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?

more than just a pretty face

A few years ago, I went to the Georgia Aquarium for my 22^nd 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.

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.

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.

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.

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

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