oh my god I’m going running right now.

Saturday, June 7, 2014

milk pee

Since I was little, one bodily process has weirded me out more than all the others.

How is it that you can drink a big glass of milk, go pee half an hour later, and it be clear? What happens to that milk for it to turn from opaque white to clear, and in such a short period of time?

As a kid, I imagined a sort of sieve, like the really fine sifter my mom would use for powdered sugar on cookies. In my mind, I could see it at the bottom of the stomach, filtering out all the tiny molecules that made milk white. What was left must have been clear, likely water, and came out as pee. That was one efficient sifter, I thought.

As I went through my biology classes in high school and college, I got a better idea of this magic milk transformation. Your stomach digests foods physically and chemically. Maybe some of the acids helped to break down the milk, I thought. I learned that the kidneys are really the ones responsible for taking stuff out of fluids and producing urine. So it wasn’t my mom’s powdered sugar sifter after all.

I didn’t really get a good grasp on the process until I took Animal Physiology later on in college. Dr. Henry, reputed at Auburn as one of the toughest professors in the College of Science and Mathematics with the highest failure rate, went into detail about the human body to an extent I never expected to delve. We talked about how nerves work, how hormones work, how electricity in the body works, and all of the chemical processes behind these things. I had some gray hairs and no social life by the end of the semester, but I made it out with a B. Almost more satisfying than that B was the understanding Dr. Henry gave me about how the heck our bodies turn milk clear.

Let’s follow milk’s journey through the human body.

1. Stomach
First off, milk is broken down by an enzyme released in the stomach. Lactase gets in there and breaks up the milk party, turning the milk into basic components like sugars, salts, fats, and water. People who are unable to manufacture this enzyme in adequate amounts or at all, are lactose-intolerant.

2. Bloodstream
Parts of your digestive system are connected to your liver by what’s called the hepatic portal system. The remnants of that milk you just drank are now floating around in your bloodstream, being fed through your liver, and throughout the blood highway system of your body. To your brain, to your pinky toe, to your eyes, you name it.

3. Kidney
A nephron and its
regions. We'll get into this
in another post.
Your blood is run through another filtration organ- the kidneys. Our kidneys, in a way, are sifters. Though, they are chemically-driven sifters, rather than physical ones that let things through based on size.

A nephron is a single unit in the kidney. We have a about a million in each kidney, and they’re constantly running blood through and using concentration gradients to pull out unwanted molecules and retain necessary ones. And a nephron is no simple little tube for diffusion. A nephron is a complex thing, with and functional structures and parts that are named after people. The details of how a nephron works warrant a completely new blog post, so we’ll save those for later.

Long story short, the nephron takes what you need from the blood- like say, the calcium from that milk- and gets rid of the rest in the form of urine.

4. Peeville
Urine drains from your kidneys through tubes called ureters to your bladder. Here, the unneeded milk components (water likely being a major component) sit and wait until you get up and go pee. The rest is history.

I dare you to go chug a big glass of milk and see how long it takes for you to have to go pee. If it’s like me, it’s a matter of minutes. The fact that our bodies can do all this in half an hour or less is crazy to me, and even cooler than the powdered sugar sifter in the stomach hypothesis.

It’s also a tangible reminder of how quickly and efficiently our bodies absorb what we put into them- good and bad.

Just some things to think about.

Monday, May 12, 2014

limited options

At about 3:45 this morning, I was scared stiff lying in my bed, staring at my bedside table trying to figure out if I could better kill someone with my 1 oz jar of eye wrinkle cream, lip balm, or my eyeglasses. My option were limited.

Let me explain.

The past few days have been gorgeous here. So last night, I figured I would open my windows to sleep. That, combined with the fact that I washed my sheets with my new Snuggle Scent Booster Pods yesterday, meant that I slept like a rock last night. That is, until 3:45 AM, when I awoke to the distinct sound of someone heavily breathing in close proximity.

My eyes flew open and I froze. I heard a raspy, breathy sound coming from what sounded like my living area like a metronome. It was at this point that I began trying to figure out how I was going to kill/maim this intruder, who had obviously broken in and was sleeping on my couch.

After taking stock of my nearest weapons- eye cream, lip balm, and glasses- I decided hand-to-hand combat was my best bet. I gathered the courage to quietly creep out of bed and peer around the corner- to find an empty apartment. Whewph. But wait, I still heard breathing…

I followed my ears over to my open window to hear a symphony of birds filling the valley as sunlight began to lighten the black sky. The rhythmic wheezy sound was amongst the chorus. It was a just a bird, not an intruder.

I can’t explain what audio-phenomenon was making this bird sound like a person snoring in my apartment, but I wasn’t too concerned about it as I stood at my window, overwhelmed by the birds singing at daybreak this morning. I've heard birds singing at the buttcrack of dawn many times before (re: last summer), but I’ve never heard anything like this morning. It was almost deafening. It sounded like Jurassic Park outside my window.

