I think it's worth organizing today's Blog around the slide (at right), in which Professor S shared his main "objectives" for Lecture 2. We never got to objective 4 today (Critter Wed.), so that leaves us to discuss objectives 1-3. However, I'm not going to spend time talking about objective 2--which had you go outside and practice developing basic models and using scientific methods. So, that means that I'm going to break this Blog up into two different discussions: "Models/Method" and "Genetics." Today's Blog will tackle Genetics. In tomorrow's Blog ("Getting ready for the quiz (Part II)") I will go back and address Models/Method.Keep in mind that I'm going to regularly refer to ideas that I put forth in my Blog about Lecture 1 (Concepts, Principles & Models Oh My!), so if you haven't read that one I would suggest going back and doing so now.
Let's get started with Genetics (objective 3)...
GENES: Is it a concept or a principle?
I told you this was coming, didn't I? I said yesterday that this course was going to make a big deal about 3 major concepts: genes, matter, and energy. But I must admit something to you that I learned in conversation with Professor S after lecture today: I was right...and I was wrong. I was correct in yesterday's Blog when I said that the concept of genes would be a really big deal in this course. Well in fact it turns out that genes, matter, and energy are such BIG concepts in this course that Professor S is calling them "principles." This is a little bit different than how I am used to hearing the term "principles" used in biology courses. And this is worth discussing in more detail...
When I've heard the term "principles" used biology before, they were used in connection with law-like statements that guide scientists' work/thinking. Have you ever heard of Occam's Razor? You may not recall off the top of your head what this is, but I can assure you it's not a shaving device. Occam's Razor is simply a saying, and it goes something like this: The simplest explanation for a phenomena is likely the correct explanation. In the everyday use of English language (sorry to those who speak English as a 2nd, 3rd, or 4th language--what I'm about to write might not translate well!), Occam's Razor is sort of a reliable rule of thumb. Occam's Razor is sometimes called the "principle of parsimony" or the "law of succinctness"--it basically translates as, 'cut the fat' or 'keep it simple' (anyone ever told you to use the "KISS principle?" i.e., Keep it simple, stupid).
So maybe now you can see why in yesterday's Blog I was calling "genes" a concept--genes didn't seem to me like a law or some kind of rule of thumb. However, after doing a little word-research today, I can now see why Professor S considers genes, matter, and energy to be "principles." When he uses the term "principles" to refer to these 3 things, he is drawing its meaning from its original Latin root principium, which means "a beginning, a first part." In other words, Professor S is saying that genes, matter, and energy are 3 important starting points (or 'building blocks') of knowledge that you should take very seriously. In (still) other words, they are the 'foundations' upon which much of the rest of the knowledge in this course will be 'constructed.' If we want to put this back in terms of concepts, then we could say that genes, matter, and energy are really really really IMPORTANT concepts or ideas in this course...they are the Queens (or Kings) of all the other course concepts!
So what did we learn about a major course principle today? What did we learn about genes?
I'm not sure how good your note taking skills are, but today in class I tracked as many things as I could that were said about genes. You might consider doing the same when we start talk more about other principles like matter & energy. The bulleted statements that I've compile below did not come from a single one of Professor S's slides today --they came from a bunch of them (only one of which I've shown on the left).Whether you realized it or not, lots of his slides had "genes" or "genetics" in the title (by the way, you should all start paying attention to slide titles). I've listed them a form used in some types of linguistic analyses, which should make it easy to see some relationships that I want you to pay attention to. Anyhow, here are some things that were said in today's class about genes:
- Genes (determine) traits.
- Genes (are related to) proteins.
- Genes (are transcribed to) mRNA (is translated into) proteins.
- Genes (are made of) DNA.
- Genes (code for) proteins.
- Genes (represent) traits.
- Genes (are sequences of) nucleic acids.
- Alleles (are variants of) genes THEREFORE Genes (have variants called) alleles.
- Chromosomes (are long sequences of) DNA (that include many) genes.
- Genes (have) locations...genes (are located on) chromosomes.
- Genes (can undergo something called) transmission.
- In BS110, it's clear that genes are one of the 'Suns' around which lots of other 'planets' (i.e., other concepts) revolve. Between now and Friday, you need to use your textbooks, lecture notes, and other resources to get a good handle on the different ways that scientists talk about genes. How do genes relate to other words like chromosomes, traits, proteins, traits, DNA, mRNA, alleles, and nucleic acids? Are some of these words more commonly used by scientists used when talking about genes in different at different scales (say, in a single cell, in a cell organelle, or in an multi-celled organism)?
