Showing posts with label bacteria. Show all posts
Showing posts with label bacteria. Show all posts

Saturday, December 10, 2011

Symbiosis - Sermon by Painting




This painting is a sermon.  It’s the foundation and basis for how I think about morality, how I struggle to live and essentially my worldview.  Captured best by the Bible quote, “It is more blessed to give than to receive,” symbiosis, or the living together of two different organisms, provides tangible evidence of sorts that cooperation works.  In fact, put better, that cooperation out competes competition.  Far from nature being a ruthless typification of, “Red in tooth and claw,”  these six panels highlight the generosity and love woven throughout life. Explanation of the six panels provided below (from left to right starting with the top row):  

1. Gaia (the Greek goddess of the Earth) is the idea of thinking of the Earth as one massive self-regulating, cybernetic organism.  This idea is also combined with a concept that life promotes life.  E.g., a tree existing in a field makes it possible for squirrels to live in its branches, eat its nuts, birds to nest in it, wasps to pollinate its flowers, the shade provides a moist microclimate for fungi and other plants, etc.  Life promotes life.  Because the tree exists a multitude of life is possible.  The other classic example from the book Gaia by James Lovelock is our atmosphere.  Because life has come before us our atmosphere now is composed of 21% oxygen (a by-product of photosynthesis), 78% nitrogen (a bacterial byproduct) and .0039% carbon dioxide (removed from the atmosphere by photosynthesis).  Without life having proceeded us to make a hospitable atmosphere we'd have a very, very similar atmosphere to our nearest neighbor Mars--95% carbon dioxide (runaway greenhouse).  Life has made our life possible--Gaia.

2. The second panel is about endosymbiosis, which is the concept that the mitochondria within our bodies, who essentially power our body by the production of ATP, are former bacteria.  This should truly hit you if it hasn’t before--the best science out there says that you aren’t one organism.   You’re the combination of at least two different critters that have become so mutually dependant for the last 2 billion years or so that we’re inseparable now.  Evidence for this can be seen that mitochondria has its own set of DNA (a plasmid just like bacteria, which is very important for phylogenetics), that they divide just like bacteria (which is why it’s important for genetics; it passes uncombined with another sex cell from the mother’s egg cell.  Meaning you only have your mother’s mitochondria, not your father’s.), they have peptidoglycan cell walls like bacteria and so on and so forth--basically they are *just* like a bacteria.  Billions of years ago an anaerobic bacteria (“us”) combined with a aerobic bacteria (our mitchondria) to create a cell that could survive in either condition.  We teamed our forces and made all complex life, including us, possible.  Go cooperation!

3. The next panel highlights how we’re a host for bacteria.  I’ve seen vastly varying numbers, but one source said that humans are generally composed of somewhere around 10 trillion cells.  Guess how many bacteria cells you have on and in your body?  Around 100 trillion!!  So, not only are you the combination of at least two different bacteria, but by cell count you are 10 times more actual bacteria than human!!!  Why?  Because that bacteria, generally speaking, majorly benefits us by breaking down organic matter that our body isn't good at breaking up--you can thank bacteria for helping digest carbs, proteins and fats as well as producing essential vitamins like vitamin K and many B vitamins.  We depend on trillions of other organisms just to eat.

4. Maybe around a billion years ago life had a great idea.  Let’s not just cooperate in energy production (endosymbiosis) and structure/division of labor (multicellularity) but also genetically--thus sex was born.  By combining genes the best of one organisms genes can be put with the  best of another’s.  Contrast that with bacteria that mostly evolve through random mutation--which is more often than not quite deleterious.  We sexually reproducing organisms survive and evolve by teamwork.  We pool the best of what we have and create something even better--synergy.

5. The 5th panel highlights the interconnection of our foods--the substances that make our survival possible.  Plants cooperate with bugs to transport their DNA to reproduce in exchange for a tasty, nutritious treat of pollen/nectar.  That’s why flowers exist.  Their beauty is a physical display and celebration of cooperation.  The same is true for fruit. Fruit exists to give nutrition in exchange for seed dispersal.  

6. The final panel focuses on the love of a mother and child.  From a biological perspective that mother needs the child to pass on her DNA and the child needs the mother for nutrition and socially relevant information for future reproduction and survival.  From an experiential perspective the two experience a level and power of connection and love unrivaled in the universe.

The Bible speaks truth--it is more blessed to give than to receive.  Why?  Because it works.  The winnowing pragmatism of evolution proves it.  If we try and live our lives in defiance of this truth we only hurt ourselves.  Cooperation out competes competition.  We ought to make this the basis of every relationship, government, family, economic system.  It works.  To paraphrase Ben Franklin, we shall hang together or surely we shall hang apart.

Saturday, May 28, 2011

The Speed of the Small





  • Neural Impulses
    • From .1-100 m/s
      • Muscle position nerves--119 m/s
      • Pain--0.62 m/s
      • Touch--76.2 m/s
      • Thought--25 m/s
    • Speeds are affected by...
      • Temperature
        • Warm blooded animals are faster
      • Pathway width (axon size)
        • Wider is better
          • Giant squids living in the arctic have huge pathways (axons) to make up for the cold temperature and having no insulation (myelin sheathing).
      • Insulation (myelin sheathing)
        • Vertebrates have insulated nerves and therefore way faster impulses
          • Quite a difference is made--1 m/s  (inverts) vs 100 m/s (verts)



    • Muscle Twitching
      • Fastest: Eye twitching at 7.5 msecs (milliseconds or 1/1000th of a second)
      • Calf muscle--100 msecs


