Category Archives: Our bodies

Does size really matter? What’s so special about our brains?

Closing out an evolutionary trifecta for May.  Our ramshackle remodeling has brought us a big, beautiful brain, but is it really the size that gives us our smarts?  If overall mass were all that mattered, you’d have to open an underwater chapter of MENSA, as the sperm whale’s brain swells past all others at nearly 20 pounds.  Ours, by comparison, is only about 3 pounds.  It should be obvious, though, that absolute size can’t be the dominant indicator, as a lot of that real estate is needed just to communicate with a body that big.

That’s why a better rule is the ratio of brain size to body size.  We start to sit a lot prettier from that viewpoint, as primates boast brains 5 to 10 times larger than the “average” animal proportion.  Then again, a person’s brain size to body size ratio is just about the same as that of a mouse.  Birds and ants actually come out ahead of us.  There must be something else yet still at play.

 Is it how the organ is organized?  A March study from Jeroen Smaers and Christophe Soligo of the University College of London seems to show, through analysis of 17 primate species that span 40 million years of evolutionary history, that we really started to take off with an accelerated growth of a specific region of the brain, namely the prefrontal cortex.  The prefrontal cortex, part of the frontal lobe, is accepted to be where our thoughtful “executive functions” take place.  In other words, the bit that makes us human.

Three pounds of goo that makes you you.  From scientificamerican.com

Hold on a second, say Robert Barton and Chris Vendetti in an even more recent study!  With their data they counter that, contrary to popular wisdom, the size of our frontal lobes isn’t any bigger than what you’d expect for our bodies.  They argue that previous investigations didn’t tackle the “scaling” issue properly.  Instead, the pair propose we take a closer look at our heightened connectivity between different brain areas.

WHAT DOES THIS MEAN?

What was once “common sense,” that a big brain makes for a brighter being, hasn’t been taken seriously for a while, and even the ideas that supplanted it, like size ratios and organizational complexity, have come under criticism.  We’re not lacking for new ideas on the subject, as British researchers Seth Grant and Richard Emes once presented yet another alternative hypothesis, that it’s the number of different protein interactions in our synapses that set us apart from the rest.

It goes to show just how knotty the study of intelligence can be.  What seems obvious isn’t always true and each successive assertion needs to scrutinized by the community.  New ideas are always cropping up and should be considered.  Our thoughts have gotten us far, but how we got them is still not completely certain.

Forget the swallows. Why couldn’t evolution build US a better body?

I write about evolution a lot here, and there’s a good reason for that.  As Russian geneticist Theodosius Dobzhansky famously opined, nothing in biology makes sense without it.  But that doesn’t mean evolution itself makes sense.  It’s kind of a constant jury-rigging around a basic shape to adapt for ever-changing environmental conditions, whereas a lot of modern organisms would probably function a lot better if they were re-designed from the ground up.  Imagine throwing some snow chains and a plow on a Corvette and driving it through Alaska instead of just buying a goddamn truck like you ought to.  That’s pretty much how we got the bodies we have.  And subsequently why we hurt so much.

I’m talking about major morphological changes, not the shortening of a cliff swallow’s wingspan to better avoid speeding vehicles.  Evolution’s tinkering has taken us from lowly bacteria to the simplest swimming vertebrates and finally to the omni-talented bad-asses we are today (right?), but all that has come at a cost, which is most popularly documented in biologist Neil Shubin’s book, Your Inner Fish.  Besides humorous descriptions of how hernias form due to the weakness created in the abdominal wall by descending testicles (our ancestors didn’t have the temperature-finicky sperm that we do, so their gonads were safe within their bodies, while ours have to make the trek outside during development), he also offers a personal account of what a tragic junkyard the human knee is.  Our frequent knee problems are one symptom of a wonderful yet destructive innovation.

There are at least 12 competing hypotheses as to why man picked his knuckles up off the ground and decided to walk upright, but some advantages are tangible, such as raising the head for a greater field of vision and the freeing of the hands for other purposes, like using tools.  You can feel the negative consequences, too.  Besides knees, our ankles also tend to fall apart, but the worst disaster area is the human back.  The curves in our spines’ S-shape concentrate stress and can lead to scoliosis and spontaneously ruptured discs, a malady more or less unique to humans.  Taking a seat won’t eliminate the problem, either; it just shifts the stress concentration to the lower back.

