Of Petards and Retards

Two tales tonight of morons caught with their pants down.

First, poor BarryA at UncommonlyDense. He caught wind of the Blog Readability Test, a tool that uses some unknown criteria to report a web site's "reading level." BarryA thought he would use this little webtoy to go nyah-nyah at UD's nemeses at the Panda's Thumb:

Just for fun I inserted UD and it came back “High School,” which means that the general discussion at this blog is at a high school level. I then inserted Pandas Thumb and it came back “Elementary School.”

Make of this what you will.

Not that this little test actually means anything, but unfortunately for BarryA, he got it wrong anyway. Hetyped in the wrong URL. Pandasthumb.com, an unregistered domain, returns the "Elementary School" result. But the actual Panda's Thumb site, pandasthumb.org, returns "College (postgrad)."

Typical of a cdesign proponentsist, to jump at the first inkling of a conclusion that favors their preconceived notions, without checking to see if the conclusion is at all valid. Did he really expect a site that talks about science all day to return an "Elementary School" rating? Did no warning bells go off at all before he rushed to blog about it?

Other bloggers, as well as commenters on the UD post, have already pointed out his error. In response, BarryA says in the comments:

You are right. Ouch; I’ve been hoisted on my own petard.

*sigh* You lose again, Barry. The saying is "hoist by one's own petard." A petard is a little bomb, characteristic of mediæval siege warfare. To be hoist by one's own petard means to be blown up by your own tool of destruction. To be hoist on your own petard means, well... very little.

It's a little thing, to be sure, but I like the phrase too much to see it abused like that.

Let's move on to the next stupid, shall we?

Dinesh D'Souza.

*retch*

In his latest screed, D'Souza blames us atheists for spreading lies (LIES, I SAY!) about Christianity:

Have you heard the one about how the dumb, ignorant Christians for
centuries regarded the earth as flat until brilliant scientists like
Galileo came along with their new telescopes and other inventions to
show that it is round? This account of scientific progress can be found
in textbooks and it has also cemented itself in the popular mind.

The only problem with the story is that it is entirely false. It is
a made-up yarn that is supposed to illustrate the so-called war between
science and religion.

D'Souza's one to talk about made-up yarns. Galileo had nothing to do with demonstrating Earth was round; he provided evidence for a heliocentric model of the solar system! Of all the strawmen I've ever seen, this is one of the flimsiest and most disfigured.

Of course, given all the comments to that effect that D'Souza received on his blog, he had to add some sort of response:

Postscript: No sooner did I post than the atheists were in there,
seeking to divert attention from their Flat Earth myth by claiming that
Galileo is actually famous for being the first to demonstrate the truth
of heliocentrism. Even here, they are wrong on two counts: a) It was
Copernicus who advocated heliocentrism more than a half-century before
Galileo and b) Galileo's proofs of heliocentrism were mostly wrong. For
instance, Galileo argued that one reason we know the earth goes around
the sun is because of the ocean tides. Galileo thought it was the
earth's motion that caused the water in the oceans to slosh around!
Actually, the tides are the result of the moon's gravitational force
acting upon the earth. So Galileo was right about heliocentrism, but
largely for the wrong reasons. Count on our "enlightened" atheists to
keep getting their facts wrong.

So instead of admitting his mistake and apologizing, D'Souza has decided that Galileo hasn't contributed jack squat to science anyway. Classy.

There's a big difference between "advocat[ing] heliocentrism" and "demonstrat[ing] the truth of heliocentrism." Copernicus had a lot of fancy-dancy math to show people, but Galileo put forth observable evidence for it. As for that stuff about the tides, way to take one factoid and call it representative of Galileo's entire argument. I... I cannot believe that D'Souza is actually trying to belittle Galileo's contributions to science.

I find this especially amusing in light of the first issue of Dartmouth's new Christian magazine, the "Apologia." You see, they're trying to recast Galileo as a good Christian who deserved to be persecuted by the Church because he hurt the pope's feelings. I wonder how they'd respond if they knew their new hero was just a lucky moron who got on the good side of the atheists who write the history books.

Well how do you like that!

Apparently, Sal Cordova reads my blog. When I link to him, anyway. Of course, the son of a gun didn't link back to me. :-P

(By the way, folks, thanks for putting up with me and my politically-oriented posts lately. It's time to get back to a bit of pure, unadulterated godlessness!)

