September 29, 2009

September 21, 2009

10 Things Everyone Should Know about Biology

  1. You are made of millions of tiny yous.
  2. Bacteria aren't really that scary.
  3. There are more types of life than plants and animals.
  4. Viruses and bacteria are not the same--at all!
  5. Plants are made of air and sun.
  6. Antibiotics should be taken with caution.
  7. There is such a thing as being too sanitary.
  8. Scientists aren't just old men in white lab coats.
  9. Humans don't always know best--actually we almost never do.
  10. There is still a lot we don't know!

September 20, 2009

The Tree of Life

Because we are a little self-centered, people seem to think of "life" as "animals." In fact, animals are a very small group on the Tree of Life.

The Tree of Life is a representation of all the different types of living things on our planet. If you draw a diagram of it, using lines to represent all the different groups of living things, it starts to look, well, a lot like a tree. So someone decided the Tree of Life was a great name for it. Genius, if you ask me.

*This is not drawn to scale. Not at all. It's just a sketch.

The base of the Tree of Life is the first life form. What was it? Where was it? Who was it? This is a whoooooole other topic of discussion. But that is where this tree starts--at this theoretical point.

The Tree of Life has 3 main branches: eubacteria (you-bacteria), archaea (ark-ee-uh), and eukarya (you-carry-uh). A lot of funny-sounding names for the big 3 domains of living things.

Eubacteria
Also known as just plain ol' bacteria. These are small, single-celled creatures with no nucleus.
Archaea
Believe it or not, these guys weren't discovered until recently. If you look at any biology textbook more than a few years old, it won't even mention them. Their discovery forced scientists to redo the Tree of Life. Before then, the Tree of Life had 5 branches--known as the 5 kingdoms: bacteria, protists, fungi, plants, and animals. Archaea messed this all up because they are single-celled prokaryotes (they don't have a nucleus), but they are completely different than bacteria, so they couldn't be put in the same group.
Some scientists said, "Okay, then give them their own kingdom, and we'll have 6 instead of 5." Sounds logical enough, but other scientists argued that just making a new kingdom wouldn't show how wildly different they are from other life forms. So they wanted to create a new grouping above kingdom to show that they are truly off in a corner by themselves. Those are the 3 main branches, or Domains, of the Tree of Life.

I know it sounds strange that bacteria and archaea could both be single-celled and nuclei-free, and yet somehow be wildly different. Here are some differences:
  • Their cell membranes are made completely differently.
  • They "eat" and "breathe" completely different things.
  • Archaea live in places that scientists long thought were incapable of supporting life, like thermal vents at the bottom of the ocean and boiling acidic hot springs.
So in a nutshell, archaea are very strange, very dramatic microbes. They live in dramatic places and cause drama among scientists.

Eukarya

Eukaryotes (you-carry-oats; sounds like a weird breakfast cereal, right?) are the forms of life we usually think about (and one we don't): protists (yeah, that's the one), fungi, plants, animals.

Kingdom Protista is sometimes called the "junk drawer" kingdom because anything that has a nucleus and doesn't fit anywhere else just gets put in here. Protists range from single-celled guys like paramecia to algea and seaweeds. That's a pretty random group.

Fungi consist of single-celled fungi, like yeast, and multicellular fungi like bread molds and mushrooms, to name a few types. I think most of us forget about fungi until they start eating our food for us. Get off my cheese! I wanted that!

The Plant Kingdom is very familiar to us. We eat them, use them for shade, and write notes on their dead bodies (ew, gross). Plants are multicellular and use the sun for energy, although some of them also eat bugs--like the venus fly trap.

Last but not least, the Animal Kingdom is the kingdom we happily call home. It consists of mobile, multicellular creatures that eat other life forms (poor other life forms).


Again, here is the breakdown of Domains and Kingdoms in a nice little table for you to enjoy:





DomainEubacteriaArchaeaEukarya
Kingdoms



Bacteria



Archaea



Protists
Fungi
Plants
Animals

September 19, 2009

Cells!

Cells, cells, cells. I just love cells. Why? Because I, myself, only exist because the millions of cells in my body are busy taking care of the business that is me. I love those little guys. All of my friends are made of cells too--my human friends as well as my guinea pig and my house plants. (Yes, my house plants are my friends. No, I do not talk to them.)