Who thought THAT was a good idea?  From www.cedars-sinai.edu

Everyone knows we get obese because the tasty (and calorie-packed) treats we crave were harder to come by before we invented vending machines and McDonald’s, but even supposedly healthy stuff can harm our undeveloped constitutions.  While a staple in our current diets, we didn’t really start to eat wheat until the advent of agriculture, and we aren’t equipped with the proper enzymes to break down the gluten in today’s strains.  As much as 70% of humanity is lactose intolerant, as the practice of drinking milk really only became popular in Europe a couple thousand years ago.  Even tooth decay is a relatively recent blight, as the specific Streptococcus bacteria at the source may have jumped to our mouths from the rats that settled down with us in towns.

And there have been trade-offs for that big, beautiful brain of ours, the most noticeable of which is a woman’s wider pelvis, needed to push that mighty melon through.  Even then, babies are still faily helpless, and that protracted maturation period requires a huge amount of caretaking time from the parents.  A deal made within the brain itself was trading a better sense of smell for our increased color vision, as studies seem to show that we wouldn’t have been able to cram both into our craniums.  Frighteningly, the ability to bring all those brain cells into existence may also be what allows us to get cancer so frequently, as other animals don’t suffer it as often as we do.  People don’t undergo apoptosis (the process of killing malfunctioning cells, often heading off the rise of tumors) as much, which is great to allow the brain to burgeon, but not so good when something goes wrong and grows out of control.

WHAT DOES THIS MEAN?

Human beings are built as if you put a modern day, computerized automobile processing system into a Model T.  Great innovation, great performance in some areas, but not nearly as functional as if you just scrapped the old standard and designed a better frame altogether.  Our extended lifespans only further illuminate how cobbled together our bodies are, as the original engine really wasn’t meant to take us past 40.  Shit starts to break down, and we didn’t pony up for the extended warranty.  Too bad we’re stuck with what we’ve got and can’t just take the brand new ’14 Sapiens out for a spin.

What’s the Big Deal About Genetically Modified Organisms (GMO)?

It’s a topic that continues to make headlines and draw visceral reactions.  California’s much discussed Prop 37, a measure meant to require retailers and food companies to label products made with genetically modified ingredients, was dealt a high profile defeat in November of last year.  Similar legislation has failed to pass in other states, though Oregon currently bans the production and import of genetically modified salmon.  Why the concern?  While GMO companies like Monsanto have undeniably done some shady business dealings, does that affect the safety of the products or the production methods?  Are the doubts rooted in science or sentiment?

The first commercially sold genetically modified food, a tomato that takes longer to ripen after picking, hit the market in 1994.  A year later, several food products that were resistant to herbicides or disease joined them.  In the year 2000, scientists were able to increase the nutritional content of a food for the first time, with the creation of golden rice, although its production has been (unnecessarily?) delayed until just now.  Overall though, the practice has been hugely successful, as about 85% of American corn and as much as 91% of soybeans are derived from genetically modified crops.  In fact, the Grocery Manufacturing Association estimates that 70% of items in American food stores contain genetically modified organisms. Betcha didn’t even know.

But really, if you get right down to it, our food crops have been genetically modified since Roman times, and more scientifically since the 1700′s.  The process of selective breeding, through which particular animal and plant individuals are bred to emphasize specific traits, is so ubiquitous that many of our most important crops, including wheat, rice and corn, wouldn’t exist in their current forms without it.  Not to mention broccoli, cauliflower, bananas, ad infinitum.  We’ve been deliberately altering the course of animal and plant evolution for centuries, but few people bat an eye when it’s done in a field.  Why the outcry when it’s done in a lab?

manipulateWell that’s not deliberately manipulative and meant to elicit negative emotions at all, is it?  Image with an agenda from nutritiondenver.com

The answer may lie in the language of GMO opponents, who often refer to the products as “Frankenstein food.”  Marry Shelley wrote her famous tome in 1818, an early example of the European Romantic era, a time characterized by reactionary thought against the Industrial Revolution and the increasing rationalization of nature.  Many balked at recent scientific advances, thinking that man had decided to play God, a theme no more evident than in the novel where a modern Prometheus creates his own man.  Of course science and progress has continued since then, and such concerns almost seem silly in hindsight.  How will our GMO mania appear to our descendants in two hundred years?

