Monday, January 14, 2013

How Big is Big? How small is small?

Great fleas have little fleas upon their backs to bite ’em,
And little fleas have lesser fleas, and so ad infinitum.
And the great fleas themselves, in turn, have greater fleas to go on;
While these again have greater still, and greater still, and so on.

(Augustus De Morgan: A Budget of Paradoxes)

There's so much we don't know, so much we don't understand. Sometimes we are like elephants, trying to understand the mosquitos that bite us. Other times we are the mosquitos, trying to make sense of the enormity of the elephant upon which we have landed.

Think about this: scientists have just discovered the largest structured formation in the universe. A group of quasars; primitive, pulsating centers of potential galaxies that stretch across a space of 3 billion light years. In other words, light emitted from one end of this structure would take three billion years traveling at light speed to reach the opposite end of the structure. It boggles the mind.

At the other end of the size spectrum lies the bacteriophages. A bacteriophage is a virus that attacks bacterial cell. Imagine how small a virus is compared to a single bacteria. You could fit 4000 or so of these phages inside of the width of a human hair. They're incredibly small! So cover your nose and mouth when you cough or sneeze. You're ejecting tens of millions of these suckers each time you do.

The phage virus has a protein capsule head, a tail, and some legs that act like a tripod, allowing it to land/stand on the cell surface. It's a classic, instantly recognizable "bio shape" that sort of looks like a lunar (moon) lander:

Take a look at that sucker! It's a marvel of evolution! A sub-microscopic structure that has evolved for one purpose and one purpose only: to ensure its own survival. To reproduce. The head/capsule (capsid) is like a jiffy-pop popcorn pan. Except there's no popcorn inside of the phage capsid - what's inside? You got it - phage DNA. It's code of viral life. Or semi-life. Or, whatever a virus is, scientists aren't really sure. The phage lands on the bacteria, drills its way through the bacterial cell wall, and then injects its own DNA into the bacterial cell, forcing the bacteria to make copies - millions and millions of copies - of the phage DNA and new viruses.

These viral offspring fill the cell to the bursting point, at which time the cell releases millions of new viruses. It's quite similar to what's going on in many people who are combatting the influenza virus - "the flu" - right now. ("The Flu" - so named because Renaissance Italians believed that those who got sick fell under the influenza (influence) of unhealthy astrological alignments.)

The evolutionary precision of this design is magnificent, and has been known for decades. But something was recently discovered that blew me away. The virus's legs, those tripod-like things, are not merely a way for the virus to stand and attach to the bacteria. Recent electron micrographs reveal that they remain tucked away - folded up into the phage until they're needed. And then, the virus unfolds its "legs" and they do something amazing: they walk. They walk the virus along the surface of the cell looking for a good point of attachment. A suitable entry point for its own DNA.

Scientists have taken a series of electron microphotographs of this process and have recreated the series of events that occurs. Now, watch this CGI recreation of the process below. There's a blue protein capsule, and the yellow legs. And that DNA that has to be injected to infect the cell. The phrase "dynamic conformation" is used. It just means that the legs are capable of changing their shape.



How does this occur? Why does this occur? How does the virus - which obviously doesn't have a brain, or even the neural net of a starfish - "know" how to do this? Is the virus alive? And if the virus is alive, does this mechanism demonstrate a primitive kind of intelligence? Don't laugh - searching for, and locating the proper point of entry seems pretty intelligent to me. Luke Skywalkeer had a heck of a time trying to do it.

What are the lives of animals and plants ultimately about? Survival. Reproduction. Passing on their genetic material to the next generation. Some viruses, the phages, attach to bacterial cells in order to do this. And 90% of all of the cells in the human body, 90% of human mass, is composed of bacteria - not blood, heart, lung, skin etc. So what does that make us? Who, or what are we? Are we merely the containers, the environment, required by a more plentiful yet more primitive form of life? Who is really in charge? Is it humans, with their arsenal of antibiotics and vaccinations? Or is it this unbelievably small form of life that lives within us, benefitting us, yet also holding the potential to become lethal and harm us?

Are we the elephants? Or are we the mosquitos, gazing out at the vastness of the universe of which we are but a small part?

What are your thoughts on this?