IDiot Rundown

Dacook of UncommonlyDense quote-mines a recent National Research Council report:

On Page 8 of a Report from the National Research Council there is an interesting admission:

“Natural selection based solely on mutation is probably not an adequate mechanism for evolving complexity.”

Of course the report itself supports the concept of Darwinian evolution. But I think the admission that mutation is an insufficient mechanism is significant. They invoke lateral transfer of genes as the alternate explanation:

“More important, lateral gene transfer and endosymbiosis are probably the most obvious mechanisms for creating complex genomes…”

Of course this begs the question; where did the genes come from that are being laterally transferred?

The genes come from mutation. The report admits that mutation alone is not sufficient for evolution (not a new revelation), but it's certainly necessary. The point is, you're not looking at one single genome being continuously mutated over time. You have a bunch of different genomes mutating, and then mixing and matching the parts that work to create entirely new genomes.

Meanwhile, turnabout is fair play. Several months ago, Time magazine made the insulting decision to have Michael (Fucking) Behe write Richard Dawkins' profile for their list of the year's 100 most influential people. Now, Bruce Chapman of the Discovery Institute is flustered because the New York Times Review of Books chose Dawkins to review Behe's The Edge of Evolution. Let me give it to you straight: Dawkins is respected in the scientific community. Behe is not. It's dishonest enough to pretend that they're equals without going further to say Behe is above Dawkins.

Next, the media made a hubbub over recent hominid fossils, and DI's Casey Luskin wasn't going to let the sensationalism go by untouched. Rather than write about everything that's wrong with his interpretation of the fossils, I'll just let you choose from a few other bloggers: 1 2 3 4 5. I'll just add that I found scordova's (UD) remark on the matter highly ironic:

It [sic] understandable that scientists make mistakes, but one would hope an entire scientific discipline could get at least one fact right once in a while.

Strong words, from someone who thinks ID counts as a scientific discipline.

We've got a transcript of a 2005 speech by creationist Don McLeroy, now head of the Texas State Board of Education. Texas is screwed. That might deserve a post of its own.

William Dembski apparently thinks animated .gifs and Beatles lyrics are accurate representations of evolutionary theory. This is a problem.

Finally, our old friend Michael Egnor still insists that questioning evolution in schools is a federal crime:

It’s a federal crime to violate a federal court ruling, such as the
ruling by federal judge John E. Jones banning criticism of Darwin’s
theory in the curriculum of biology classes in Dover, Pennsylvania
public schools.

There's just one problem with Egnor's logic: Judge Jones' ruling doesn't ban questioning of evolution. Questions are a good thing. It does, however, ban teaching of intelligent design, on the grounds that ID is rehashed creationism bent on sneaking religion into science curricula. (Don't believe that? Check out the Don McLeroy transcript.)

I must be a glutton for punishment

I've commented at UncommonlyDense again. The conversation isn't quite as heated this time around... at least not yet, anyway. BarryA referenced a talk at the TED conference by David Bolinski, one of those who worked on the animation The Inner Life of a Cell. He used one of Bolinski's comments to say that, since life needs molecular "machines" to survive, this poses a problem for abiogenesis. I made the case that just because something is necessary now, doesn't mean it has always been necessary:

BarryA: “If no life is posibble without these nano-machines, where did the nano-machines come from?”

Easy. Life as we know it might rely on the these biological machines, but that has not always been the case. As supply evolves, so does demand. Just as these biological machines were evolving to more accurately and efficiently do their jobs, the rest of the cell’s machinery was evolving to more efficiently utilize them.

Consider the automobile: without automobiles, American society as we know it would not be able to survive. But that doesn’t mean American society has always needed automobiles. Nor when the automobile was invented did we instantly plant a nationwide network of superhighways. Transportation technology has been evolving, as has our reliance upon said technology.

I was eventually pressed for evidence that older life forms got by with less sophisticated cellular machinery. In my research, I turned up this pretty impressive kinesin phylogenetic tree. Just imagine how much work went into accumulating and interpreting all that data... and to think the IDiots among us would have us discard all that research as irrelevant!

We'll see if that conversation goes anywhere... but I'm not counting on it.

You know my biggest mistake on the UD comments? Using the name "Hawkeye." Until now, that nickname has been associated solely with friends. It's unnerving to be referred to as "Hawkeye" by people who are most assuredly NOT my friends.