WHAT DOES THIS MEAN?

We shouldn’t let knee-jerk reactions and queasy feelings dictate progress and public policy.  There are certainly issues with genetically modified crops that need to be monitored, such as the possible hastening of antibiotic resistance and the introduction of allergens to other foods, but that’s why better regulation and testing from the Food and Drug Administration is needed, rather than labels meant to scare people away from already approved products.

It also goes to show that the American right wing doesn’t hold a monopoly on anti-science ideas, as Chris Mooney and others have suggested.  Unfounded objections from Greenpeace and similar organizations illuminate that U.S. liberals can be just as hard-headed and fact-evasive in certain situations.  See also the opposition to nuclear power.

The Morning After St. Patrick’s Day: Am I Gonna Die or Am I Stronger than Ever?

patty drink

Holy shit, what time is it, man?  St. Paddy’s was awesome, but I’ve gotta get to work.  And I’m still wasted!  FUCK!  Quick, get me some of those enzyme nanocomplex pills developed by UCLA researchers that have been shown to lower blood alcohol content and reduce liver damage.  What?  It’s only ever been tested on mice and isn’t yet available for human use?  SHIT!  Well, at least Mickey D’s should help with the hangover.  Stop laughing!  The cysteine in the egg of my “McMuffin” breaks down acetaldehyde, the toxic byproduct of alcohol metabolism that can cause headaches and vomiting, and the fructose in the OJ will help replenish the sugars I pissed out, mitigating fatigue and loss of coordination.  And if I can score some fries, I’ll get back some sodium and potassium, electrolytes needed for nerve and muscle function.

I feel like hell, but at least I can rest assured that alcohol doesn’t actually kill brain cells.  In fact, there may be surprising health benefits from alcohol consumption!  Small amounts of ethanol itself extended the lives of nematodes from 15 days to 40 days in a recent UCLA study.  Yeah, I guess it must be an awesome party school.  Alcohol can also reduce your risk of developing heart disease, by up to 25%!  And all the soluble fiber in that Guinness we drank will help lower our LDL cholesterol.  The hops can slow the release of bone calcium, limiting kidney stones.

Maybe we should switch to wine, though.  The resveratrol from the grapes may further extend lifespan.  There are also hundreds of reports that it may protect against cancer, dementia and Alzheimer’s disease.  Even hearing loss!  And wine’s purported ability to stave off colon cancer is a nice boost after the fast food, amirite?!

WHAT DOES THIS MEAN?

Shit, we should start drinking more.  No?  Whaddya mean, the hazards outweigh the benefits if you have more than two drinks per day?  And that while alcohol doesn’t kill brain cells, binge drinking may decrease the production of new neurons in the hippocampus by up to 40%?  Wait, almost no human, clinical trials of resveratrol have been conducted?  If the implications of the animal studies hold for people, we’d have to drink upwards of a thousand bottles of wine a day to receive those benefits?  You’re a fucking buzzkill, ya know that?  I’m drinking alone next weekend.

I know that bananas would be better than the french fries!  JESUS!

Mighty Marvels of Regeneration: Could We Heal Like Comic Book Characters?

The best science fiction and fantasy is rooted in reality.  Arthur C. Clarke’s classic 2001:  A Space Odyssey showed what could happen if our current computers developed human-like intelligence and emotion.  Michael Crichton’s Jurassic Park captured the imaginations of kids and the young-at-heart with a seemingly plausible parable on how to resurrect long-extinct dinosaurs (look for a post on this possibility in the future).  And as in Marvel’s Fantastic Four comics, the universe’s planets are often threatened with consumption by a peckish giant in a purple skirt.

Okay, maybe scratch that last one, but what about some of the superhuman feats of our more grounded champions?  Comic characters get beat up a lot, yet they always seem to come back for more merely a month later.  While a healthy suspension of disbelief is required to account for most of that, some of our favorites have built-in mechanisms to explain their near-miraculous recoveries.  How realistic are these regenerative capabilities?  Might they even translate to human applications?

