We are made of cells

Hi all,

At this point, everyone should be able to outline the three major tenets of the cell theory and discuss some of the evidence that supports the theory, as well as some arguments against it.  Some top-notch questions have been raised in the past few days, including:

1. If all cells come from pre-existing cells, where did the first one come from?
2. Is a virus isn't made of cells, can it still be considered living?
3. If we found another planet in the universe and it had some form of life that wasn't cellular, would we have to change the cell theory?  Can we know for sure that non-cellular life is out there?  How would we recognize it if we saw it?
4. How do we define life? Is there any validity to the categories of "life" and "non-life"?  Does it matter?

All good thoughts to chew on as we move forward in our discussion of cells.

Also, this is a cool picture of a nerve cell tissue that we discussed in class. 

Homework

Complete the four magnification problems on the worksheet handed in class.  This is your first shot at IB-style questions, so work methodically and carefully.  This assignment is not available electronically.

Further Adventures in Brain Science

I just finished reading your comments on Jonah Lehrer's "The Predictions of Dopamine," about the computer that learns from its mistakes.  Many of you expressed surprise that computer programmers would want to model their machines after our meager human brains, and others were relieved to hear that the machine apocalypse in Terminator Salvation wasn't as close as we thought.  The human brain is indeed nature's most powerful tool.  However, one of you had some insight about one way that computers do win out on us meat-sacks: "Unlike computers," this person writes, "humans sometimes don't learn from mistakes and they repeat them."  Good point!  So let's all try to strive to be TD-gammon this year, and zero in on our mistakes.

If you liked reading Lehrer, he maintains a neuroscience blog here: The Frontal Cortex.  Also, the book that we read a selection from, How We Decide, is highly-readable for any level and is chock full of more insight into how your mind works when you're not looking.  Non-required for the course, but I highly recommend it for the curious.