    • Reflexes
      • Fastest: vestibulo-ocular reflex (The rotation of your eyes correcting for head tilt.  You can witness this by looking in the mirror and cocking your head to the side and noticing how your eyes maintain vertical position.).  There are only three neurons in the whole system and the whole process takes 1/100th of a second to correct.
    • Sight
      • We can notice moving image frames slower than 1/16th of a second.
        • Most movies are 24 to 48 frames per second

    • Cell division
      • Some bacteria can divide as quickly as once every 9.8 minutes
    • DNA Translation
      • The RNA polymerase can add 50 base pairs per second

    • Hearing
      • The timing difference between sounds reaching ears is known as the interaural time difference.  It's important in determining which direction a sound comes from.
        • This difference is maximally 660 microseconds (660 millionths of a second) when the sound is at a right angle to the front of the face.

    Pictures from here, here, here, here, here, here, and here.

    Works sighted [sic]:

    Monday, November 8, 2010

    Why the World (Probably) Won't Die from a Pandemic

    Bird flu, swine flu, H1N1, flu of 1918, SARS, we've had our share of pandemic scares.  All of them are very serious.  Each life lost is one too many.  Each was grave, but somehow they've pretty much faded away.  Why is that?  The triumph of modern medicine?  Well, I'd be remiss to completely discount that but it's not the only explanation.  We can thank evolution, too.

    Basically, viruses don't want to kill the hand that feeds them.

    They need us to exist.  If we're dead, they're dead (So to speak. Viruses aren't technically living).  Parasites, viruses, colds, bacteria, pathogens, infections only want to be virulent enough to cause us to transmit them, not off us completely.



    Have you ever wondered why the heck our nose runs and we cough when we're sick?



    Mucous is supposed to be a defense against a cold by filtering out airborne pathogens.  So, when we're sick already, isn't that a little bit too late to start the water works?  It does seem odd, doesn't it?  Well, yes, apparently there is a boost to antiseptic enzymes and immunoglobulins with mucous production, but the real fight is in the blood by white blood cells, not in your nose.

    So, could there be an underlying insidious explanation?  YES!  Our nose runs, coughing, sneezing ensues because we've been hijacked by viruses to become giant virus distribution headquarters!  More mucous means we're literally coughing, sneezing and dripping with the pathogen and constantly spreading it.  The most effective at spreading (the most effective at hijacking our respiration system) will survive.  They don't want to kill us; just use us for their bidding.

    How does this respiratory means of transmittance cause the pathogen to evolve?  Towards mildness.  Healthy people go out in public and spread the virus more.   Truly sick (or dead) people don't spread the virus effectively.

    Cholera is a perfect example of how virulence (potency) of a virus can evolve.  In the 1990s there was a devastating outbreak of cholera in South America that killed more than 10,000 people.  While working to cure the victims, smart scientists were also watching the evolution of the virus to see if anything could be learned to prevent or ameliorate another possible outbreak in the future.  Turns out some incredibly valuable lessons could be learned from doing this.



    Cholera is transmitted by two main means: drinking water and food handling.  In countries that had poor water supplies that were contaminated with human waste the cholera evolved to be increasingly virulent to give the person severe diarrhea to reenter the water supply.  In countries with clean water supplies the cholera was forced to be transmitted by food handling.  Guess what?  Only healthy (or at least moderately healthy) people have enough energy to prepare food for other people.  In those countries the strain became milder.



    Great 4 minute video on this: http://www.pbs.org/wgbh/evolution/library/10/4/quicktime/l_104_01.html

    Maybe that's what happened with the Black Death.  Its deadliness killed itself.  We'll never really know. (Other hypotheses exist, like resistance was developed, which may actually confer resistance to HIV/AIDS today in some eurasians."



    It's possible the same could happen with AIDS given enough time.  Typically only the healthy pass on the disease.  Only the more innocuous versions of the virus make healthy people.  Only the wimpy version of the virus survive (Hopefully.  Well, if there is a 'hopefully' talking about something so awful.).

    Bottom line is, airborne pathogens tend to evolve towards mildness and the world's water supply is becoming cleaner every day which will help with the water borne pathogens.  Hence, we probably won't die from a pandemic epidemic.

    ...I wish I could say the same for medicine resistant bacteria like MRSA...well, even that if it goes apocalyptic it will eventually have the same evolutionary constraints..."hopefully"...


    Works Sighted [sic]:

    Monday, November 1, 2010

    You Are Bacteria

    Endosymbiosis is the theory that eukaryotic cells (advanced life, like our own) evolved by the combination of simpler prokaryotic cells (bacteria and archaea).  For example, our mitchondria have their own DNA, they have ribosomes similar to bacteria, their walls and cristae look like they're bacterial and they divide like bacteria.  Ergo, they were once bacteria.

    It doesn't end there.  This theory may also explain a number of other organelles like flagella, cilia, peroxisomes, centrioles, etc.

    Really put into imaginary motion what that means.

    You aren't one thing.

    You're a host of organisms working together.

    You aren't a human.

    You're a collective of bacteria.

    It gets worse.

    If you were to count out all the cells in your body you'd get about 10 trillion or so (I've seen varying estimations of this and the next number).  If you were to count out all the bacteria cells in your gut, on your skin and every where else you'd get...drum roll...about 100 trillion.

    Let me spell out what that means.

    You're 10 times more bacteria than you are human (which is already a bunch of bacteria!!)

    Let me say it another way.

    You're about 90% bacteria.

    I hope that messes with your head some.  It has mine. :)