osewalrus (osewalrus) wrote,

Random musings on evolution

Been wanting to write this for awhile and am still too stiff to unpack.

Becky got me a copy of the "Darwin Awards" book for Father's Day. It got me thinking about the place of evolution in our societal consciousness these days. By this I do not mean the never ending fight over what to teach in school science programs. Nor do I mean the actual scientific research. I mean the role of Darwin's Theory of Evolution in our popular culture as something that everyone knows vaguely about. This wouldn't be a bad thing except for the impact it appears to have on our expectations for human behavior.

One line take: Evolution has become today what Freudian psychology and anthropology were in the mid-Twentieth century. Something that folks know vague generalisms about, prompting endless popular books, talking heads and serious misunderstandings.

Typical is this May 2 Washington Post Op Ed Piece by Richard Cohen waxing about Nicholas Wade's book Before the Dawn. Cohen (as so many others have, sadly) takes the rather straightforward fact that human beings breed and have certain traits and imposes all sorts of meanings and morals on them (for example, the idea that you "win" in evolution by getting others to rear your offspring or that we "evolved" infants that look similar at birth so that fathers would rear children that might not be theirs). But evolution has nothing whatsoever to do with winning or losing, and it isn't "designed" for anything. And, as is so often the case with enthusiasts out to prove their point, Cohen conveniently ignores any counter examples.

Allow me to review a few basics. Most of us (myself no exception) get exposed to the basics of evolutionary sciences in high school biology. We learn the very simplified story of Darwin making his observations in the Galapagos and get the basic rules of Darwin's Theory of Evolution. Notably, we learn about how the finches "evolved" specialized beaks to get at particular types of food, giving the more specialized bird an advantage. From this, we are told, Darwin deduced that creatures "struggle to survive," and that if a trait confers an advantage in an environment and breeds successfully, the offspring of the "evolved" animal will likewise have an advantage. Eventually, the "evolved" offspring will be so successful that it will (a) somehow differentiate into a new species; and (b) supplant the old species.

Some of us may have vaguely picked up something of a "pepper moth" in industrial age England that became dominant over its monochromatic cousin because the air became sooty and it camouflaged itself better. Some may also remember about pea plants and genes.

Darwin's work is, of course, good as far as it goes (Darwin no more tells the whole story of "evolution" than Newton does of "physics"), but a number of cultural misconceptions seem to flow from these poorly understood high school lessons. In no particular order, here are my pet peeves and why I wish we did more to stamp them out.

1) "Creature evolved X to do Y" I call this "creeping Lamarkism" after the French natural scientist who first opinined that creatures changed in life and passed on these changes to offspring. Thus, Giraffes have long necks in order to reach leaves in the upper branches.

This belief persists in the way people concieve of "evolution" and it produces some rather unfortunate results. First, it assumes some kind of intent in evolution. None exists. "Evolution" is a name we give to describe the outcomes of a complex set of circumstances. Evolution doesn't "want" anything or guarantee any result. But people constantly talk of critters or plants "evolving X" so that they could do Y or have some evolutionary advantage.

Sadly, creeping Lamarkism also gives a false impression that evolution is linear. Again, not so. Rather, on a genetic level, our DNA appears to work a lot like endless new versions of the Windows operating system. Each subsequent version keeps a fair amount of the junk code from previous versions, even if we don't access those features anymore. An awful lot of "junk code" seems to clutter up the space, and in some cases previous features are still there, but turned off. We don't so much linearly evolve as acquire a new set of patches that differentiate us from other users (i.e., life around us) running very much the same code with a different set of patches.

Unfortunately, people consistently confuse this constant back and forth and complex interactions of codes with a moral judgment of better or worse. There is no "more" evolved in the sense of somehow better.

Another confusion is the specialization versus generalization argument. Darwin focused on specialization, which often prompts people to think specialization is somehow better. But there is a trade off to specialization. It can make you more dependent on a particular environment or set of circumstances. The finch with a beak that works best for getting grubs out of tree trunks is in trouble if tree trunks vanish (say, because human beings bull doze the area). By contrast, the less specialized bird that gets food from a number of environments may have an edge in its ability to move to new environments.

2) "The just so story." Unfortunately, another side effect of creeping Lamarkism is that it turns a description of every living critter into a "just so" story of how it evolved some feature for a specific purpose. Cohen's belief that humans "evolved" babies that have unformed features "in order" trick cuckolded fathers into rearing children is a classic example.

