Thanks Again Worms – You Inspire Me*

Muscle cells come in 3 main varieties – skeletal, smooth and cardiac.  As you might expect skeletal muscles are those that attach to the skeletal system and provide the contractile forces that let us (and other animals) move around. Not all animal locomotion is generated by skeletal muscles. Smooth muscles in worms generate a peristaltic contraction that results in the characteristic worm squirms. Peristaltic contraction is cool to watch. 

The basic principle is that the ring-like muscles squeeze one after another so that the contraction propagates down the length of the worm and it moves forward.  This would be like moving a sausage by squeezing it at one end then sliding your hand down the length of it.  With a sausage you might make a mess as the increase pressure of meaty goodness accumulates against the end of the casing and eventually bursts. 

With peristaltic contraction the action doesn’t work on moving a gooey meaty center but rather works to push the adjacent muscle forward a little bit.  It rained throughout the day today in the Minneapolis area and there are quite a few worms out.  I definitely recommend watching them move, it is pretty awesome. 

Worms aren’t the only place you can observe smooth muscles in action, in fact all you have to do is look in your own gastrointestinal system. I suppose this is easier said than done but if you pay attention you can at least feel the effects a little bit.  Smooth muscles line the intestines and their characteristic peristaltic contractions are responsible for squeezing the digested food further and further down the GI pipe.  You can’t feel this in action but you can feel it secondarily a little bit earlier on in the digestive system if you pay attention.

If you’ve ever taken a really big bite of food, upon swallowing you may have experience the awkward sensation of that food being “stuck in your throat”.  A common reaction to this is to drink something in order to force the food down or make a few hard swallows.  If you didn’t take that big swig or do some forced swallows in the still of your post bite moment you may have  start to feel the food inch its way down further and further. That is peristalsis. 

Swallowing is, for the most part, an involuntary reaction and once the food is just a few inches beyond your mouth it is out of your control.  Imagine a conveyer belt that is wrapped around to make a cylinder. Once the food is on the conveyer belt it is on a one way trip to its next GI destination.  The conveyer belt example falls apart a bit because the conveyer is ultimately arranged as a circuit the moves along with the transported item until it reaches its end then is returned, usually below and out of site to the beginning of the transport area. The smooth muscles don’t move along with the food, they stay in place and just push it farther along. 

A better example is a pitching machine.  Imagine a pitching machine with its two large rubber wheels spinning in opposite directions.  After you manually feed the ball into the hopper it is committed and it gets shot out the other end while the rubber wheels remain in place.  If you lined up a bunch of pitching machines in series so the ball was continually fed into the adjoining set of spinning wheels that would be more like peristaltic contraction.  It would also be awesome to see. Perhaps not as awesome as watching a worm move across the ground, but pretty close.

*In fairness I must also thank my lovely wife for pointing out the great congregation of worms we had in our yard tonight. Thanks for knowing what I like!

Urban Farmer- (Saving Up for a Pet Store)

I recently learned that my oldest brother has been farming worms for the last year or so.  That is so cool.  Equally cool, but even more surprising, is that when I suggested we keep worms in our basement my wife didn’t immediately recoil but actually inquired more about the logistics of the venture. 

Before describing the theory and methods behind urban worm farming you may be wondering why farm worms in the first place.  There are actually a few good reasons to keep worms.  Worms are decomposers, meaning that they break down dead organisms and therefore are the last stop on the food chain.  Really it could be better said that worms are the first step in reintroducing useable molecules to primary producers and therefore squirm round at a pivot point where the food chain begins and ends. It is this molecular hinge function that motivates a worm farmer. 

As with anyone, urban worm farmers produce waste in the form of uneaten and discarded food.  Apple cores, egg shells, coffee grounds, etc. These are all forms of food that we are unable to, or in some cases are unwilling to eat, but for a worm they represent nutrient rich food sources. It may seem like an odd form of worm heavy altruism to keep worms on hand only to provide a food source for them but they give more thank they take. 

Of particular interest is nitrogen.  Nitrogen is a key nutrient for plants to grow but it is also a limited resource.  The atmosphere is 78% nitrogen but all of that is inaccessible to plants.  Worms are handy because as they consume the discarded organics around them they process the complex molecules and break them down into more simple parts.  In this way the nitrogen locked in a banana peel or a fallen oak leaf becomes accessible to the plants in the form of delicious and earthy worm poop.