I'm pretty sure everyone over the age of maybe 10 knows that living things are made of cells. I think it is taught as a mantra. "Living things are made of cells. Living things are made of cells. What are living things made of? Cells." Everyone knows this. But do people really understand this? (There is a difference!)

I do think people understand what it means that living things are made of cells, but no one really thinks about it all that often.

It's hard to believe, though, that not long ago, people didn't know life was made of cells. Before there were microscopes capable of looking at life on a small scale, no one had seen them. Before we knew about cells, living things were viewed as a whole, not the sum of a million moving parts.
Existentialism at its tiniest.

Because no one knew about cells, it was particularly difficult to describe what was happening if the body wasn't working quite right. If you were sick, it was diagnosed as a problem with your "vapors" or "humors" or "elements." The human body was seen as a sum of the elements, Captain Planet style--Wind, Water, Fire, Earth, Heart! (Heart?)

What I like best about cells is that they are tiny little beings. They can live on their own, in some cases, or they can live as a group and make something as small as an ant or as big as a blue whale. They are talented little building blocks that are incredibly versatile. They make very different forms of life, and within a single organism, they come in a wide variety of types.

I have brain cells, skin cells, muscle cells, liver cells--oh goodness, I'm already tired of listing. They all have specific jobs, and they do them without complaint. I should send them a million tiny thank you cards, really. I mean, I have their address.

For a moment, try to feel the millions of cells that are working tirelessly to keep you going through your day. The cells of your heart contracting to a beat; the cells in your intestines, working your peanut butter and jelly sandwich through your body; the blood cells rushing through your vessels; the brain cells sparking and talking to one another. You are a very complex pile of cells! Doesn't it feel great?

September 11, 2009

Allergies

Allergies are annoying. I think we all agree about that.

Allergies are the body's overreaction to harmless foreign substances. Your body has an immune system that is based on telling the difference between you and everything that is not you. This is a great system for dealing with invaders such as viruses, bacteria, parasites, toxins, etc. "Hey you, I don't recognize you. Get outta here!"

The body "gets them outta here" by producing extra mucus (runny nose) flushing out the points of entry (watery eyes, sneezing), and possibly swelling areas of entrance to get more blood in the area to eliminate the intruder (such as a swollen bee sting).

In this way, your body is a little bit like a small mountain town where everybody knows everybody. If you lived in this town and one day saw an unfamiliar man, you would know right away that he is an "outsider." But here's the thing--just because someone is an outsider doesn't necessarily mean they are there to terrorize the town, right? But if you have never seen an unfamiliar face in your entire life, odds are you are going to overreact and assume the worst, especially if you feel that the safety of your town is at stake. (Have you seen the first Rambo movie? It's a lot like that... well, sort of.)

This analogy is even better because allergies are strongest in people whose bodies are very sheltered, like our small mountain town. If your body isn't normally exposed to pet hair, dust, and pollen, then when you are exposed to such things, your body will sound all the alarms as if this foreign material is a real threat to your body and health.

And guess what! People who are exposed to these things when their immune systems are young and figuring things out rarely develop allergies to them. Back to the town: if your small mountain town has great outdoor sporting activities, and therefore gets tourists fairly often, the townsfolk won't freak out and put every unfamiliar face in jail for no reason!

Why are allergies so common these days? Again, people whose immune systems aren't exposed to these allergens (friendly tourists) overreact when they are exposed to them later. Why aren't people being exposed to pet hair, dust, and pollen as often? Well, because of our obsession with hygiene, mostly. Most parents don't let their baby play on a dusty floor or around a shaggy dog. Children aren't growing up on farms any more, near lots of different plants (and pollen) and many different kinds of animals. We are becoming increasingly sanitized, and we think raising children in sterilized houses is the best way to keep them healthy. It may not sound right, but letting children play outside and get a little dirty is the best way to avoid their developing allergies. Now, you can get too much of a good thing, so letting babies play in sewer isn't what I'm suggesting here.

