Priming People to Think About Small Change Over Long Time Periods

Here are the choices from a Gallup poll that periodically asks people about their beliefs in religion and evolution:

Which one of the following statements comes closest to your views on the origin and development of human beings?

A) God created man pretty much in his present form at one time within the last 10,000 years.

B) Man has developed over millions of years from less advanced forms of life, but God guided this process, including man's creation.

C) Man has developed over millions of years from less advanced forms of life. God had no part in this process.

Over the past 25 years or so, Gallup has given a poll with this question, and the answer with the most respondents has always been A, consistently between 40-50% of the population.

First of all, I think it's strange that they use the more neutral term "human beings" in the question, and "man" in the answers, but I'm not sure how much that's skewing responses.

What I was thinking about was the extent to which responses would differ if you primed people to think about small changes over geological time periods. For example, I'd like to see one group which was first asked a question or series of questions such as:

Which one of the following statements comes closest to your views on the origin of the Grand Canyon?

A) God created the Grand Canyon pretty much in its present form at one time within the last 10,000 years.

B) The Grand Canyon has formed over millions of years by the natural processes of erosion, but God guided this process.

C) The Grand Canyon has formed over millions of years by the natural processes of erosion. God had no part in this process.

You could vary it up slightly, and use other geological or astronomical entities, like Mount Everest or Mars, but I think you get the idea.

I'd hypothesize that people on the whole would be more accepting of the idea of gradual change over long spans of time without the intervention of god if presented with a less personal example than the origin of humans. I think this priming would then shift opinion when people were asked about the origins of humans.

I don't have time to do it, but it would be a fun and informative experiment. Anybody out there think that there would be no difference in the answers between such groups?

Evolution Video Games

The video game Spore just came out. It was in development for years, the brain-child of Will Wright, the guy who did all the Sims games. Supposedly Wright got input from scientists while making the game, but the game is getting mixed reviews from scientists. Some are saying that it actually spreads misinformation about evolutionary processes.



Some of the criticism I've heard is that there's too much tinkering on the part of the user to have the dynamics qualify as anything resembling evolution. Another is that the game has pre-ordained directionality: There are five stages to the game, and they always occur (cell, creature, tribal, civilization, space). Evolution doesn't work this way.

If you want to try a free video game that's a little truer to evolutionary dynamics, here's NERO, Neuro-Evolving Robotic Operatives, developed at the University of Texas at Austin. It's a combat game in which you tune the selection pressure of evolving populations of robotic soldiers in order to develop armies with particular characteristics. For example, in training mode (pictured here), your robots spawn by falling out of the sky and landing in the arena.



You can place obstacles, such as walls, or enemies, such as machine gun turrets, anywhere in the arena. When soldiers die from being shot by enemies, new ones spawn, and the controllers of the offspring are mutated descendants of the other members of the population. You can control the behaviors selected for by adjusting scroll bars. For example, you can control whether your soldiers evolve to be "kamikazes" or "evaders" by adjusting the pressure for them to either run straight at, or avoid gun fire. Once you've trained an army, you cut them loose in a battle situation and see how they fare.



Their morphologies don't evolve, just their controllers, or "brains". And this is really more a case of artificial selection than natural selection. Natural selection is pressure from either external environmental conditions or interaction with other non-human organisms that causes differential survival in a populations. For example, if the environment cools in a particular region over multiple generations of a species that has fur, like a fox, those individuals with thicker fur might be more likely to survive and reproduce, and thus more offspring in the population will have thicker fur.

Artificial selection is when the selection pressure is determined by humans. For example, a farmer is able to sell plumper, sweeter corn at market, so each time he harvests and plants, he picks kernels from the plumpest, sweetest plants to start the next crop. After successive generations, corn in this population has much larger, sweeter kernels than it did several generations ago.

Video games are going to necessarily involve artificial selection. Otherwise, the player would have nothing to do. Evolution by natural selection is an inherently undirected process, and wouldn't much make for fun game play.

I've done some work with evolutionary algorithms, and I enjoy sitting back and watching a population evolve. But I don't think this has much wide appeal. And even though NERO is a cool concept, when I played it, I didn't really think it was all that fun.

Creatures is another game series that was developed in the 90's, but I never played it. There's something appealing about the idea of playing god, determining who lives and dies in an evolving ecosystem based on your decisions, but the interaction is indirect, and its the evolving organisms that are doing most of the work.