So to balance out that bad mojo... Hello, friends. My name is Aaron, but you can call me Hawkeye. ;-)

Refusing to Identify the Intelligent Designer

Ugh. Yesterday I registered as a commenter on Uncommon Descent and spent most of the day debating a band of ID cranks pretty much single-handedly.

I've done wiser things.

I initially registered to comment on Granville Sewell's absolutely stupid argument from the second law of thermodynamics, but ultimately decided that I couldn't say anything reasonable and productive about that. So instead, I commented on BarryA's post about Indian arrowheads. In his post, BarryA tells a little satire about how the arrowheads in his grandfather's collection must have been produced by natural causes, despite their obvious appearance of design, because no one can tell him who designed them. Hopefully you can see the problem with his little analogy.

Let me say that arguing with ID cranks on their own terms, especially en masse, is difficult, physically draining, and ill-advised. I tried to make a case for needing to investigate the designer even if something looks designed, without addressing other issues (like the fact that life doesn't look designed and that cells aren't completely analogous to machines). I think I very well may have failed.

Bad logic has strength in numbers. I tried to tease one aspect of their argument out into the light where I might tackle it individually, but they wouldn't have it. And in so limiting myself I probably made some bad (or at least incomplete) arguments myself. You can't blame a guy for trying.

Ultimately, though, I'm proud of myself for having been able to end on a strong note:

This discussion is beginning to get too broad, and so for now I will respectfully bow out. I only want to bring attention to my initial comment: BarryA wanted to say that you could tell something was designed without knowing who designed it or how it was designed/manufactured. However, to do so, he made an analogy to something for which we DO know about the designer.

As of yet, no one has given me an example of something (other than life, as ID claims) that is generally accepted to have been designed, but for which we have absolutely no idea who designed it or how. We’ve seen a lot of hypotheticals (computers on Mars, messages from extraterrestrials), but I point out that each of those examples of suspected design would be accompanied by an investigation into the nature of the designer. Why, then, does such an investigation not accompany ID?

Cheers,
–Hawkeye–

As of this morning, there have already been a number of responses but no satisfactory answers. One poster, "nullasalus," says that knowing the designer is "simply outside the scope of things" without justifying why that should be the case. "Jerry" dismisses my question as a "tired cliché." "Atom" responds with such things as Viking artifacts in North America, which of course doesn't answer my question because we do have a clue as to who designed those artifacts (surprise! we think it may have been Vikings!).

I meant it when I said I was bowing out of that discussion... one can only butt heads with the UncommonlyDense for so long before you get a headache (or suffer brain truama). I know I probably didn't sway anyone against whom I was arguing, but I have some small hope that I may have planted some questions in the mind of a passing visitor.

I'll certainly think twice before commenting at UD in the future. There's just too much that's wrong about ID to overcome in a handful of blog comments.

Bill Dembski: debunking his own side's math?

Today, Bill Dembski gives us a curious little look at his recent work:

We [Robert Marks and I] have also just finished a paper debunking the statistics of James Cameron et al. (go to www.jesusfamilytomb.org), who have claimed both in a documentary on the Discovery Channel and in a book titled The Jesus Family Tomb that the pattern of names in a tomb found outside Jerusalem matches names in Jesus’ family so closely that it is highly probable that this is in fact the family tomb of the New Testament Jesus. Since “Jesus son of Joseph” is buried there, this would indicate that Jesus himself is buried there. The implication that the Resurrection is a hoax is immediate.
. . .
Question: You think any of the skeptic societies might be interested in highlighting this work debunking the Jesus Family Tomb people? I’ll give 10 to 1 odds that they won’t. Indeed, how many skeptics now believe that we’ve found the tomb of Jesus? And to think that until just recently the skeptics didn’t even think that Jesus existed (go here).

Um, if no one's interested in Dembski's paper debunking the fuzzy math used in Cameron's documentary, it'll only be because it was already discredited dozens of times over before the documentary even hit the air. Is he really that detached from the scientific community?

Meanwhile, he gives this baffling tie-in to intelligent design:

This work is tangentially relevant to our discussions at UD about intelligent design because the Jesus Family Tomb people are claiming to show that small enough probabilities demonstrate that Jesus is buried outside Jerusalem. Prof. Marks and I show that the probabilities really aren’t that bad. In light of the probability arguments that keep being made for and against evolution — the most notable recent case being in Michael Behe’s Edge of Evolution — the arguments we make in our “Jesus Tomb Math” paper will have a familiar ring.