In songbirds, there is a distinct biological purpose for dawn chorus, as it’s called. It’s almost entirely males calling, either defending territory or trying to impress the ladies. Female birds aren’t sleeping through it, though. They’re paying close attention to which males are up earliest and singing loudest- both signals of fitness that tell the female how studly her sexual options are. I mean, if a guy stood outside my window at 4 in the morning and sang as loud as he could, I’d go on a date with him.

Dawn chorus is actually a thing- in fact, the first Sunday in May is designated as International Dawn Chorus Day, as spring sets in and birds are getting frisky. Bird nerds (I say that lovingly, as I am one myself) have even figured out the order in which different species begin to sing during dawn chorus. This morning, I could hear American Robins, Varied Thrush, Steller’s Jays, and maybe even some woodpeckers. I know there were way more species, but I’m not an accomplished enough bird nerd to tell you what else was singing, and certainly not in what order. If anyone knows what creeper stalker bird sounded like it was breathing in my apartment, feel free to share.

I often write about what morphologies and physical characteristics function is sexual selection, but behaviors can be just as interesting. Like singing your little butt off with BOTH of your voiceboxes (songbirds have two so they can sing more complex and therefore sexy songs) balls early in the morning. Birds put a lot of emphasis on their appearance and their songs in their reproductive strategies. Males with the brightest feathers and the loudest, most impressive song get the ladies. Not all that different from humans, really.

Well. You know where I was trying to go with that.

Sunday, March 16, 2014

tiny robbers with tiny hands

Since moving to Alaska, I’ve come to miss a lot of things that I used to take for granted. Being able to dress cute year round, ceiling fans, iced tea, and summer gardens that grow things other than winter vegetables, to name a few.

One surprising element from home that I miss: raccoons. Those little critters are cute. They are curious, have tiny hands with opposable thumbs, and sport little burglar masks. I miss seeing them.

Why do they have those markings that look like masks? It’s easy to understand why a butterfly might have a big eye on its wings- to deter predators by looking like one. Or why some owls’ feathers look like bark- to camouflage themselves while hunting and while being hunted. But a burglar mask? What good would that do a raccoon?

As usual, the answer is multifaceted. Some folks propose that the black masks helps to reduce glare while these animals are out and about looking for food. Some say that it helps to break up otherwise monochromatic fur to aid in camouflage. But my favorite explanation is the conspecific identification idea.

For a long time, biologists thought that raccoons were solitary- living on their own and not in social groups. But come to find out, related females often occupy territory together, and groups of males tend to stick together to fend against foreign interlopers looking for mating rights. So, they likely need some sort of identification system to keep track of who’s who in their social groups.

I know this mask makes me look good. (wikicommons)
It has been suggested that they use mask markings as a way of identifying each other. Sally the Raccoon might have a slightly broader mask than Nancy the Raccoon, who knows that Roger the Raccoon’s mask flares a little more on the left than it does on the right. Like humans come to recognize each other by facial and body features, raccoons likely use slight differences in masks to know one from the other.

It's neat to think that animals- not just humans- have evolved ways to display individuality as per the demand of social structure. Especially when it's as adorable as tiny robber masks.

Friday, February 14, 2014

Valentine's boom boom (get your mind out of the gutter)

I broke my pants.
Happy Valentines Day, folks!

To mark the occasion, I wore my red hot pants today. They’re a little… tight. So tight that as I held the belt loops and squirmed into them this morning, the belt loop broke right off the pants. Uh well- girl’s gotta do what a girl’s gotta do.

Little hearts littered my inbox and Facebook page this morning. Why is it that the heart is a symbol of love? It bears little resemblance to the organ, which is in function but a muscle, void of any emotional capacity or storage. Seeing as it’s Valentine’s Day, this is a great opportunity to explore where your heart gets its mojo.

The heart beats to it’s own drum, quite literally. Your heart has its very own power supply and time-keeper. That is to say it does not receive signals from the brain telling it to beat. This was surprising to me when I first learned of the heart’s independence, since other autonomic functions- like breathing and digestion- are all orchestrated by signals from the brain.

The heart has two electrical nodes- little groups of specialized cells that initiate and manage your heart’s contractions. The sinoatrial node, located towards the top of the heart, is the big daddy. It initiates the heart beat. If the SA node sparks 60 times a minute, then your heart beats 60 times a minute. Ah lah, your pulse!

The second node, called the atrioventricular node, is located a little farther down than the SA node, to which it is directly wired. The purpose of having this second node is to set up somewhat of a delay system- the AV node contracts the bottom half of the heart about a tenth of a second after the SA node activates. As a result, the cells of the top half of the heart (atria) contract slightly before the bottom half of the heart (ventricles.) This creates more of a wringing motion, rather than the entire heart contracting in on itself at once. That wouldn’t move blood very effectively. But the heart contracting top-down certainly does.