So as much as I think the idea is cool, I don't think video games really based on evolutionary processes are going to take the gaming world by storm. However, I think if they are faithful to the science, mini-games based on evolution could be invaluable teaching tools at just about any level in education.

Spore Creature Creator

I recently downloaded the Spore Creature Creator, available here. It's a free preview of the creature editor that will come with the game Spore, which I last heard was due to be released in early September.

The creature editor is free, though it's a bit buggy, and you have to have pretty high machine specs to run it. Here's one of my early creations:


The game itself sounds pretty cool. It's from the guy who designed the Sims games (e.g. SimCity, SimEarth, etc.). I never really got into those games, but they're apparently very well done and popular.

Spore is supposed to be a massively single-player game, in which you follow the trajectory of an ecosystem from microbes to advanced, space-faring life forms. I'm not sure how the creature creator fits into the gameplay, but they did an awesome job with just this piece, so I'm interested in seeing how the game plays.

It's also interesting because I've been thinking a lot more about how to compactly represent arbitrary 3D morphologies in such a way that allows for useful designs to easily emerge via mechanisms like mutation and crossover. I wonder if the creatures in Spore will be evolvable...I originally heard about the game as an a-life game, but I don't know.

Anyway, if you're machine has pretty good horsepower and a decent graphics card, have a go.

Thinking in Deep Time

So we made it to DC in one piece. I'm here, and I'm tired, but after a good night's rest I promise to try to do a decent job of blogging the CogSci conference. I've got my packet and the schedule looks like it has some interesting stuff.

Anyway, I was just reminded of one of the dumb arguments creationists use, which is when they concede that they believe in microevolution (i.e., small changes) but not macroevolution (i.e. speciation). Sure dogs and trees and mosquitos change over time...but they're still dogs and trees and mosquitos.

To this I say: learn to think in longer time spans, people.


Sure mountains and canyons and lakes erode and change shape over time. But they're still mountains and canyons and lakes, right? I mean, who has ever seen a mountain actually thrust up from the earth's crust? That must mean that mountains and canyons and lakes were created exactly as they are, right? Because we've never seen one form before our very eyes. Because one has never been created in the laboratory.

As with geological formations, so it is with biological species. It takes a while to evolve from a single-celled individual to a complex, bilaterally-symmetrical, multicellular organism. But guess what? That's what happened.

Anyway...off to a find a decent restaurant in the area.

Hitchens Discovers Blind Salamanders While Watching TV

This article, in which Christopher Hitchens thinks he has stumbled across some sort of creationist silver bullet, is pretty funny. He was watching an episode of Planet Earth, and they came to a part about cave-dwelling animals that had lost such traits as pigmentation and eyes. This is a very old example of how species evolve, not only by increasing in complexity, but as in this case, simplifying.


I guess this is Hitchens first encounter with such an idea, though you'd think if he were fairly well-versed in evolution this wouldn't come as some kind of epiphany. He dashed off an email to Richard Dawkins, and got this reply:

Vestigial eyes, for example, are clear evidence that these cave salamanders must have had ancestors who were different from them—had eyes, in this case. That is evolution. Why on earth would God create a salamander with vestiges of eyes? If he wanted to create blind salamanders, why not just create blind salamanders? Why give them dummy eyes that don't work and that look as though they were inherited from sighted ancestors? Maybe your point is a little different from this, in which case I don't think I have seen it written down before.

If Hitchens' point is that vestigial traits are evidence for evolution, then of course it's been written down...about a million times. I'm not sure what the heck Dawkins is talking about. If his point is different from this, I don't know what it is.

So as for being some kind of novel argument against creationism, I'm afraid it's as old as the debate itself. It's a good argument...but it's nowhere near new. And it's certainly not a silver bullet. Creationists can always give some version of "if god wanted to make a salamander with useless eyes, then that is what he did." This is on par with saying that the devil buried dinosaur bones, but its silliness doesn't keep people from employing it.

PZ Myers' GECCO Talk

Update: Myers has posted his notes and slides.

PZ Myers gave his keynote address at GECCO on Tuesday morning, July 18th. Fortunately (or maybe unfortunately), he didn't breathe any fire, sacrifice any children by plucking out their heart, or butt-rape any consecrated crackers on stage.

Instead he gave a pretty darned interesting talk entitled "Developmental Perspectives for Understanding Evolution," which was basically an overview of evo-devo, with mention of some interesting recent experiments. The main argument of the talk, and evo-devo in general, is that you have to understand development to understand evolution.