Can allergies be dangerous? Yes. If someone is extremely allergic to something, the body's overreaction goes beyond watery eyes and a runny nose to more severe swelling. The skin will get swollen to the point that eyes are swollen shut and possibly the throat as well. If a person dies from an allergic reaction, it means the swelling was so intense, he or she couldn't breathe and suffocated. This kind of reaction is seen with food allergies or allergens that are injected into the bloodstream, such as a bee sting. If you or someone you know is having an intense allergic reaction with swelling and hives, go to the emergency room. An allergy can become life-threatening faster than you might think.

Allergies are a combination of genetic and environmental factors, and they can change throughout your life. Some people develop food allergies in their 20s. Some people had food allergies as children that just went away. Your body's reaction to these invaders can't always be predicted.

If only we could have brunch with our immune system and assure them over their cup of coffee that it's really not necessary to lose their cool every time they see someone they don't know. But your immune system is just being overprotective. If you really think about it, it's kind of sweet.

September 10, 2009

We Are All Scientists

I find it particularly funny when people think scientists are just those that stand around in labcoats mixing colorful liquids in oddly-shaped glass beakers. This isn't true at all! All human beings are scientists. Don't believe me? Well, a scientist is one who deals with the principles of science. Let's see what exactly that is:

Systematic knowledge of the physical or material world gained through observation and experimentation.

After looking at this definition, do you think you're a scientist? Probably not. But let me give you an example of a well-thought out scientific experiment that took place in every day life. I witnessed this first hand:

My little sister was 4, and I was 8. She came to me before she went to bed one night and whispered, "Katie, I lost a tooth today. I think mom might be the Tooth Fairy, so I'm going to put the tooth under my pillow, but I'm not going to tell mom. I'm going to see what happens."

I replied, "That is a great idea. You do that."

My sister went to bed, and I went and told my mom what was up--just doing my part to preserve the innocence of childhood for a bit longer.

Now, this might just sound like usual cute little kid stuff to you, but actually, it is a quite elegant experiment. Without realizing it, my little sister had traced out the basic steps of the scientific process. Her hypothesis was that my mom was the Tooth Fairy. The independent variable was notifying mom of the lost tooth, and the dependent variable was the Tooth Fairy response, a coin under her pillow in the morning.

To test her theory, my sister changed the independent variable--she didn't notify mom. Now, If I hadn't ruined her experiment by telling our mom, she would have discovered with science that there was no Tooth Fairy because the dependent variable would have changed also--the Tooth Fairy wouldn't have done her job. This would have proved that the whole process depended on mother notification, which definitely implies that it is indeed the mother who is performing these "Tooth Fairy" duties.
All human beings are scientists because we are constantly testing our surroundings to find out information. Even infants are scientists: "Will this annoy my mom? No. Will this annoy my mom? No. Will this annoy my mom? Yes. Now I know what to do when I want to annoy my mom in order to get what I want."

Science is not just the Dr. Frankenstein cooped up in a basement lab with bubbling beakers and cadavers. Science is simply the process all humans use to discover new things. Think about all the ways you have learned new things and tested the limits and outcomes of yourself, your friends, and the world around you. You're a great scientist!

Natural Selection

Here is the boring definition:

The process in nature by which only the organisms best adapted to their environment tend to survive and transmit their genetic characteristics in increasing numbers to succeeding generations while those less adapted tend to be eliminated.

Here is the super short definition:

Survival of the fittest.

Here is the still-rather-short-but-a-bit-more-accurate definition:

Survival and reproduction of the fittest.

The basic idea is that nature is a constant struggle to stay alive and reproduce, and not every organism that is born survives long enough to pass on their genes--only the "best" or the "fittest" are able to, which means that the "best" and "fittest" genes are the only ones to get passed on. So over time, a group of organisms becomes more adapted to its unique environment.

It's not very helpful to think about Natural Selection in human terms because we don't have hundreds of kids assuming that only a fraction of them will survive to adulthood. Humans have a different strategy--we have just a few and invest a lot of time and energy into them (note to self: call my mom tonight). We are not the only species with this strategy, but it isn't as common as the other strategy: have hundreds of kids and hope that 1 or 2 make it.

Think about sea turtles. They lay dozens of eggs on a sandy beach, bury them, and take off. The mother doesn't get to see them hatch, run for their lives from hungry sea gulls, and grow to adults. She does what she can in the hopes that maybe 1 of those dozens of eggs has a future as a 100 year-old turtle. And just 1 is probably all it will be.