After all, when you listen to someone’s heart you don’t hear “boom… boom…. boom.” Instead, you hear “boom boom…. boom boom….. boom boom.” You’re hearing your atria contract, followed shortly by your ventricles.

So, if you have a honey, I dare you to make your move tonight by asking to “listen to his or her sinoatrial node activate approximately 0.1 seconds before the atrioventricular node.” It will be romantic and s-e-x-y.

What would you do without me to up your Valentine’s Day game?

Bonus question: Which node do artificial pacemakers mimic?

Saturday, February 8, 2014

more than just a pretty face

A few years ago, I went to the Georgia Aquarium for my 22nd birthday. I saw some Spider Crabs straight out of a Steven King novel, a pair of Beluga Whales I secretly wanted to set free, some crazy little seahorsies, and Lion Fish. It was difficult to get good pictures through the thick glass, but the Lion Fish pictures turned out well.

These predatory creatures have creamy white scales streaked by bronze and caramel stripes that decorate their fins and eyes as well. They are attention-grabbing; spikes and stark patterns often suggest that there’s more than just a pretty face at work.

These fish are highly venomous. Their dorsal fins have pokey spines that stick out the top. Inside each spine is a reserve of venom that leaks into any tissue the spine may puncture. Divers that get stuck by these guys experience a host of symptoms that include general pain, local paralysis, breathing suppression, dizziness, vomiting, fever, diarrhea. People rarely die from stings, but children and people with certain allergies certainly can die.

So why am I telling you about Lion Fish? Well, they are wreaking havoc on our Eastern seaboard. Lion Fish are native to the Pacific, but thanks to careless humans, they are now present in the Atlantic. They first appeared in the late eighties, early nineties. Some think that maybe the six captive Lion Fish kept that escaped during the destruction of a Florida aquarium during Hurricane Andrew established the invasive population. Others hypothesize that bored and irresponsible exotic pet owners released their Lion Fish into Atlantic waters.

Regardless of how it happened, they are swimming rampant now. They have no natural predators in the Atlantic, and even potential predators take one look at those spikes and are all “HELL no.” They’re gobbling up native species of fish to the point of threatening their survival. I saw a deal on TV recently with Jeff Corwin where they took a manned submersible down to past 400 feet, where they found Lion Fish. That’s ridiculous- no one thought they’d inhabit depths past 200 feet.

When they encountered the bad boy hunting on a reef at 400+ feet, they speared him and put him in a net to take back to the lab. I imagined children all across the country simultaneously gasping at Jeff Corwin participating in the killing such an impressive animal. But he explained it well, noting that it’s not the Lion Fish’s fault, and it is not a “bad” animal. But it doesn’t belong. As guardians of the Lion Fish and every other species of animal on earth, it’s our job to manage them.

They hauled the Lion Fish up to the surface and cut it open. They found six different species of fish in its stomach- valuable information that can help us figure out how to save our Atlantic ecosystem.

It’s easy to form an emotional dislike, almost hatred, of invasive species. But it’s not like they’re little mustache-twirling villains out to destroy the world. They’re animals, and they’re doing what they know to do. Good practice biology tells us to marvel at all life, even invasive Lion Fish. With the big picture in mind, managing and exterminating populations is part of our role as their protectors.

Wednesday, February 5, 2014

Ham and Nye: Pennies for my thoughts?

The debate between Nye and Ham last night was enjoyable to watch. Both men were gentlemanly and represented their respective world views well.

Of course, as most conversations between science and creationism do, this one hit a wall when Bill Nye asked Ham “What evidence do you have for that?” and Ham replied with a bible verse.

Not all Christians are so literal in their interpretation of the bible. Billions of people value the bible and regard it as holy, but, like Captain Barbossa, see its words more as “guidelines than rules.” This, I dig. Reconciling one’s core religious beliefs with what he or she sees with his or her own eyes. There is still an element of belief required, but it fits with observable fact. It’s quite lovely.

This bible business is the very root of the disagreement. Creationists believe the bible is infallible, that it is inspired by God, that it cannot be questioned, and foremost, that it is true. That every word of it is true, as it is written. Black and white, no questions asked. It says there was a flood 4,000 years ago? Then there was a flood 4,000 years ago. Disagree and you go to hell.

For these people, evolution challenges their very essence. Their most precious beliefs, beliefs that they would die for, are in their view threatened by what science is finding. So scientists, remember to have compassion for these people. Don’t be jerks, don’t assume they are stupid. Don’t say they have no place in science. There are lots of brilliant minds out there who feel overwhelming pressure to not deviate from the words of the bible, and while they should stay away from evolutionary studies, they are still valuable to progress. Open-mindedness, folks. It’s what’s missing from the creation movement, and will also be the remedy.

Let’s stand firm by our science and keep spreading its marvels, but be patient with those who resist it.

Their views will no doubt evolve; it’s only natural.