Okay, let's look at this. Cameron et. al. in "The Lost Tomb of Jesus" claim that the probability of finding these names in a tomb randomly is so small, that it must be the biblical Jesus' family. But Cameron's math is fundamentally flawed, which means his conclusions are without merit. Michael Behe in "The Edge of Evolution" claims that the probability of beneficial mutations occuring at random is so small, that complexity of life must be the result of intelligent design. But Behe's math is fundamentally flawed, which means...

... is Dembski trying to debunk Michael Behe?

Now Dembski is cybersquatting on reality?

William Dembski over at Uncommon Descent has a new strategy for improving the public image of intelligent design: blatantly misleading domain names.

In my previous post, I cited a Miami Herald article that refers to “The National Center for Science Education, a pro-science watchdog group.” For the real pro-science watchdog group, check out the following links:

* www.pro-science.com
* www.pro-science.org
* www.pro-science.net

That’s right. I own those domain names and they all refer back here. Let me encourage all contributors to this blog to use these domain names in referring to UD when they email Darwinists.

Someone should really tell Dembski that simply repeating something over and over does not make it so. Intelligent design is not science, and those who endorse it are not pro-science. And it doesn't even stop at intelligent design: UD is a bastion for everything anti-science, including global warming denialism, HIV/AIDS denialism, even Holocaust denialism.

Maybe Dembski's just mad that intelligent-design.net was taken. Or maybe he's smarter than we give him credit for, and he's just generating demand for those domains so he can sell them to someone like the NCSE at an inflated price.

Iowa State = Auschwitz?

I'll be the first person to appreciate an apt reference to the Nazis. Fascism, despite what you may have heard from the WWII propaganda mill, is a political movement, not the sword of the Antichrist. Hitler was a human being. It could all happen again.

But there's apt consideration of events and evidence, and then there's emotion-laden hyperbole. And when you invoke the Holocaust in reference to a guy who got turned down for a job, well... it doesn't do a heck of a lot to further rational discussion.

DaveScot at Uncommon Descent has posted the poem "First they came...", inscribed at the Boston Holocaust Memorial, in dedication to Guillermo Gonzalez, an ID proponent who was recently denied tenure at Iowa State.

If nothing else, this provides an elegant example of Step Four in denialism blog's brilliant Crank HOWTO.

Super mushrooms and fishy fingers

Oh, to be a mycologist in this day and age! A paper was just published in PLoS ONE by Dadachova et. al. describing the effects of ionizing radiation on the growth of melanin-containing fungi. Many fungi produce the pigment melanin; it's what makes your average dark mushroom dark, and is chemically the same as the pigment your skin produces to give you that summer tan. As it turns out, melanin-containing fungi have a significant growth advantage over non-melanin fungi in the presence of ionizing radiation, such as at the site of the 1986 Chernobyl disaster. The paper demonstrates that the electron properties of melanin are changed in the presence of radiation, and that growth increases according to a number of different assays. Based on this and previous evidence, they "cautiously suggest that the ability of melanin to capture electromagnetic radiation combined with its remarkable oxidation-reduction properties may confer upon melanotic organisms the ability to harness radiation for metabolic energy."

I remain skeptical for now, but it's certainly exciting enough to be worth further investigation. The paper already addressed two concerns that I had: the effect of temperature, and the effect of shielding. The paper did a fair job demonstrating that the increased growth of melanized fungi was due neither to increased temperature (melanin normally is thought to disperse absorbed radiation as heat) nor shielding against radiation damage. The next major step, as they say in the paper, will be finding a mechanism by which melanin might contribute to metabolic energy. Furthermore, I'd personally like to see what ranges of radiation (frequencies and intensities) can impact growth, and to what degree. The better we can characterize the effect, the better we may be able to understand when and how such a mechanism evolved, and where we might find it elsewhere in nature. And, of course, since so many other organisms produce melanin, can they harvest radiation for metabolic energy in the same way?

The implications are exciting, both in terms of understanding biology and finding possible applications. Space travel immediately comes to mind; space is rife with ionizing radiation, and a radiation-eating crop of mushrooms would be a great asset.

Of course, leave it to the folks at Uncommon Descent to sour a perfectly good find. "Dacook" writes:

The question naturally arises; whence came this unusual ability? Where in the evolutionary past of fungi are the Chernobyls or other high radiation environments? How will Darwinism explain the development of this surprising trait? Why ON EARTH would fungi need this ability?