- Another thing you can do is try to start formulating answers to the following questions: What are genes? Where can you find genes? What do genes do? How does an organism get its genes? How does an organism give its genes to others? Etc.
Near the end of class today Professor S showed you lots of pictures like the one to the left as he was talking about DNA. So, not only were you getting verbal and written statements about DNA in class today, but you were also getting what I will call "representations" of DNA. Representations are often drawings, illustrations or images--like those to the left--that are considered re-presentations of things.As students in BS110, you will be shown lots of representations this semester and one of your biggest challenges will be to coordinate the representations used in class (and in your textbook) with all of the other things that are spoken/written by Professor S in class (and by your lab instructors). Let me give you an example of how you might coordinate some of the words and representations in today's lecture...
As Professor S mentioned in class today, the 3 images in the slide above are models of DNA (did you notice he called them "models?" I did too...but we'll talk more about that in tomorrow's Blog) So, we know they are models of DNA, but are they also models of genes? The answer to that question depends on what you know about the relationship between genes and DNA. Go back to the bulleted list earlier in today's Blog and look for a statement that relates those two specific concepts. See one that helps? I do too.
Genes (are made of) DNA.
OK, so we've been told that we're seeing DNA in these 3 representations, but can we also infer that we're also seeing genes in these 3 images? That depends, doesn't it! It depends on how much DNA it takes to make a gene! At the very least, however, we can say that these 3 models of DNA show some part of a gene...even if too small to be an entire gene.
This type of coordination between representations and words/statements is a skill that you'll have to develop as you make your way through your science courses at MSU. We'll practice it some more through these Blog postings, but now you've got something else to do between now and Friday...
- Examine each of the different representations that were used in lecture today. For each one, try to relate them to one of our course principles (in this case, genes). Next, try to relate each of the representations to some of the other words that we saw clustering around genes, like chromosomes, DNA, traits, proteins, nucleic acids, etc.
7 comments:
your blog is interesting, i study pharmacy.. so i know a bit abt DNA, it's interesting for me..Thank you!
Thanks for your comments! It's nice to hear that the Blog is getting some use. If you continue to find the posts interesting, I would love to hear what kinds of things were most helpful/useful. Cheers.
I'm so confused... Is a concept just a small-scale principle? Why have two terms that mean, apparently, the same thing?
Very good question Anonymous...in this class, Professor S is calling "matter," "energy," and "genes" principles. More than anything else right now, this is what it is important for you to consider.
Why not just call matter, energy, and genes "big, important concepts" or, as you suggested, why not call lots of other less important concepts "small-scale principles?" My hypothesis is that some biologists are trying to say that things like matter, energy, and genes are something MORE THAN just your 'average' concept, so they call them 'foundational' ideas or 'principles' on which many other important ideas in biology are built.
To be honest with you, I too find this particular linguistic move perplexing, especially given the fact that scientists have yet another set of things that they already regularly refer to as "principles" (e.g., Occam's Razor).
So, it sounds like Prof S is saying that a principle is something that does not require testing and checking (something we assume?). But you seem to be saying whether something is a concept or principle is only about how we decide to name it. Yet, it seems to me that you could "test" Occam's Razor, but it would be really hard to "test" something like "matter" or "energy." I'm still confused.
Anonymous...you raise a really interesting point about 'testability,' something that I had not considered in the Concept or Principle? post.
I agree with you, a rule of thumb like Occam's Razor does seem like something that one could in fact "test." I also agree that things like matter and energy are defined such that they prove much more difficult to "test."
My confusion is still over the term "genes" being considered as principles. It seems to me that these are more Razor-like and less matter/energy-like when it comes to their ability to be tested. What do you think?
Ok, the principle of Occam's Razor can be tested (and pretty easily, it seems to me), but something (whether we call it a concept or a principle) like "genes" is less clear to me. You seem to be saying "genes" are testable -- how do you mean that? In a way, it seems like Occam's Razor is the solution to some problem, which allows it to be pretty easily testable. I'm just not seeing how "genes" do the same sort of thing. Perhaps it's just biologist-shorthand for something that is testable?
Either way, it seems like we need a more clear definition for concept and principle (and how they overlap). It would certainly make taking notes from textbooks more useful (trying to figure out how to understand each boldfaced term). Either that, or we abandon the concept/principle thing and just talk about testability. But, I'd bet that would make things a bunch more complicated.
Thanks for answering.
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