In fact, alterations are by and large random (various microbiological checks do tend to produce some sorts of changes over others), or may result from unrelated phenomena. More people are right handed than left handed. This does not appear to be linked to any kind of evolutionary advantage in handedness, but appears to be a byproduct of certan complex neural relationships, themselves byproducts of other factors, all of which together produce the complex organism known as homo sapiens.

Or lets take our babies again. Sure, we can idly speculate that human males would prefer not to rear the offspring of others (rather iffy reasoning, as I explain below), and, seeing that it is really hard to tell who the actual father is from appearance, can conclude that we "evolved" this trait to keep us from killing our children. And I can speculate, best beloved, that the armadillo came about because the tortis and the hedgehog "evolved" to get away from the jaguar.

It seems a far more likely answer that human beings are born as smushy blobs because, well, we are. This being the case, I can observe that human being already spend a long time gestating and that details not related to immediate survival (such as hair and fingernails) seem to come last -- if at all. Because there is a trade off between factors of survival of mother and survival of child that has nothing to do with the behavior of the father and everything to do with how physically vulnerable a very pregnant human female is or the energy cost in gestating.

3) The single story fallacy. One of the things that is so amazing about life on Earth is the diversity of strategies. Trillions of life forms in numerous different environments exist. So why do people get fixated on a single trait or strategy and a single incident (typically mating) as the “story” of evolution?

Lets take this notion that our genes “want to reproduce” and therefore men want to sire offspring while spending the minimum amount of time and energy protecting others.

Some creatures, like salmon, seem to adopt this strategy. Female lays eggs, male comes over and sprays sperm. As a survival strategy, it works in limited circumstances.

But other survival strategies likewise work. Many of them involve not the fabled “Darwinian” struggle for individual survival, but playing the odds. Many critters form herds, tribes, and other collective groups that, as a matter of percentages, boosts the survival likelihood of everyone in the collective.

Lets go back to the fabled “cuckolded male” we touched on earlier. This time, though, I will use the Adelie Penguin as the example. As discussed in this article, http://www.calacademy.org/calwild/2004spring/stories/materialgirls.html, some female Adelie penguins will mate with single males to gain stones (the needed nesting material), then return with the stones to her chosen mate.

A little thinking shows that, as a mater of game strategy, it is no just the female, but both males (the paired male and the “extrapaired” male) that benefit. The trick is to look at the life of the penguin as a whole, not a single mating incident. Yes, some penguins will raise offspring that are not their own, a supposed “loss.” But they also increase the chances of their own egg surviving, since the female now has stones to build the needed nest. Meanwhile, the extrapair penguin has likewise improved its chances of breeding over time, because it will have a mating opportunity it would not otherwise have had. Finally, the entire penguin population enjoys an increase in survival, since it increases the chance of a penguin egg surviving by allowing a female to have access to both a supply of stones and a supply of mates.

So conventional thinking that reduces the “penguin story” down to a single, simplistic perspective and narrative (a male penguin’s one mating experience) leads one to false conclusions about what strategies “win” in evolution.

Now apply that to the human experience. Human beings seem to be doing OK for survival, there are 6 billion living scattered around the globe. Much of that success appears to rest on our behavior patterns of mutual reliance (at the family and tribe level, we also have competition between different tribes/nations). Whether a “cuckolded male” is “wasting resources” raising another child is a pretty stupid question if you look at it in the broader context of human behavior. We regularly observe that individual or bonded pair can have many reasons for outright adopting a child that has no genetic relationship, so the notion that we need to “evolve” tricks to get men to accept children seems contradicted by our daily experience. If we must try to create a “just so” story to explain why we don’t see people act like salmon, we can observe that as a matter of population survival, the willingness of a paired couple to adopt a child and of a father to rear a child that may or may not be genetically related has the same general benefit to the population of human beings as a whole, and with a multiplier effect. If I and my mate die, the willingness of my human tribe to raise the surviving child ultimately benefits the individuals in the tribe and their genetic offspring by producing additional humans to help gather food and fend off wild animals. My willingness to accept a child that might not be genetically mine is not so much a “waste of resources” but playing the odds.

4) “X is a weakness.” Again, this is a value judgment with little basis in reality. Everything in reality is trade offs. A behavior or condition is potentially a bug or a feature.