Certainly for panspermia to work, there must exist organisms that can survive the rigors of space travel, including radiation. We already know about bacteria that can do this. Now we have another possibility.
And another difficulty for Darwinism.

Yes, of course, because radiation is completely man-made and never comes from natural sources ever. Dacook is basically saying that, for fungi to have evolved a mechanism for harnessing high levels of radiation, they must have been exposed to high levels of radiation. Since no nuclear reactors existed when the fungi first evolved, they must have been designed in advance. This line of reasoning completely ignores the fact that these fungi encounter radiation all the time, just not to the degree of that at Chernobyl. Our planet does orbit a giant nuclear fusion reactor, after all. If melanin has a role in metabolism, it isn't likely to be exclusive to Chernobyl-level radiation. The mechanism would have evolved under less extreme circumstances, and is only now going into overdrive in the presence of intense electromagnetic radiation. I consider it to be analogous to mankind's current obesity problem. Our bodies evolved on a low-fat diet, and as a result became quite adept at storing energy. Now that we have McDonald's (the Chernobyl of dining options), our bodies have access to more fat than it knows what to do with, but we keep on storing it, because that's what we evolved to do. It's not that we were designed to get fat and happy off cheeseburgers. We're just using an old mechanism to tp into a new energy source. The same goes for the fungi; they weren't designed to munch solely on Chernobyl glow, they're just making extra use of a mechanism they already had lying around.

As for further evolutionary evidence and the "Chernobyls" of the past, consider this paragraph from the Dadachova et. al. paper:

The role of melanin in microorganisms living in high electromagnetic radiation fluxes is even more intriguing when the pigment is considered from a paleobiological perspective. 1Many fungal fossils appear to be melanized [10], [11]. Melanized fungal spores are common in the sediment layers of the early Cretaceous period when many species of animals and plants died out which coincides with the Earth's crossing the “magnetic zero” resulting in the loss of its : “shield” against cosmic radiation [12]. Additionally, radiation from a putative passing star called Nemesis has been suggested as a cause of extinction events [13]. The proliferation of melanotic fungi may even have contributed to the mass extinctions at the end of Cretaceous period [14]. A symbiotic association of plants and a melanotic fungus that allows for extreme thermotolerance has been attributed to heat dissipating properties of melanin [15]. Melanotic fungi inhabit the extraordinarly harsh climate of Antarctica [5]. Hence, melanins are ancient pigments that have probably been selected because they enhance the survival of melanized fungi in diverse environments and, perhaps incidentally, in various hosts. The emergence of melanin as a non-specific bioprotective material may be a result of the relative ease with which these complicated aromatic structures can be synthesized from a great variety of precursors [2], [4], [5], [16]–[23].

It's truly fascinating what can be found in the fossil record.

On the subject of faulty reasoning coming out of UncDesc: PaV warps the interpretation of a new finding in fish genetics.

First, a little background in this study (please excuse any inaccuracies, I'm trying to sum up based on what little I know of Hox genes). Development in vertebrates is largely driven by a family of genes called the Hox genes. In tetrapods (four-limbed critters, like lizards and people), there are two stages of Hox expression, with the latter stage resulting in hand development. Zebrafish, the model organism for studying fish genetics and a favorite of developmental geneticists, only have one stage of Hox expression during development, resulting in fins. Therefore, it has been hypothesized that the transition from fins to hands involved adding a stage of Hox expression.

A recent study looked at gene expression in the paddlefish, which is thought to be evolutionarily very old (paddlefish today are genetically very similar to their ancient ancestors). The paddlefish, it turns out, has two stages of Hox expression (like tetrapods) instead of one (like zebrafish). This suggests that, instead of starting with one Hox stage and adding a second in the transition from fins to hands, fish started with two Hox stages and zebrafish just lost a stage over time. That is to say, some of the genetic setup for hand development might be a lot older than we thought.

That's all well and good. Then PaV makes this gaff:

"This is the first molecular support for the theory that the genes to help make fingers and toes have been around for a long time—well before the 375-million-year-old Tiktaalik roseae, the newly found species discovered in 2004 by Shubin and colleagues. Tiktaalik provided a missing evolutionary link between fish and tetrapods and was among the first creatures that walked out of water onto land." (Taken from PhysOrg.com. Here’s the link.)

Poor old Tiktaalik roseae! It’s [sic] fifteen minutes of fame is [sic] over. So much for “a missing evolutionary link”.

