Childhood "Common Sense" and Evolution

Just read an interesting article on the "Childhood Origins Of Adult Resistance To Science." Since most won't have access to the actual article, I'll summarize a bit so you can get the gist before launching into my rant.

Basically, it's a review of the scientific literature examining what young children's preconceived notions of the world are and how children react when those notions are challenged by scientific facts that don't seem to make sense. As they explain in the article,

Recent psychological research makes it clear that babies are not "blank slates"; even 1-year-olds possess a rich understanding of both the physical world (a "naïve physics") and the social world (a "naïve psychology"). Babies know that objects are solid, persist over time (even when out of sight), fall to the ground if unsupported, and do not move unless acted upon. They also understand that people move autonomously in response to social and physical events, act and react in accord with their goals, and respond with appropriate emotions to different situations.

Of course, this says nothing about whether babies are "blank slates" at birth or whether there is something inherent in the way our brains are organized that allows us to easily perceive and grasp certain realities about the way our world works. I don't really know whether people are doing research on this at all, but it's an interesting question.

Regardless, by year 1, babies have developed a road map for understanding the world, and so are resistant to ideas challenging that framework. Young children understand that things fall down, for instance, and so find it hard to understand how the world could be round--wouldn't the people on the other side of the world just fall off?

This in itself is not surprising. The interesting thing, though, is the fact that kids in different cultures become able to grasp this concept at different ages, which suggests that what's going on is much more than just the timing of brain development. Something in the culture around us makes our children more or less likely to quickly accept certain non-intuitive beliefs. And Americans are among the most resistant such new ideas (according to the article). The article makes the point that in this case it's more about the way that these beliefs are presented in every day use. If something is so common it's treated as fact by those around the children, it is much easier for them to grasp that the mysterious fact is "just the way it is," even if it doesn't make sense in their world view:

Part of the explanation for such cultural differences lies in how children and adults process different types of information. Some culture-specific information is not associated with any particular source; it is "common knowledge." As such, learning of this type of information generally bypasses critical analysis. A prototypical example is that of word meanings. Everyone uses the word "dog" to refer to dogs, so children easily learn that this is what they are called. Other examples include belief in germs and electricity. Their existence is generally assumed in day-to-day conversation and is not marked as uncertain; nobody says that they "believe in electricity." Hence, even children and adults with little scientific background believe that these invisible entities really exist.

Other information, however, is explicitly asserted, not tacitly assumed. Such asserted information is associated with certain sources. A child might note that science teachers make surprising claims about the origin of human beings, for instance, whereas their parents do not. Furthermore, the tentative status of this information is sometimes explicitly marked; people will assert that they "believe in evolution."

Now these types of generalizations aren't exactly shocking. Children (and adults) will accept non-intuitive beliefs more easily if those around them treat the beliefs as fact day in and day out than if those beliefs are only put forth by particular individuals or if they are specifically marked as "beliefs" and not facts. And the article goes on to talk more specifically about how both children and adults judge the source of the information more than the information itself. But the idea gets back to something that has driven me crazy for a while. (And so begins the rant. Consider yourself warned...)

Every day of the year, people turn on light switches, use computers, drive their cars, and voluntarily get into giant metal tubes that will hurtle them through the air at 500mph. Every one of these inventions is the product of scientific inquiry. If they didn't exist and you tried to explain the scientific principles behind them to most people, you would get scoffed at. And yet, because we see the results of these particular scientific fields, we don't even think about "believing" in the science behind them. We take them as absolute fact. Similarly when it comes to medicine, we get vaccinated, swallow chemicals, and either irradiate cancer patients or give them toxic drugs (chemotherapy). Why do we do this? In all of these cases, basic science has lead to particular applications to which the general public is exposed on a regular basis. Because we see that the applications work, the science behind them is established as fact in most people's minds.

The difference, then, comes in when we talk about aspects of science that don't have real public applications, evolution being a prime example. What so many people fail to realize is that evolution is also being proven in this fashion day in and day out, but these smaller, repetitive proofs are seen only by the scientists doing and evaluating research rather than the general public. I'm not talking about the people who actually study evolution. I'm talking about people like me, who study other biological questions at the cellular and molecular level.

How does this work? Let's say I am studying gene X, which promotes cancerous growth, and it's more highly expressed in the particular type of cancer I'm looking at than in normal tissue. I want to know why it's being more highly expressed, so I want to know what proteins are binding to its regulatory region (the region(s) near a gene to which other proteins bind and determine whether you will express the gene or not). To do this, I first want to know what piece of the genome contains my regulatory region. Even though I know it's going to be "near" the gene, the "nearby" region of DNA is still much, much larger than the actual regulatory region I'm looking for. So what to do?

Well, thanks to numerous genome projects, there is now a wealth of information about not only the human genome, but also many other species commonly studied in biology. So I just open up my web browser, go to the UCSC genome browser, and look at the DNA near my gene where those regulatory regions might be hiding. If I just look at the human sequence, all I'm going to get are As, Ts, Cs, and Gs, which tells me absolutely nothing. However, given my knowledge of genetics, I know that the "junk DNA" that I don't care about shouldn't have any real function, and so if during the course of evolution there arose random mutations in the unimportant region, it wouldn't affect the organism at all. Both the original sequence and the new sequence are equally likely to remain. Random mutations in the important regulatory region, though, are likely to have bad consequences for the animal. So those animals that develop random mutations in the regulatory region are likely to be less fit and not pass on their mutated region. This leads to only animals that have the correct, functional region surviving. When we compare the sequences of organisms separated by evolutionary distance, then, the important regulatory regions are much more likely to have stayed the same ("been conserved") than the unimportant junk DNA.

So when I compare the sequences near gene X in the human, mouse, and fly sequences, I find that there are a couple of very specific regions of the genomic DNA (not in the gene itself) that are much more highly conserved between the species than its neighboring DNA. I test their function (I won't explain how--ask if you're interested), and lo and behold, the conserved regions I identified turn out to be critical in regulating the expression of the gene, while the nearby unconserved regions aren't involved at all!!

Thus, I have not only furthered my own research, but I've also reminded myself once again of the validity and the predictive power of evolution in the same way that flying safely through the air convinces people that the physics behind air flight is true.

The only problem is, I'm a biologist: I'm not the one who needs convincing. And the people that do need it will most likely never be presented with the type of daily "evidence" that pervades biological research. So they will go on lambasting scientists for pushing this horrible concept of evolution on the world, convinced of the evils that science hath wrought on God-fearing folk. And then they will turn off their lights, which they believe run on electrons moving through wires despite being unable to see them. They will leave their houses and drive in their cars, which they believe are powered by chemical combustion even though they can't see the reaction. And they will get into planes which they believe will not crash to the ground despite not being able to see the wind patterns that keep them in the air.

And the saddest part of all, is that it doesn't have to be that way. I don't think science and religion must always be at odds, and I have a number of friends who are both great biologists and strong Christians. They're just the "believe in a higher power" type of Christians rather than the "everything in the Bible must be the literal truth in order for my belief system to stay intact" type of Christians. Too bad their number seems to be dwindling in this day and age.