Walkabout podcast – But how? Part 3
For the next part of this series, we take a look at one of the more interesting aspects of the religion/evolution debate, that of complexity. This one is much more the victim of misunderstanding (and intentional misinformation) than the previous two, which require the effort to see things from a different perspective more than anything else.
While the concept of complexity has been brought to the forefront by the intelligent design movement, it’s long been one of those things that makes many people wonder how simple evolutionary processes can produce it – or, too often, categorically deny that this is even possible. Single-celled organisms are one thing, but just looking at the myriad processes in our own bodies is enough to make one wonder how such interacting, interwoven, complicated things can come about without guidance. And unlike many religious arguments, I actually identify with this one because it has some legitimacy – the level of detail is astounding. But it’s not enough to find it hard to believe, therefore impossible; that’s a thinking/debating fallacy called an appeal from ignorance, paraphrased as, “I don’t get it, therefore it makes no sense.” If one runs into something that’s hard to understand, this is actually a call to examine it in detail, rather than dismissing it as bunk. Not everything in the world is easy to understand, or can be explained in a paragraph or two, and I’m not going to do it justice in a blog post. I can provide only the overview, but hopefully enough of one to demonstrate that it is indeed possible; it is up to the doubter to be honest with themselves and find out more detail as needed – preferably from a source that doesn’t have an axe to grind. You know what I mean by that.
First, let’s get “irreducible complexity” out of the way. This is the rallying cry of the intelligent design movement, and a clever one, in that it seems to convey its meaning without explanation. Except that, when you ask what exactly it means, you actually get two different answers, and these change as the situation warrants. The first answer is: it means if you remove any portion of a complex organism, it fails to work, therefore it could not have evolved over time – the example given is that of a mousetrap, which will not work as a mousetrap if you remove any portion of it. The second answer states that an organism is irreducibly complex if you cannot trace back the origins of some aspect to a simpler, less complex source.
The first doesn’t often appear anymore, because it makes no sense in and of itself. If you break something, it doesn’t work as it did before – well, duh! Not to mention that it applies to designed things as much, if not more so, than it does for evolved organisms. And we, wonderfully complex as humans are, can function just fine without many aspects of our bodies, such as arms, legs, eyes, kidneys, portions of the brain, portions of the digestive tract, and on and on. All of this is needless misdirection, however – evolution has nothing to say about the necessity of any particular aspect of an organism, only how they came about in the first place. Since it is undirected, we should actually expect to see some extraneous details, and we do – look at your fingernails for a quick example. So the salient point really is, could such details have come from simpler beginnings, which is where the second definition of “irreducible complexity” comes in.
To establish this, however, we would need to show that such details (blood clotting and bacterial flagellum are the most frequently forwarded examples) do not have a simpler form, or some kind of ancestral example. But to really establish irreducible complexity as a valid concept, we would have to show the spontaneous appearance of some detail with no ancestral or base version visible in other organisms or the fossil record. This is a little tricky in the two examples given, since neither the clotting chemicals nor the bacterial flagellum show up in the fossil record, because such things cannot fossilize. So we would instead need to show that the components do not show up in a different form in other current species, and/or that other species do not use a simpler method of blood clotting. I probably don’t have to tell you that both of these examples have indeed been disproven as irreducibly complex, because simpler, source, and variant organisms have all been found and showcased. Nowhere to be found is anything that spontaneously appears in the fossil record, but even if it did, this wouldn’t really constitute proof – the fossil record is not a unbroken line of changes, but spot samples of life from various periods. It cannot be used to establish firm lineage because it is far too sporadic, so even a spontaneous appearance could simply mean we haven’t found the transitions yet. Real proof would only be the sudden appearance of a trait in an existing species, and more than once, as well.