We humans have separated ourselves from nature in many ways, so we forget that survival is a constant struggle, and one that not every creature wins. To survive and have babies that will inherent one's qualities, a creature must survive it all: disease, injuries, predation, weather, unpredictable food availability, and so on.

Many people misunderstand Natural Selection, thinking that the species can somehow "choose" to adapt to a situation. I think this might stem from the common nature show host saying something like, "and so the gazelle must adapt to its environment or perish!" It really doesn't work this way. A species can no more choose to adapt than you can choose who your parents are. It's really based on chance. Natural Selection can only select traits that are already there.

Another example of this misunderstanding: Kevin Costner's character in Waterworld (did that character even have a name?). He has gills, and the other people are either terrified or intrigued by them, but this implies that he developed gills because humans are living in water now. This makes it seem like there is a cause-effect relationship here: "hmm, now we humans have to deal with water. Let's make us some gills!" Sadly, this is not the way things work. The odds of a human spontaneously being born with gills are the same whether or not the earth is covered in water. And what are those odds? Well, slim to none. Sorry, Kevin.

You heard it here: a changed environment or some new need does not create new traits. Instead, individuals that are better suited for a new situation will survive and reproduce, and the ones that aren't suited... well, they don't survive or they don't reproduce.

So Natural Selection doesn't create new traits, it just selects the "best" of what is available. What, then, does create new traits? How do things adapt, changing slowly over time?

The answer, my dear, is variation, diversity, and just a pinch of randomness. Variation is built into every step of the process that we call "life." Reproduction shuffles genes around, creating different combinations of traits. Random genetic mutations can create new traits, and even certain sequences of DNA can be turned "on" and "off" by a variety of factors.

In summary, you, my friend, are the result of 3.5 billion years of life slowly changing from a single-celled creature to the walking, talking, cell-phone-toting creature that is you. You are alive because not a single one of your ancestors, going back those billions of years, didn't make it. Every single one of them survived long enough to reproduce, passing their genes on to the next generation. None of your predecessors fell off a cliff or was eaten by a bear (before reproducing, that is). You are a shining beacon of hope in the universe, proving that life can and will prevail! Now go shout it from the rooftops! (But, um, don't fall off.)

Organic

What does it mean to be organic? Why is it such a big deal?

For a farm and its products to be "certified organic," they must jump through many, many hoops. They have to fill out tons of paperwork, undergo on-site inspections, and adhere diligently to a list of requirements. The way I like to think of certified organic growers is that they farm like it's 1492. (There is nothing specific about 1492--other than that's when "Columbus sailed the ocean blue." I just mean farming practices of a few hundred to a few thousand years ago.) Organic farmers grow their produce in step with nature, which means it is better for the earth and better for us.

Organic farming is better for the earth because they aren't using any 'cides--herbicides, insecticides, fungicides, etc. The suffix "cide" means "to kill." Non-organic farms may use a variety of chemicals intended to kill weeds, bugs, or fungi that can make the plants sick. Here are the obvious problems with that:
  1. If you spray poison on plants so bugs won't eat them, why would you want to eat them?
  2. If you spread poison on a large area of land, does it stay there? Where does it go?
Answers:
  1. To be honest, I'm not sure why anyone would want to eat something that has been sprayed with deadly chemicals. I sure don't want to.
  2. The poisons sprayed on crops don't just stay there. They are washed away into nearby water sources--creeks, rivers, lakes, and/or oceans. The insecticide that is meant to stop aphids from eating lettuce may wash down a river and kill bugs that are important to an ecosystem. Organic farming is better for the environment because it does not produce deadly runoff that can harm nearby wildlife.
With this information, don't you think that everyone would want to eat organic all the time? Why do people buy produce that isn't organic?

Here is the one and only downside of organic produce--it is more expensive. Money is the only thing I can think of that would make a person reluctant to buy organic.

Let's say you go to the grocery store and see this:

Bananas $0.19

Organic bananas $0.50

"Hm, the organic bananas cost more. If I don't know anything about how great organic farming is, and I don't know that eating organic is better for me, why should I spend more money on it?"

Exactly. And sadly, even if someone knows that organic is a better choice, they might not be able to spend the extra money on higher-quality produce. It is a constant struggle.

