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Mutation and Recombination

Rosie’s lecture got me thinking about my interest in the evolution of imagination, and whether it is useful to postulate ideas or memes as independent of the minds of thier hosts. Bascially, I want to test how far this metaphor can stretch, while remaining critical it might burst.

In genetics, mutations are changes within an individual, like typos in base pairs when DNA polymerase and other repair enzymes fail to spot and fix them. The rate of mutation tends to be very low, a balance between perfect copying and the physiological cost of preventing them.

Recombination of genes happens between (sexual) individuals and no one has yet been able to come up with a good theory of why it occurs when this process does more harm than good in mathematical modelling.

One of the main criticisms of the meme concept is that culture cannot be examined in bits or composed of independent units. But like religion, culture must be made up of something. Even genes do not “work” in isolation, so we should not expect memes to either. Genes used to be fuzzy and invisible too, before we could observe DNA and chromosomes; they are useful theoretical artifacts because when a sequence gets knocked out, it has some observable effect. But can a meme be knocked out and shed light on culture? Not likely.

So what would a meme be, physically? A sequence of neural connections or pattern of activity?

How would a meme mutate or recombine? Does it have fidelity, fecundity, and stability (longetivity)?

In Conceptural Integration Theory (CIT, also known as mental space theory), developed by Gilles Fauconnier and Mark Turner, a set of activated neuronal assemblies are momentarily marked off in a so called “mental space” (imagine a circle with a realistic painting of a woman as the neural pattern, composed of various parts such as head, neck, torso, color, shape, light, etc. and another circle with an African mask as the pattern, also composed of various parts such as head, shape, light, etc.), and the patterns in each space are run together in a simulated new “blended space” (imagine a new circle with Picasso’s famous painting Ladies of Avignon. This is a very crude example, but you get the idea.) Basically, the this theory looks vaguely like a venn diagram using concept maps. It has been critiqued for being fairly empirically untestable so far.

The mental spaces are short term, constructed via information stored in longer term memory networks and associations. In the example of the expression “digging one’s own financial grave,” there is the creation of two maps or “mental spaces” for the domains Grave Digging and Financial Failure, respectively. In each space, there are association networks such as Gravedigger, corpse, and death for “Grave Digging” and the unawareness of consequences, suffering, bad decisions for “Financial Failure” which are blended in a new space to make meaning of the metaphor (Slingerland 2008:178, 186). Blending allows us to conceive of “As if” scenarios, and build upon them, ideas upon ideas, memes spawning more memes.

What I want to ask, is whether this blending is similar to recombination or mutation.

A meme would be a neural pattern that codes for something very simple in a larger association network, such as the shape of a head or an eye, or changes in pitch or the identification and categorization of nouns, verbs, etc. A cluster of memes would code for all kinds of stylistic representations, images of familiar symbols, tunes and story plots. Blending creates new memes, which may be selected for or against depending on the frequency of other memes. For example, if my network of memes related to funerals included links to dark colors, grief, pain, images of dull skies, tears were to suddenly encounter links to funeral jokes, laughter, bright skies, and ritual dancing, there would be competition in terms of the strength of those connections, which links I activate more than others (weak links eventually become extinct), and these depend on the strength of the input signals which I recieve from the larger cultural meme pool. In that way, memes can be said to be independent from their hosts.

There is no blending without input into two or more “mental spaces”. Input must come from past experience and stimuli from other minds, from a memetic environment or community (like a gene pool?). These spaces (chromosomes?) “cross over” in some sense, and elements are thrown away in the process, but it is not reassembled between “two individual hosts” but in the same mind, which then can be communicated to another, etc. New ideas are often intentional, not mistakes in copying, so they don’t really “mutate” in the same sense.

Mutation happens when mistakes are made communicating between minds. It takes a long time to learn how to replicate a letter, to teach a child to write, and reproduce recognizable symbols with stability and fidelity. It takes an even longer time to copy a pattern for a fictional character, which includes all the past experiences, thoughts, feelings, actions, associations, friendships, events, yadda, yadda of that charcter (passed orally or textually, and is prone to mistakes, but there is some stability that there is agreement on someone named Anne of Green Gables or Harry Potter). Sounds may be misheard, but there is enough stability that we can trace those shifts most of the time. Instructions may be lost and the product or technology is left behind for reverse engineering. Nevertheless, there appears to be a certain rate of mutation that makes some memes more fit than others when phemotypically expressed in a cultural artefact, like some tunes that we can’t get rid of, or the ubiquitous smily face.

What does it mean for ideas to mutuate, recombine or blend? Is culture like an organism? Is this a useful metaphor?

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Nature Review on gene-culture interactions

Sorry, I totally got flooded with stuff this week… writing up my weekly blog post tonight!

But before I do so, just came across something while browsing latest Nature stuff (my Wednesday night tradition):

How culture shaped the human genome: bringing genetics and the human sciences together Laland et al. 2010 Nature Reviews Genetics

(check out Table 1 for a quick overview…)

Btw, humanities-related evolution papers are becoming fairly common in Nature Rev Genet and Trends in Ecology & Evolution (hereafter referred to as “TrEE“)

It’s really cool how you not only have several evolutionary systems going on in parallel, but also they interact with each other in both directions! Now that’s getting complicated…and thus, fun! =D

PS: A totally random thing just out today: Apparently people have actually been working on the physics and chemistry behind spiderwebs being so awesome at attracting dew drops…turns out it has to do with the spider silk nanofibre structure (Zheng et al. 2010 Nature).