Lets take the notion that being born under developed is a “weakness.” This got played up in one of the Jurasic Park books. The baby dinos don’t know how to act like real dinos, a “weakness” because they are not born with a preformulated operating system like some other critters.

But is it a weakness or a strength? Animals born with a need to form kin groups and learn from others develop social behaviors that prove beneficial. Baby kitten’s helplessness forces it to learn more complex behavior from momma cat, and forces momma cat to teach it (or else kitten dies). This also helps kitten develop an ability to learn generally. By contrast, baby spider may be ready to run Spider 1.0 as soon as it hatches, but it will not have nearly the same ability to customize its operating system in response to its environment.

Both strategies have their trade offs, and the persistence of both (with a wide spectrum between the poles of totally helpless infant dies on its own v. completely ready to roll after birth) is good evidence that neither is “better” or “worse” in some absolute sense. But many people continue to insist on labeling these things “weaknesses” or “strengths” rather than evaluating the strategy package as a whole and seeing whether it works or not.

In short, the nice simplified story most folks learn about evolution has the unfortunate consequence of encouraging all kinds of generalizations that – if nothing else – annoy me when they get spouted back as truth by people who don’t know jack about real science. At the end of the day, “evolution” describes a process but does not predict a specific outcome. It doesn’t make value judgments, and most of the changes in a life form are neutral with regard to its chances for survival. But where I get really annoyed is . . .

4) Application of “evolution” to human behavior. Yes, at bottom (if we ignore the soul) human behavior has a physical basis. We understand, albeit only crudely at the moment, that the presence or absence of certain hormones, neurotransmitters, or other chemicals can have significant impacts on behavior. But the precise mechanisms by which this happens, the relationship between physical potential and environment, and how it interacts with consciousness remains poorly understood.

Nevertheless, it is the conceit of many a modern writer to explain why this or that complex human behavior has this or that evolutionary reason. So, despite the fact that human civilization offers a cornucopia of social interactions and parenting models, one never lacks for simplistic statements about how men or women do X or Y because we evolved that way.

And it gets worse. A book I own called “The Edison Gene” explains how ADD came about because it gives all these wonderful advantages in hunter-gatherer society. Maybe. But this is just falling back on our “just so” story. The behaviors that mark ADD may or may not have an impact on the ability to breed and pass whatever genetic information carries with it the instructions to set up brain chemistry in a particular way.

Alternatively, we may discover five years from now that ADD is entirely a function of environmental stimuli in development years or a combination of genetic propensities and environmental stimuli. But in the meantime, this is just taking an existing trait and making up a “Just So” story to explain it.

We have the same thing happening in the “is homosexuality genetic” debate. Much ink gets spilled on whether a “gay gene” would or wouldn’t be an advantage from a genetics or population genetics stand point. But does it really matter? For one thing, for most of human history, whether you preferred to have sex with members of the same gender was rather irrelevant to your official mating practices, so if there is a “gay gene” (or a propensity for favoring same sex partners n the right environment) it didn’t have much impact on whether you passed it on to your kids along with your right or left handedness or eye color.

Again, given the complexity of human behavior, it wouldn’t surprise me to find that there is a genetic propensity to favor same-sex mates that gets expressed under the right environmental circumstances. But that’s just a guess, combining the fact that deep-rooted behaviors seem to have genetic components as evidenced by (a) running in families; and (b) appearing relatively difficult if not impossible to alter via environmental stimuli after they become rooted. But it is a long way between saying “there is probably some genetic component somewhere” and believing in a “gay gene” a la “Twilight of the Golds.” (http://movies2.nytimes.com/gst/movies/movie.html?v_id=154556)

Which brings me full circle to where I started. “Evolution” has become the new Freud or the new anthropology. Where our parents would have read books about repressed libidos and how toilet training can make one successful, or about how the behavior of ape tribes or newly discovered “primitives” in Borneo or Samoa teach us generalizations about societal organization, we get books about how rape or alcoholism or politics or war are part of our “evolution” or “genetic heritage.”

No doubt something else will displace it eventually. And I could ignore it if it didn’t generate real world consequences. The “sexual revolution” was justified in no small part on the idea that “sexual repression was bad” with reference to supposed lessons from other “less repressed” cultures.

Similarly, we see writers make all kinds of pronouncements about human behavior and modes of interaction as flowing from “evolution.” I do not look forward to a world where people believe their behaviors predetermined by their genetics, or make value judgments based on an irrational belief that they need to “win” by siring offspring while not actually parenting.

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