I don't have a ton of money sitting in the bank, but I buy organic produce whenever I can. When I spend a few extra dollars on organic fruits and vegetables, I know that my money is going to support the eco-conscious farms that produced them. That makes me feel good, and eating great produce makes me feel even better.

Plastic

Plastics haven't been around for very long--about 50 years. What's scary is that we don't really know what will happen to all the plastics we've produced over long periods of time. What we are starting to realize, though, is that plastics don't really go anywhere.

The problem is that plastics are not what you'd call a "natural" material. That means they haven't been around very long, which also means that there is nothing that will break them down. Think about the other materials people come into contact with on a daily basis. We live in homes made of wood or maybe rocks or metals of some sort (brick, cement). We drive cars made of metal. We write on paper. We use forks made of metal, glasses made of...glass, and plates made of ceramics (basically more metal). Obviously, we also interact with food--plant and animal products.

Where do these things go when we are done with them?

The food we eat is excreted as waste that is broken down by lovely bacteria. The food we throw away is eaten by other takers--fungus, bacteria, insects, etc. Sometimes we throw away food because the fungus starts eating our food before we even got a chance. Moldy bread, anyone? Yum!

The wood of our homes and the paper we write on will eventually biodegrade. A combination of elements and microorganisms will break it down and that material will be recycled naturally. The tree that became the paper will become the soil that supports the next tree. Think of the "Circle of Life" song from the Lion King.

The metals we use (brick, cement, iron, steel, etc.) in every day life don't biodegrade exactly, but they can be broken down and weathered, and they go back to form the sand, the ground, the earth. Not a big problem.

Plastics, on the other hand, don't biodegrade. They don't break down to form anything useful. They just... they just... they just keep being plastic. They don't go anywhere. This is a problem. Nature is all about recycling and reusing. Nothing goes to waste.

Plastics are forever. They don't break down; the material doesn't return to the earth. All plastics seem to do is end up in rivers, lakes, and the ocean. Clogging waterways, choking animals, and generally getting in the way.

Plastics exposed to direct sunlight seem to break down--but the particles aren't changing. It's just breaking into smaller and smaller pieces. What will happen if plastics break into millions of tiny particles instead of one bottle? Think about it this way--what would be easier to control, a glass bottle, or a shattered glass bottle? That seems to be all plastics do, break into smaller pieces. What if they get small enough to get into the blood streams of aquatic animals? Will it be poisonous? Who knows.

After 50 years of finding better ways to produce plastics, and more ways to use them, we need to spend just as much time and energy trying to stop using them.

As common as plastics have become in packaging, electronics, and other products, there are lots of ways to avoid them:

  1. Buy reusable grocery bags, and if you forget them, ask for paper bags, not plastic. We can replant trees, but we can't undo the plastics.
  2. Stop drinking bottled water. Buy a metal canteen and fill it with water every day.
  3. Use tin foil instead of cling wrap.
  4. Be sure to recycle the plastic products you do use.
In general, be mindful of this complicated product. Avoid it when you can, and if you can't, buy less and make sure you recycle it because that bottled water, that shopping bag, that old keyboard--it will sit in a landfill or float in the ocean forever.

"Paper or plastic? No, canvas!"


Photosynthe-what?

Photosynthesis is pretty amazing when you really think about it (what do you mean, you never think about it?). What photosynthesis describes is how this tiny little seed can grow into a plant as big as a tree. How is this possible?

Think about how animals like us grow. A baby grows in a mother's womb from a single cell to an 8-ish pound baby. From then on, how does this tiny person grow to be a 150-pound adult? (These weights are just examples. Not every baby and adult have to weigh these amounts. Don't get hung up on these details.) Where do those other 142 pounds come from? Well, from the food the person eats. Food is energy; food is mass. When a child is growing, the food she eats goes toward her energetic needs--keeping her body temperature up, keeping her muscles moving--and some of it goes towards actual body mass. The atoms you eat (such as carbon, hydrogen, oxygen, nitrogen, etc.) are used to create the mass of your body. That saying, "you are what you eat" isn't just clever, it's true. The carbon atoms in the bread a child eats can become the carbon atoms in the cells of her body. Woah. So that means those 142 pounds come from a combination of bread, cookies, broccoli, spinach (yum!), fries, and chocolate shakes--whatever that person ate growing up. Makes you think a little more about your diet, hm?