Another point that is often missed in here is that, under the idea of an intelligent designer, change of any kind is completely unnecessary. Competition among species, adaptations, speciation, extinctions – all pointless, or at the very least evidence of gross mistakes. Intelligent design is a concept that tries to borrow the legitimacy of our scientific knowledge of species, since this knowledge is undeniably present and useful. Scriptural descriptions of animal “kinds” simply do not match what we see every day, and offer no recognition whatsoever of the myriad extinct fossilized species that we know of. The weight of the evidence rests solely with science, which even allows us to produce vaccines in rapid order for each year’s new influenza strains. People know science works and still want its authority, thus intelligent design is an attempt to disguise religion as science.
Ignoring all of that, we still have to deal with the idea that something complicated can come from something simple, most especially with nothing but natural laws guiding it. There are a few key factors to this: change/mutation, duplication, and time.
Most people have no problem accepting that small changes might occur in, for instance, a newborn: birthmarks, extra fingers, cleft palates, hair color, and so on. We know mutations and genetic drift can occur, often benign, so it means we can accept that reproduction is not free from error or change. These changes have a source, and it’s the DNA, which serves as the control center of developing cells, sometimes referred to as the instruction sheet even though this is a little misleading in itself. Changes in the amino acids are not only possible, they’re relatively common, and more than once I’ve read that the average number of mutations in any human is 100 or so. Even without mutations, there is the gene-mixing of sexual reproduction to consider, though this even has some variations to choose from because of genetic change. Can you find a genetic trait that you have that neither of your parents have? I myself have wicked bad sinuses, several problematic allergies, and weird knees, any of which could be genetic mutations, and who knows what’s going on inside?
But those are changes to existing structures or functions, and not increasing complexity, aren’t they? Unless they result in duplication, such as the polydactylism (extra toes) that is often seen in domesticated species, like the Hemingway Cats (great podcast there.) Duplicating genes is even easier, and the duplicate is often inactive – its job is already being done by the source twin. This isn’t an increase in complexity either, it’s just an unnecessary redundancy – until the duplicate changes.
A small aside here, since another of the misleading challenges to complexity is called the “increase in information.” Deniers maintain that changes to DNA do not result in increasing information, so the complex organisms we have today could not spring from the single-celled organisms that life would likely have started from. And duplication of a gene or sequence is not an increase, only redundancy. But “information” is interpreted poorly, since information within DNA is nothing but combinations of amino acids (like words are combinations of letters.) While neither change nor duplication is an increase in information, a duplication that then changes is – both steps are required, but it’s not like this is impossible, simply rarer than either step alone. It’s hard to believe this is treated as a major stumbling block, but the arguments against complexity are motivated by something other than basic science.
Now we get to the selection part. Many people have a tendency to think of this as directed to some extent, that nature is selecting the parts that work best and eliminating the rest, but that’s not quite accurate. All genes get passed on to the reproductive process, such as the egg or sperm, and will make it to the offspring unless blocked by a stronger gene from the mate, or dropped out by the same kind of changes that produce mutations. The question is, does the individual, the parent, make it to reproduction? This is where selection actually takes place. If the change to the individual from the genetic variation hampers its ability to survive to reproduce, or to be selected as a viable mate, that genetic variation may not pass on. So harmful changes/mutations have a tendency to get weeded out by selection, but beneficial or neutral changes tend to get passed along. Using the Hemingway Cat example again, those extra toes don’t generate a particular advantage, but no disadvantage either, so they can continue in the genetic line.
Should, however, those cats start swimming for some reason, those extra toes now provide a distinct advantage, as would webbing, longer legs, more body fat, and many other traits. Now, the change becomes not only an increase in complexity, but potentially a benefit over other examples of domestic cats. If their food, or greater chances to mate, came from the ability to swim, the extra toes would almost certainly start to appear more often, since those possessing them would pass their genes on more often. The swimming example is simply one that I made up that would put those extra toes to good use, and while it could be argued that cats would never have to swim, it’s actually an interesting example; they live on a small island, in hurricane central, so the chances of their environment changing to the point of less land and more water is actually quite high. Those toes would help with muddy areas too, just like snowshoes work in snow, so it becomes very easy to see how such simple changes can become useful in certain circumstances, and this is exactly how speciation occurs.