One of the early slides had these two quotations:

"Everything is the way it is because it got that way." --D'Arcy Wentworth Thompson, 1917

"Evolution is the control of development by ecology." --Van Valen, 1973

Myers then went on to talk about how development is a hierarchical process that is essentially a series of binary decisions. Cells divide and differentiate, and when they do so they make choices that determine, and thus restrict, their fate. This whole bit reminded me of the most interesting part of the panel talk at last year's GECCO with Lewis Wolpert, Richard Dawkins, and Steve Jones. I didn't attend, but I have a link to the video here. The bit I found most interesting was when they were arguing whether or not it was possible to evolve a mouse with wings (which also has a wierd synergy with parts of Myers' talk, as we'll see later).

Anyway, then he talked a bit about epigenetics and the role of the environment in development, and talked about how the patterns that form during development are not directly encoded by the genes, but are an emergent effect of the process of development. He stressed that this doesn't mean that genes aren't important, just that the environment is important as well.

Then he talked about the opposite concepts of plasticity, which he defined (short version) as the ability of an organism to react to an internal or external change, and canalization, which are constraints which restrict the amount of change. As for the concept of evolvability, the capability of an organism to change, he said he didn't really believe in it as a distinct concept.

A discussion of toolbox genes then followed, in which Myers talked about how biologists used to assume that the difference in the DNA between organisms like a fly and a whale would be enormous, qualitatively, but as it turns out, about 80% of the genes in such animals is carrying out very similar functions, like determining where on the head the eyes are going to be constructed. The PAX-6 gene is a toolbox gene for use in building eyes, and both flies and mice (and by implication many other organisms) use this same gene for doing the same thing. Citing Putnam, Myers said that only about 15% of the genes are unique to an organism, in terms of their function.

Then he talked about genetic assimilation and accomodation (which Myers actually talks about at length here). He also mentioned the Baldwin Effect.

At this point in the talk he started to give some concrete examples, which was a nice way to illustrate a lot of the theory he'd been discussing. He talked about how a species of sheep that lives in a colder environment may, over time, evolve a thicker coat of hair. Or, perhaps if the climate is variable, the sheep evolves such that in warmer conditions it grows at thinner coat, and in colder conditions, it grows a thicker coat. The difference is between a kind of hard-wired trait, and one that is plastic, and can adapt to the changing environment.

Another example was from a 2006 paper by Suzuki and Nijhout, Evolution of a Polyphenism by Genetic Accommodation. Basically, the experimenters were able to artificially select for higher plasticity in the larva of the tobacco hornworm, Manduca sexta. They were able to manipulate the evolving population such that after only a short number of generations, individuals were able to change their color depending on temperature (go read Myers' post on it for all the details).

Then he brought up another cool example of the role of regulatory genes, from work by Chris Cretekos involving the differences in development between mouse and bat forelimbs. Myers' blogged about this work too. Go check it out. There are cool pics of bat embryos. Basically the researchers were able to remove regulatory genes that enhance the expression of the gene PRX1, which controls the growth of forelimbs. They spliced this regulatory sequence from the bat into the mouse, and measured the effects. Myers warned us that we weren't going to see images of mice with bat wings, and not to be disappointed. I was, a little. Instead, the mice grew longer forelimbs. Nothing like a bat's, but still longer. They also deleted this sequence in the mice and measured the result, and found that there was little to no effect, which suggests a fair amount of redundancy in the regulatory genes that mediate such kind of growth.

In conclusion, he reiterated that:

• Multicellular organisms are coherent arrays of patterned elements
  
• Organization is the product of interactions between genes, cells, and the environment
  
• Both evolution and development are dynamic processes, unfolding over time, not static lists of parts
  

The Q&A followed. I didn't take very good notes for that part, but one thing I noted was that he admitted up front that he wasn't that familiar with the field of evolutionary computation, which is fine. Though I wish he had attended a couple of sessions, especially those related directly to the topic of his talk. There was a tutorial on Generative and Developmental Systems that I really would have liked to have heard his reaction to. But in general I would have liked to have heard his reaction to some of the approaches and encodings, even if he wasn't familiar with the intricate details...just a critique of the overall approach.

But it was a good talk...better than most keynotes I've seen at GECCO in the past. In studying and trying to model cognition, I've developed a more profound respect for the role of time, and of trying to understand the extent to which certain cognitive functions have evolved to be highly plastic and which are less adaptive during our development. Myers spoke directly to these kinds of issues, and gave a very informative overview of many important concepts in evolutionary biology today.

Then he pulled a live baby out of his briefcase and bit its head off.