The world famous Wolverine, star of the breakthrough X-Men movies as well as his own solo venture (with a sequel on the way), is the king of stitching himself back together.  His mutant healing factor rapidly regrows enormous amounts of tissue, at one point in his serial even regenerating an entire body around his metallic skeleton after the explosive villain Nitro seared away his flesh.  After his amazing ability was supercharged, he was even able to bring himself back from a single drop of blood!

wolverine skeletoncover image of Wolverine (Volume 3) #48

Such stunts will never be within our grasp, but the concept itself is not unheard of.  Planarians, commonly called “flatworms,” are simple critters less than an inch long that typically live in ponds and rivers.  They themselves are famous for coming back from extreme situations, spawning multiple complete organisms when cut into pieces.  In one mind-blowing study, a planarian was irradiated so that none of its cells could reproduce and it would slowly die.  A single, solitary c-Neoblast (an undifferentiated unit akin to stem cells) was transplanted from a donor into the victim’s tail, and subsequently grew all the former tissues back to create a new, functional animal!  Too bad people are not planarians.

Sure, coming back from a single cell or a little bit of blood is literally incredible.  How about something simpler?  Like, I don’t know, decapitation?  Wolverine’s final foe in the X-Men:Origins film was the regeneratin’ degenerate known as Deadpool, a product of the same super secret government program and perhaps the only dude bad enough to rival our hero in the healing department.  The creep’s head was shown to still be conscious after being removed from his body, a fate the comic book counterpart has suffered on numerous occasions, proving it to be little more than a minor inconvenience.

deadhead

The many-headed, mythologic Hydra would regrow two heads for every one lopped off, and the tiny creature for which it’s named is not far behind.  Composed of a basal disc used to adhere, a tubular body and a mouth opening surrounded by thin tentacles, the bitty beast will actually regrow its “head” when lost, thanks to constant mitosis (cell reproduction) in the body.  If a hydra is chopped up in a blender (who came up with that experiment?), a centrifuge can be used to reaggregate it and bring it back to life, much like Deadpool returned from being smashed to bits by the sinister Iceman in “Uncanny X-Force #16″.  I wouldn’t try this one at home.

All right, all right, no one’s expecting that we’ll ever be able to regrow a head or our entire musculature, but something like limb regeneration seems just feasible enough.  So much so that Dr. Curt Connors, an ordinary scientist, tried to restore his departed right arm with a serum inspired by reptilian recuperative tactics.  The treatment succeeded, but side effects included skin irritation, spontaneous tail appearance and a beatdown from the Amazing Spider-Man.

the-amazing-spiderman-movie-lizard-poster

Similar to a scene in the cinematic adaptation of 2012, there are lizards called skinks whose tails snap off when grabbed by predators, allowing the animal to escape.  Amphibians are better known for regrowing limbs, but the potential for human use recently took a less optimistic turn.  It has long been thought that such recuperation was a skill developed early in evolution, and that the ability had been “switched off” in mammals and birds.  New studies of the red-spotted newt, however, show that many of the newt’s RNA transcripts that code for proteins used in the process are unique to the organism, i.e. not found in other things like us.  That innate ability may just not be there for people, and no magic potion is likely to instill it.

WHAT DOES THIS MEAN?

You should take any story of human regeneration with a grain of salt.  In 2008, hobby store owner Lee Spievack claimed to regrow a lost fingertip by applying a powder derived from pig bladders, an assertion called “junk science” by University of Leeds professor Simon Kay, adding that, “If you could regenerate body parts like this, your first port of call would be a serious science journal like Nature because it would be a Nobel prize winning revolution.”  A similar if not as spectacular story was reported by Californian Deepa Kulkarni, but closer examination suggests it was the proper dressing of the wound to prevent the growth of scar tissue that restored the finger’s appearance, and not a sprinkling of “pixie dust.”