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Lateral Gene Transfer Animations

I hope to really improve my presentation skills before the MURC talks, but I admit I rushed making this one, since I did not feel I was an expert on the topic. I found these really neat animations that you can watch for review:

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Population Genetics Plaything

Okay, so here’s the place you can download the really simple population genetics simulation thingy I mentioned today: http://wps.prenhall.com/esm_freeman_evol_3/12/3315/848837.cw/index.html

Your different alleles (so types of a gene, remember) are labbeld A1 and A2. You can give their respective genotypes fitness values, the higher the fitness #, the more they benefit the organism carrying them. Everything else is pretty self-explanatory, except maybe the inbreeding coefficient, which is the probability f of an individual breeding with a relative (who, by definition, is carrying the same alleles).

Anyways, to see what they’re talking about in the Lynch paper, play around with the population size and fitness levels. I have a screenshot of what I did, but cannot for some reason get it to upload on photobucket…

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Brief response to Lynch

I can’t say that I enjoyed reading this article very much; all this jargon is beginning to irk me. And then I find my mind wandering off somewhere with more sunlight and trees. Modulation? What?

My understanding is this: evolutionary biology tends to invite broad speculation on the part of non-specialists who think they’re qualified to make assertions based on their high school biology classes. (Which is why I usually only discuss this stuff when I’m drunk–no one’s going to be bothered by my baseless, uninformed opinions.) Why? Because it’s easier and more fun to fit scientific theories into one’s pre-existing ideas than basing these assertions on, say, observable data. The latter tends to take more work, an open mind, and all sorts of nonsense like that. Since evolutionary biology encompasses many philosophically sensitive topics (mostly just our creation and the reasons why we are the way we are), and since billions of years of its history are unobservable due to our irritating lack of time-travelling technologies, all sorts of people (including myself) like to butt in and dole out our two cents. In fact, the longer I take this course, the more evident my indecent lack of knowledge becomes.

But this isn’t as blame-worthy as I’ve ended up making it sound. World views are powerful forces, and not likely to change quickly, excepting some extreme happenstance. So, as we saw with that depression article, scientists of every flavor are not immune to such biases. Essentially, it’s good to remember that deeming a trait as better/worse, adaptive/maladaptive is not very useful and only marginally scientific. I like what someone wrote earlier about complexity: how do we define that, anyway? Because we tend to think that we are the most complex organism out there, just because we have invented things like the can opener and disco. Isn’t simplicity usually more stable, anyway?

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History is Strong

So to recap last week in a nutshell: we went over Phylogeny and Evolutionary Psychology, as well as Chainmail Bikinis.

Now for some musings:

Wayne Maddison’s talk on the pheneticist’s pessimism that it was impossible to reconstuct the tree of all biodiverity reminded me of a similar pessimism in Anthropology.

This pessimism is what led to “Salvage Anthropology,” the idea of recording all the variance before it “disappeared.” Cultures were static entities that needed saving or else they would go extinct. Now we look back and laugh at the idea of cultures dying, unless you are someone who has suffered from this pessimism and want your culture back.

During the early 20th century, when Social Darwinism and the idea of Unilinear Evolution was at its highest, Frans Boas was critiqued for studying his “Historical Particularism,” which is that not all effects have the same causes–we ought to examine particular case studies and history to understand how a particular society came to be as it is, not assume all societies were at different stages which culminated at Victorian Civilization (and the end of History, or Utopia, if you will).  Boas disliked generalizations (based on cherry-picking evidence to support an already established assumption) but his opposition thought that if you were to study all the case histories in the world, that everyone has their own (proximate?) reasons for doing things, it would be ultimately atheoretical–there was nothing to reveal, no overarching insight to be gained. What was the point of having a large collection of descriptions if you did no comparison work? How does that answer the big questions?

I think you need both generalizations and support from particulars: theory has to be grounded. There is nothing more practical than a good, working theory.

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MURC + proposal info

Here’s the MURC webpage including instructions for the conference, as well as the dates and deadlines, including workshop times.

The proposal description is pretty short and vague though, and I can’t find further details, so we’d probably have to wait until the workshop to polish it up. However, they do have a copy of last year’s MURC program with abstracts for some ideas. Note that the format did change a little, but until we get more info from the workshop, let’s just aim for something like those.

Feel free t0 use the comments for some brainstorming/testing ideas/discussion etc.

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test post

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Changes in appearance

What do you guys think of this? Or should we go back to the old look? Are there any pressing problems with the site that need fixing?

(Also, am I missing something or is WordPress actually less flexible in terms of layout? (than blogger). I’m trying to widen the post field slightly, but can’t seem to find where to do so.  Which is why I modified the layout, but it appears to still impose the format on me! So confused…)

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Evolution, Language and Neuroscience

Interesting podcast called Science & the City from the New York Academy of Sciences.

Nobel Laureate and neurobiologist Gerald Edelman, psychologist Paul Ekman, and anthropologist/neuroscientist Terrence Deacon tell us how Charles Darwin has influenced science and their personal careers.

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