Since plants don't eat food, how do they grow? Where does all the "stuff" come from to make a giant tree?

Let's simplify this: life on earth is carbon-based. All life forms need a source of it. We get carbon from the food we eat--carbohydrate, protein, and lipids (fats) all have carbon. Plants get their carbon from a different source--the carbon dioxide (CO2) in the air! That's right! There is a great source of carbon floating around in the air all the time. Every time you exhale, you release more CO2 into the air.

Plants use the energy from the sun to change carbon dioxide in the air and water from its roots into sugars that they can use to build the tree trunk, stem, leaves--whatever!--that make up the plant's body.

This is a very difficult idea for most people to accept. If you give a person a seed and a log and ask him "where did all this mass come from?" he will likely say that it comes from the soil. Maybe you thought that plants grew because they "ate" the soil too. But here is a very easy way to disprove this to yourself: if you plant a seed in a pot, water it, and watch it grow, does the soil start to disappear? No. It stays there. The plant seems to grow from nothing. But what it is actually doing is using air, water, and light to build its own body.

The other hurdle you have to jump to truly understand how this works is the idea that air is nothing. Most people think about air as empty space, but it's not. Air has mass. Air has stuff. If air moves fast enough, it can knock down buildings. Just ask anyone who has been in a tornado or hurricane. Take your hand and fan your face. Feel all that "stuff" hitting your face. There is definitely something there. Not a ton of mass, but mass nonetheless.

So the next time you see a small flower or a big, shady tree, stop for a moment. Look at it and think about how all that mass--that "stuff"--came from something so simple and seemingly empty as air. Wow.

Antibiotics

Now, let me warn you right off the bat: I get a little hostile when it comes to antibiotics and many people's ignorance related to them. If things get a little tense toward the end of this, don't worry. I still love you.

Antibiotics were discovered accidentally when a fungus landed on a petri dish and inhibited the growth of the cultured bacteria. The chemical causing this inhibition lead to the first mass-produced antibiotic. Good, great, fabulous. Lives were saved; people paraded down the streets in joy, adopting kittens, and kissing babies. But then something terrible happened: people took this "miracle drug" for granted, thinking they could pop one and be done with it.

Now, for this common misunderstanding regarding how exactly antibiotics work, I blame doctors. These days, many doctors throw prescriptions around to get needy patients out of their faces without explaining the drug and how it works. Here is what happens:

Oh, I feel so sick. I'm so glad my doctor gave me this orange bottle full of huge pills. Augmentin? What's that? I don't care as long as it makes me feel better.

I started taking these an-ti-bi-o-tics yesterday, and wow, do I feel better! These things are great. I'll take this one with my breakfast.

Oh, man. My stomach isn't feeling so well. I think these pills are upsetting my digestive system. I feel like my sinus infection is gone now, though, so I guess I'll just stop taking them.

This is the usual progression when someone takes antibiotics. This is the worst thing you can do, though, and almost no one understands it. Let me explain what antibiotics do and what happens if you stop taking them.

When you take antibiotics, you usually start by taking 2 pills with a meal, and then take them twice a day from then on (breakfast and dinner). The first wave of antibiotics kills the majority (let's say 75%) of the bacteria causing the infection you have. So people tend to feel better within 24 hours of starting their course, which is great.

The downside of antibiotics is that they are very effective at killing the helpful bacteria inside your body, along with the ones causing problems. The bacteria that live in your gut help your digestive system function, so yes, when you wipe them all out, you'll have an upset stomach. The best way to avoid this side effect is to eat yogurt every day you are taking antibiotics to attempt to replenish the colonies in your digestive tract.

Now, the fact that the infection subsides after a day coupled with the upset stomach side effect dissuades many from continuing their 14-day course of antibiotics. The problem with this is serious--after you've taken antibiotics for a couple days, you've killed the majority of the bacteria, but you still have a few--the strongest few--left. If you abruptly discontinue the antibiotics, you allow these survivors to re-colonize your body, forming a stronger version of the bug you had before. Fabulous.