But perhaps the cause is not completely lost.  African spiny mice were found in 2012 to have brittle skin that tears off when attacked; skin they can regenerate complete with hair follicles and sweat glands.  The regrowth begins from a clump of cells comparable to the blastemas employed by salamanders.  People aren’t mice, either, but at least mice are closer cousins than a minuscule, glorified gut tube.  The precedent is now there in mammal physiology, so that one day we may learn how to become superhuman.  Ya know, like a lizard.

Why Your Antibiotics Don’t Work

Did you get hit with the flu this season?    If so, you had plenty of company, as the Centers for Disease Control and Prevention (CDC) peg this year’s United States outbreak as the most widespread since the H1N1 pandemic in 2009.  That’s partially because this season’s flu vaccine seemed less effective at preventing the disease than usual, giving most inoculated individuals only a 56% lower chance of needing further treatment, while benefiting an even more dismal 27% of those aged 65 and older.  It’s somewhat unknown at the moment why the vaccine couldn’t find its stride, but we have a much better understanding of why diseases like strep throat and Staph infections become more and more difficult to combat over time.  And you might be part of the problem.

If you were unfortunate enough to come down with a bad case of influenza, did your doctor prescribe a little bit of Cipro or Amoxil?  He shouldn’t have.  Such antibiotic remedies are only useful against bacterial infections and can’t do a thing to strike at cold and flu viruses.  Why do they get wrongfully doled out?  Some doctors do so to ward off opportunistic bugs that try to move in while the immune system is weakened.  Others feel the need to give sufferers something, even if it’s not effective.  Many patients don’t understand the limitations and won’t leave until they’ve got a scrip in their hand, or they’ll take their business to a doctor who will do what they want, even if that’s in opposition to what they really need.  The CDC estimates that almost 60% of all antibiotic prescriptions in the years 2007 and 2008 were incorrectly applied to viral infections, although reports indicate that statistic has been cut by as much as a quarter since.

nextnatureimage courtesy of nextnature.net

So what?  What’s the harm?  Doctors get to feel like they did something helpful, drug companies make a few more bones and patients receive peace of mind, even if it’s illusory.  The problem with over-prescribing antibiotics is a product of the same process that got us these big brains we use to develop them.  Whenever you drop that antibacterial hammer on a population, inevitably there will be some individual organisms that were lucky enough to have a natural resistance to the chosen treatment.  Those are the ones that survive to make more just like them.  The ill-adapted get whacked, the “stronger” survive and multiply and pretty soon you’ve got a new strain of bugs that brushes off your old drugs like a case of dandruff.  That’s selection in action; Darwinian evolution on display.  We wouldn’t be here without it, yet it’s also what drives some of our worst diseases.  Now half of U.S. Staph infections are resistant to our most common antibiotics and a strain of enterobacteriaceae has proven nearly immune to even the toughest remedies, leading to a 40% mortality rate in those infected.

WHAT DOES THIS MEAN?

You shouldn’t press your doctor for antibiotic treatment unless he’s sure it’ll be genuinely helpful.  Conversely, if you’re diagnosed with a viral infection and a physician tries to prescribe you antibiotics anyway, question him if that’s the wisest course of action.  He might just be trying to avoid and argument.  And when you do find yourself on a regimen, be sure to see the entire course through, as ending early can bolster the remaining bacteria, creating a relapse for yourself and a dangerous new adversary for the rest of us.

Study results are mixed as to whether wildly common antibacterial handsoaps contribute to microbial resistance and if they’re actually any more effective than their garden variety counterparts.  It seems that triclosan, the most common active agent in antibacterial soaps, needs to remain on a surface for as long as two minutes to do its job.  Does anyone actually do that?  When you also consider that new research suggests the very same chemical may weaken muscle contraction and alter hormone regulation, it’s probably not the worst idea to just stick to the old standbys instead.

Antibiotics are overused on animals as well.  The Union of Concerned Scientists has estimated that 70% of of the drugs in America are administered to food animals in the absence of any disease, as a means of promoting growth.   After 35 years of trying to pass similar bills, legislation was finally pushed through in 2012 that requires farmers and ranchers to obtain a prescription from a veterinarian to use antibiotics on farm animals, but what if the vets aren’t any more judicious than our clinicians?  Constant vigilance on the part of the entire medical community and the citizenry itself will be required to check the further emergence of resistant strains.