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Julie G.'s picture

Descent with Modification

I'm having trouble grasping the random nature of descent with modification. I've been taking Behavioral Neuroscience this semester, and the same "randomness" notion applies to neurons in the brain (which is also mentioned in Paul's "Making Sense of the World" link). I remember when my professor in my Neuroscience class stated that neurons are spontaneously active, so stimulation is simply that which alters an already existing activity. As I understand it, Paul's closing demonstration illustrated the same thing: genes will diversify no matter what. Natural selection's affect on genes is akin to the stimulus' affect on a neuron, in that it directs already existing activity.

It's the "already existing" part that gets me. The same notion prevents me from being entirely satisfied with "The Big Bang Theory." Where did matter come from? Why did/does it exist? Why are neurons spontaneously active, and why do genes enact random modification? When Paul asked if the organisms were acting on desire, I thought, "Yes: the desire to alter in as many ways as possible." Is there a "need" or a "desire" for change? Are genes just wired, or programmed (as the electronic organisms were) to alter? If that is the case, then aren't our desires and motivations similar?

I can't help but think that, in many ways, our desires result from either our wiring (nature) or programming (nurture). Both of these things can change, and when they do, our desires change with them. For example, a basic human desire is to eat. Yet, if you place that desire within a culture that values underweight bodies, a programming change can take place: the desire to eat can be overridden by the desire to be thin. Is natural selection sort of a "programming" change for genes? Of course, a big difference here is that we can trace the need to eat back to the need for energy. In other words, the need to eat is not random; descent with modification is. Yet, how far back can we trace that need for energy. Electrons move independently don't they (it's been a while since I've studied atoms folks, so forgive and correct me if I'm wrong)? If that's the case, and electrons move independently of some external energy source, then is external energy to atoms what natural selection is to genes? A sort of director, or stimulus? But without external energy, electrons will keep on whizzing, and without natural selection, genes will keep on changing?

Why, and how, do things occur without apparent motivation? I can't seem to wrap my head around it. I always want there to be a reason, and when there isn't one, I always think it's simply because we haven't discovered it yet. Am I naive? Are there things in this universe that simply happen, or exist without cause? Can I even conceive of such a notion as possible? If it is possible, how does that affect the way I make sense of things?

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