People who do this wind up back atthe doctor within a few weeks complaining that the antibiotics didn't work and that they are sick again. So what does the doctor do? Why, prescribe a stronger antibiotic, of course!

And the terrible, terrible cycle continues--producing stronger and stronger strains of bacteria. We now have to deal with certain strains of bacteria that are entirely resistant to all known antibiotics. And it is mostly attributed to the misuse and misunderstanding of antibiotics and how they actually work.



These days, people have an obligation to seek to understand their bodies, their health, and technology. And scientists and doctors have to take the time to make it understandable to the rest. This terrible cycle of ignorance and complacency simply won't do.

Your body is a complex machine with billions of interacting cells--some your own, some foreign citizens in your body. Do not take it for granted. This is your body, your health; and the way you use it or abuse it can affect those around you more than you know.

Take those antibiotics until the bottle is empty! No excuses!

Virus? Bacteria?

This is a very common question: what is the difference between viruses and bacteria? These two little guys often are mixed up because they both are quickly dubbed "those things that make us sick." For a full explanation on this with regards to bacteria, see the "Bacteria" article.

To illustrate how not only separate but wildly different these two babies are, remember that bacteria are alive. Yes, they are teeny tiny life forms that live in the ocean and in your nose. Lovely, great, wonderful. Now, viruses... viruses are not technically speaking "alive." That doesn't mean they are dead (because you must at one point be alive to then be dead); it means they are "non-living." When thinking about viruses' being in the same category as other non-living things, like say, rocks--it can be a difficult idea to take a walk with. Non-living things don't seem as though they should have a big effect on our bodies.

Let's stop there a second and think about that though. Let's take a non-living thing like salt. Too little salt (iodized salt) and you can develop an unpleasant illness called goiter. Too much salt can give you diarrhea, make you vomit, even kill you. (If you are even stranded in a dingy in the middle of the ocean, remember that.) Salt is not alive, but it has quite the effect on our bodies.

The obvious difference, of course, is that we can choose how much salt to put in our bodies, but with viruses we get almost no say in the matter. They are opportunists that can enter the body through open wounds, mouths, noses, eyes, etc. This certainly makes them sound alive, if not devious and just plain rude. But they aren't!

Okay, okay, I'll explain. Basically, a living organism has to have the following characteristics:


  1. DNA
  2. The ability to reproduce itself
  3. Responsiveness to its environment


Depending on what you're reading, there may be more, but these are the basics. Now, viruses do have DNA (sometimes RNA), and you could argue that they respond to their environment, but guess what they don't have at all? Ding ding ding! The ability to reproduce themselves! Viruses do not possess the cellular machinery to make more of themselves. All they are is a protein shell with some DNA (or RNA) inside. What makes them so inconsiderate is their use of our innocent cells to do their reproduction bidding. They get inside your cells, hijack your organelles, and produce hundreds of copies of the virus. When they are all done, they destroy the cell completely as they burst out of its membrane looking for more cells to infect in order to reproduce. When you have a virus like the cold or flu, your symptoms are usually caused by cell damage and your body's attempts to get rid of them. Bright green mucous in the nose means it is full of dead cells--they are the casualties of the war going on in the body.

So viruses are not technically alive, but they have been around a very long time. Some scientists theorize that viruses were the precursor to life on earth. If you think about this for a moment, it doesn't quite flow though because viruses can't reproduce without a host cell... and if viruses came first... what host cell did they use to reproduce? Um, I'm sorry, but I don't know either.

There are other theories about viruses that show a friendlier, more helpful side of the little protein bubbles: some scientists think they are a major cause of evolution. Think about it. They are built to inject DNA into other cells. At some point, they could have gone about injecting new genes into other cells in some sort of primordial soup of simple creatures. If the DNA a virus injected made that creature stronger in some way, then hey! that trait would have gotten passed down and helped move evolution along.

Wow, all this time, and I still haven't answered the question of the difference between a virus and a bacterium. Let's discuss their differences as we consider how they can affect our bodies. (I know I said we shouldn't just focus on their negative effects on our bodies, but I can't entirely avoid the issue, can I?)