Correct me if I'm wrong, but fish don't have hands, yes? Even if the Hox genes themselves and certain aspects of their expression were around before Tiktaalik, there had to have been some evolutionary change that gradually turned fins into hands.

PaV continues more seriously in the comments of his post, talking about genetic "front-loading," the idea that information was lying dormant in the DNA, just waiting for a chance to make a name for itself. I don't know nearly enough about the present study or Hox expression to tackle this specific case. I'll just say that the front-loading concept seems really fishy (so to speak) to me. The Hox genes obviously had some purpose before hand development. What are your criteria for saying something was front-loaded, as opposed to just co-opted or adapted? For one thing, that presumes you know the final ideal state of the information, as well as the method for getting to that state.

Natural selection and stable equilibrium of alleles

Science Daily reports on an interesting new study of fruit fly population genetics. Fruit fly larvae have two different behavioral phenotypes, depending on which allele they have for a single foraging gene. Rovers will wander about for food, whereas sitters will stay put and nosh on whatever is in front of them. As it turns out, the two alleles are subject to negative frequency-dependent selection; that is, for certain characteristics, in a competing population, the minority has the advantage:

"If you're a rover surrounded by many sitters, then the sitters are going to use up that patch and you're going to do better by moving out into a new patch," says Sokolowski. "So you'll have an advantage because you're not competing with the sitters who stay close to the initial resource. On the other hand, if you're a sitter and you're mostly with rovers, the rovers are going to move out and you'll be left on the patch to feed without competition."

This particular case is interesting because the difference in behavior relies on a single gene, one that also happens to be homologous to genes in other species (including honeybees, mice, and humans).

It's a beautiful example of how natural selection can maintain diversity. It will be interesting to see whether they find a similar effect in the wild, where so many more environmental factors come to play in selection.

PaV at Uncommon Descent has problems understanding how this sort of system could arise via natural selection. The ignorance is hardly worth addressing, but since his post directed me to the study in the first place, it's only fair I address his concerns. He writes:

[H]ow would you explain NS being able to virtually decide that it is “best” to conserve both forms, rather than to single out one of the two forms?

And later, in the comments:

Isn’t it true that over time one trait is more advantageous than another? So, then, how does one define the “fittest”? And if there isn’t just one definition for the “fittest”, then how can evolution—the “survival of the fittest”, supposedly—make a choice? And, if it is then protested that in only certain situations this proves to be the case, then this only further obscures the equivocation that is Darwinism: Who survives? The “fittest”. Who are the “fittest”? Those who survive. Now we can add: Who survives? The “rarest”. Who are the “rarest”? Well, that all depends…..

As I initially stated, NS is virtually making a choice to “balance” these two forms. And we can see the reason why this is “good”, but we have foresight, and NS, as someone already posted, has none—it’s non-teleological, it can’t see purpose. So why does NS balance forms here, but not in the case of rhinoceroses?

Or, to put it another way, if only the “rovers” existed, would anybody be saying, “Oh, there ought to be a “sitter” population to balance them off”? I seriously don’t think so. Then how does NS ‘blindly’ come up with this ‘choice’?

First of all, natural selection doesn't "virtually decide" anything. Natural selection is not conscious, it's just a label for a process that nature undergoes.

As for how this process could result at this natural equilibrium without planning it out in advance, that should be obvious. Let's say we started with only rovers. The rovers are surviving just fine; there's no need to introduce any variation. But then variation happens, and you get a sitter. Given the current population, the sitter has the advantage being the rarer, and proliferates. It's not a choice anyone made. The sitter allele cropped up randomly, and was favored in the given environment.

So why doesn't natural selection get rid of all the rovers in favor of the new sitters? Because natural selection is a process determined by the environment. And as the sitter population changes, that changes the environment. If a sitter and a rover are surrounded by mostly rovers, the sitter will face less competition and be favored. If the same sitter and rover are instead surrounded by mostly sitters, then the rover will be favored, because the environment is different. Note that natural selection doesn't always have this effect; the increase in frequency of a certain allele doesn't always negatively impact that allele's propagation.

This particular case is a beautiful example of stable equilibrium in a biological population, and it's really interesting to think about what kind of other environmental factors (selective predation upon rovers or sitters, for example) could affect that equilibrium in the wild. It's a shame that some people have such a narrow and warped conception of natural selection that they can't appreciate how much we're learning about the workings of nature.