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I Am In Awe Of The Structure And Form Of Life

I am constantly struck by the beauty of California. Up and down the highways the state has placed interesting and unusual flora. It is spring time now and everything has come alive, shooting leaves and branches and stems into the air. Here and there stretches of highway will explode with color as a particular plant blooms. I could count a hundred different plants to and from work... trees, flowers, bushes, shrubs, cactus, etc. Most of which are flowering or soon to. Once leafless and dull, trees have shot out little leaves. It is quite pleasing to see different plants for the first time. I always wonder why they are the way they are. What shaped them into their habits and their form. This question seems to be the hardest question of all. Precisely, what is the structure and form of life and how do we explain how it came to be?

To answer that we'll need to answer many other questions. Fortunately you and I live in a time where most, but not all of them have been answered. First, we must understand the mechanisms of biology, and then the mechanisms of change. We know that genes (among other things) are inherited from parent to progeny and that inheritance isn't strict: changes take place. Your DNA (and mitochondrial RNA and maybe other things) becomes a record book. Any changes in your phenotype that will be passed on will be recorded in your genotype. Local changes, like a food shortage that makes you skinny, won't be passed on to your children. But, a change in your DNA which result in higher metabolism will.

That the genotype and local environment effect phenotype is understood. What is not understood is how the genotype expresses itself as the phenotype. What mechanism causes one cell to differentiate, multiply, and develop into different types of cells, organs, and eventually a living thing? Researchers have discovered that certain chemicals can block the replication of proteins. Each protein will have its on unique blocker and that blocker, and here's the real kicker, is regulated by the external environment. So the amount of protein made is always just what is needed, based on the hosts needs. This discovery will help us understand how a fertilized cell develops. This area of study, called embrology, is manifestly important. Again, besides obvious medical uses, an understanding of embrology enables you to understand just how the animal's anatomy develops and why. An understanding of embryology will expose the magnitude of internal contraint in development and may shed light on internal constraints with respect to evolution.

Natural selection is a negative constraint (i.e. it eliminates variation) and that the introduction of variation is caused by genetic mutation. Is mutation entirely random, or are there other factors, like the environment, which affect mutation? What is interesting is that it now seems possible for the environment to affect mutation in ways never thought. For example, an excessively high environmental pressure maybe cause riskier changes during recombination (the "gene swapping" that occurs when an egg is fertilized). Another example might be internal constraint to inhibit deliterious mutation, but an advantage mutation which allows certain new mutations could have adaptive advantage. It has always been debated whether or not mutation and selection were mutually exclusive.

But these things only describe change on a small scale. How do small changes become large visible changes? If one out of a million members of a species gains an adaptive advantage, it is statistically unlikely that the gene would spread through the population. They have a tendency to get squished out (Galton's polyhedron). More likely, many members of a population would have to gain this adaptive advantage and move in concert. What could cause the same mutation to occur in more than one organism? And if you prescribe to the theory of adaptive landscapes, an organism cannot move to a more adaptive peak unless the environment changes and the reconfigured "landscape" lands a species in a "valley". This is an interesting phenomena and it shows that once a species develops, it's going to stick around for a while, unless saltation occurs. And saltation seems unlikely, for reasons stated above. Is the environment completely decoupled from mutation rates? Mutation rates correlate with environmental pressure, but is there a connection beyond survival of the fittest?

Finally, if we can figure out how one animal functions, and we can grasp how the environment acts on said animal, then perhaps it might be possible to model entire ecosystems. The environment and all life interact and affect each other. This goes back to the whole Malthusian thing, but also to the phenotype. The phenotype is typically interpreted as the body that the genes dictate to make. This usually includes behavior, but I postulate a total accountability definition. This would include the total affect a genotype has on the environment. So if a particular species of animal has a tendency to increase CO2 but decrease O2, then that is part of its phenotype. By being able to model all of these things we will be able to do several things: a) understand the interactions between lifeforms in an ecosystem, b) understand the effects of change in an ecosystem (whether it be pollution, using fertilizer, etc.), and c) identifying problem ecosystems by pointing out things out of balance or in danger of extinction. This is important because in any system (if we assume it's closed) what goes in must go out. So if where is a misbalance, causing swarms of frogs or a bacterial epidemic, we could model these problems ahead of time AND know the cause along with its solution.

With much information, time, and lots of fossil digging, we will uncover the great mystery of life on this planet and we can build a tree of life that is confident, proud, and glorious. Indisputable in its scientific accuracy and perhaps the greatest accomplishment of man.

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