I haven’t been over to check out my brothers operation but as he describes it, it sounds like a pretty simple and elegant set up.  The farm consists of two large Rubbermaid tubs with holes cut out of the bottoms. The tubs are filled with dirt and stacked on top of each other.  Plant based foods are buried in the bottom of the top container along with a few dozen red worms. The worms eat and process the food waste until it is gone.  At that point the worm filled bin is moved to the bottom and food is buried in the new top bin.  The worms make their way through the holes toward the food in the top bin leaving the nutrient rich worm castings (poop) in the bottom bin.

Simple, awesome, worms.

The Essentials – A Survival Story

Last April I walked across the parking lot into work after a long spring nights soaking and was greeted by thousands and thousands of worms.  I couldn’t help but walk in a little slower that morning as I pondered the worms paristalticly parading across the pavement.  

This is what I remember observing and thinking that day.

As I walked from my car to the front door at work one rainy April morning I noticed 100s if not thousands of worms sprawled across the expanse of the parking lot.  There were small worms and big worms, and all were completely stretched out, presumably in an attempt to not drown in the supersaturated earth.  My first thought was that if a guy wanted to collect worms this would be a great time to do it.  This in fact is a favorite childhood past time for many people. I remember a lot of good times collecting worms on a rainy day or soaking an area of the lawn to collect worms before going fishing. As useful as this phenomenon is for would be fisher kids, to a worm this is a survival mechanism.

 I don’t know enough about the biology of worms at this moment to comment very specifically but I am aware that worms have a nervous system and a capacity for some sensory responses but they are not on level with mammals or fish or other higher organisms in terms of intelligence, decision making or anything like that.  What worms do have is a survival instinct.  They have an instinct that triggers a response if they are in danger of suffocating because the ground is filling with water just as people have a survival instinct of getting out of water if we are being held under water and couldn’t breathe. Our instinct, like the worm’s, is to get out.  Worms don’t have the capacity to want. Worms have an instinct (or nature or biochemistry or whatever you want to call it) to get out in order to survive.

As a result of this instinct, as I was walking into work that rainy April morning, there were thousands of worms within 100 feet of me that were surviving the rain. They were surviving this horrible situation, making an attempt to avoid drowning in the murky soil below. Their home had become inhospitable and as a result they fled.

Fast Forward through 8 ½ hours of work,  five delicious cups of coffee, three pieces of peanut butter toast, a bowl of delicious lasagna supplemented with hard boiled eggs and tobacco sauce, I emerged from work having survived it (having satiated my instincts for survival by eating all of that food of course).  I emerged to find, not all of the worms, but many of the worms, as worm carcasses, splayed out across the blacktop. Dead.  These worms were not survivors. They followed an instinct to get out of a situation that would have surely caused their death but their response also caused their death.

Not all fleeing worms however, remained to die on the blacktop. Some of the worms went back to the soil, some of the worms found higher ground or found a moist place that would not consume them and fill their little membranes with the aqueous poison that would subsequently claim their fallen comrades. In short, they survived. This is the battle worms fight every time there is a rain, every time their home becomes inhospitable to life. They have to survive it.

Those worms that return and continue burrowing through the ground once it dries out a bit and especially those worms that procreate (that is go have little worm babies) with other worms, those worms survived.  Not just as individuals and not just in terms of their family name or to live another day.  Their specific genetic makeup survived the flood and those genes became more likely to be passed on to the next generation of worms.

 Perhaps if there is something about the survivors genetic make up that caused them to have an affinity for higher ground or sensed a finer range of moisture levels that would be hospitable or if they just got lucky, their genes will go on and the genes of their mates on the blacktop will not.  

So some of the worms survived, some of them did not, some of the gene variations will be passed on, some will not. In this story, and in an evolutionary sense, genes are the ultimate survivors.

While this is quite a harrowing tale it is certainly not the picture of survival of the fittest that is painted by some authors regarding cruelty or violence between organisms.  There is certainly no direct conflict or fight between two individuals.  This is not the story of the lion tracking and stalking a gazelle to catch it and rip open its throat to subdue and eat it (though that is certainly also an example of something surviving and something not surviving and ultimately linked to the survival of genetic material).

The worms give us a survival story with evolutionary consequences but not the type of survival we always think of. This is characteristic of evolution in a lot of ways. To understand and accept evolution we have shift our paradigms toward those of greater and more minute scales than we often have the mental capacity to comprehend (I know it’s the case for me). 

How long is a billion years?  What is a gene? How is a gene expressed and what impact does that have on me? These are mind bending questions and questions that we ultimately have little to no frame of reference to answer unless we examine them intentionally and with tools that are useful for exploring them.