Think of your body as the city of Tokyo. Don't argue with me; just do it. Okay, now you body is the city, and a bacterial infection could be represented as Godzilla. Godzilla is bumbling around stepping on people (the cells of your city), knocking over buildings, ruining roads--just causing all out havoc... by accident. Godzilla is not evil. He wasn't plotting his assault on Tokyo from the bottom of the Pacific. He's just in the wrong place at the wrong time, and yeah, it's not going well. The upside is that it is pretty easy to tell the difference between members of the city of Tokyo (your body) and the intruder, Godzilla (bacteria). Without too much heartache, bacteria can be removed from the body, and Tokyo can get back to normal. (This, of course, assumes we're not dealing with a strain of antibiotic-resistant bacteria, which you can also read about.)

Viruses, on the other hand, are more like a secret agent with a bag full of grenades. He's walking around, unnoticed, going into buildings and setting off explosions, and disappearing into the crowds. He is causing all kinds of damage, and no one can tell where it's coming from. Because no one can find him, no one can get rid of him. Very different way to affect a city/body (if you can keep hanging on to this metaphor).



So now you know that viruses and bacteria are wildly different albeit tiny things. They both have a dark side (a side we are all too familiar with), but I hope I made it clear that they are not all bad; certainly not worth being angry with. So the next time you find yourself cursing the virus that gave you your cold, remember you might as well direct your anger at a refrigerator magnet--because there is no one at fault or worth blaming. Just drink some tea and be the intelligent vertebrate I hope you are, and let the anger go. The virus can't understand you.

Bacteria

"Don't touch that! It is covered with bacteria!"

Have you ever heard that? Bacteria are probably the most misunderstood living thing in our culture today. We know that they are around, and we're told to avoid them at all cost. But what are they?

Bacteria are very small, single-celled creatures. Bacterial cells do not have a nucleus, so they are considered by some to be "simple" life forms. But if you talk to any microbiologist they will tell you these critters are hardly the basic, uncomplicated, scary life forms we make them out to be. First of all, there are millions of different kinds. We haven't even discovered them all yet! They reproduce in as little as a few minutes, and they can "eat" and "breathe" substances that are toxic to other forms of life.

What very few people understand is that few bacteria are harmful to humans--less than 10%. Those that do cause sickness aren't trying to--they just end up in the wrong place. It isn't even the bacteria themselves that cause the problem; it's usually their waste products, and our bodies' overreaction to them.



For example, the most common sickness due to an overdose of bacteria is food poisoning. If you eat food that is kept too long in conditions that allow bacteria to grow (such as leaving food out on a warm day), you bombard your stomach with a bit more than it bargained for. The waste products that bacteria excrete are irritating to the body, so your body defends itself. If the reaction is particularly strong, you might throw up. As unpleasant as it is to lose one's lunch, those few moments of discomfort might be preferable to the next option: the body's flushing of the toxins out of your body the other way. Yeah, diarrhea. If the body goes this route, it makes the body very dehydrated (since your water stores are being used to wash your intestines). If you go to a doctor with such food poisoning, in most cases, all your doctor will say is "keep hydrating!" And unfortunately, that really is all you can do.

Now, let's get back to the main point here. Not all bacteria give you food poisoning or make you sick (such as the common sinus infection). The vast majority of them don't hurt you at all, and a good number of them actually help you. Yes! They are GOOD bacteria. Why is it that these little guys aren't ever on the news at 5:00? For one thing, they help us digest our food. You have millions of bacteria living inside your intestines right now making you feel good. Have you had yogurt recently? What makes yogurt yogurt is "live, active cultures" of--you guessed it--bacteria! You can even see what strain of bacteria you are eating if you read the side of the container. If you take antibiotics, you might have an upset stomach because the antibiotic kills the harmful bacteria and all the happy nice ones too! They didn't even get a warning, the poor little things.

Bacteria are just about everywhere: all over your skin, in your intestines, on your pen, on your food, in the air. If all bacteria were as scary as we think they are, humans couldn't exist on this planet. A little knowledge goes a long way when confronting a fear. Bacteria aren't all bad. Now, this doesn't mean you should go to the nearest public restroom and lick the floor. No, no, no. I just mean that it's not worth the energy to be afraid of bacteria and spray your entire home with bleach.

So take a look around and imagine you can see all your little bacterial friends hanging out with you in your office or home. They just want to be loved. So show a little compassion, and give bacteria a break.