And that’s where the last element of time comes in. Genetic benefits are only tendencies, not changes to species – it takes a large viable population to maintain a genetic change throughout enough individuals and generations to create a species change. Unlike the idiotic rantings of Ray Comfort and Kirk Cameron, individuals do not produce offspring with abrupt changes, much less different species altogether; speciation takes place from very small changes built up over long periods of time (and usually isolation from another population, which might offset the genetic changes with their own lack of the same.) For instance, lions and tigers, though separate species, can interbreed, since they have not been geographically separated long enough for their genes to fail in making viable offspring, but in a few thousand years, perhaps only a few hundred, this change will almost certainly take place. Random genetic changes, unmixed between the two different populations, will eventually prevent lion sperm and tiger egg from producing a viable fetus. Small changes can and do add up, assisted by the advantages that they provide to their host species.
We don’t do well in dealing with long periods of time – we have a hard time grasping them. But 3.8 billion years, the length of time we’ve had since the first cells produced evidence of their existence in the fossil record, is long enough to accomplish many, many things, even with tiny steps. Homo sapiens left Africa about 100,000 years ago – that’s 1/38,000 of life’s history on earth, and in that time we’ve expanded across the planet, changed languages several hundred times (if communication by abstract symbolism wasn’t actually created within that time – there’s no way to tell,) and developed racial traits appropriate to our climate, like darker skin in the equatorial areas and thicker bodies in the arctic. All of the genetic changes that we call “races” among humans occurred since that migration. Counting a generation as an average of 18 years (reproductive age, and I’m being generous,) that’s over 5,000 generations. Remember that figure of 100 mutations per human, average? Some of them are bound to produce radical changes. Yet, Homo sapiens is still largely considered the same species that left Africa – Australopithecus afarensis, otherwise known as “Lucy,” is roughly 35 times older than that, and still remains in the most recent 0.1% of life’s history on earth.
While we’re at it, let’s clear up “species” as well. The bald truth is, we developed the original concept of species because it was visibly obvious – cats are obviously not dogs, and so on. But from a scientific standpoint, species can only be defined from the differences between two examples, mostly their ability to reproduce. There is no point, no recognizable change, where a species “crosses a line” and becomes something new, and in some cases biologists actually struggle to determine whether two examples are really different species or not, such as the great blue and great white herons. When we gained the ability to read DNA, we found that appearances could be deceiving, as in the case where the elephant’s closest relatives are manatees, dugongs, and rock hyraxes – not hippopotamuses or rhinoceroses as one might suppose.
“Transitional forms,” as that video clip demonstrated (I apologize for that, but Comfort and Cameron are the most astoundingly bad promoters of creationism,) is another aspect grossly misunderstood. Nobody in their right mind ever proposes one species turning into another existing species; what the evolutionary change provides for is an entirely new species. Religious apologists proclaiming that the world contains no “combination” species are simply demonstrating their profound ignorance, dismally, since this information is readily available even online. If you really want to see a transitional species, look no further than penguins, birds that cannot fly but swim exceptionally well – preyed on, no less, by sea lions, mammals that lack feet anymore (though their skeleton betrays the ancient evidence of them) that also swim better than they walk, yet still have to breathe air, not water. Both of these species, and many more besides, are completely pointless and inept from a design standpoint, and would be much better off with traits that fish have, like gills and scales. They possess the traits that they do because selection makes them work from the changes that the species have undergone in times past. Smaller wings does not do much for flying birds, but they offer an advantage to swimming birds. Fins would be better, but fish have had a much longer time to specialize in their swimming appendages, so penguins and sea lions cope with modified limbs from times when they were flying or walking species.
The funny thing is, none of this is guesswork or supposition, since the genes show traces of their lineage in many ways – two of the books that I’ve reviewed, Your Inner Fish and Why Evolution is True, talk about this in detail and cover this much better than I have here. People that have received a decent background in evolutionary theory have no issues with understanding complexity whatsoever – but not enough people have received that background. While this should be one of the many basic concepts taught in schools, we have numerous religious folk who simply can’t have that, and enact all sorts of methods to try and prevent it.
There are some interesting implications surrounding that, too, but that’s a topic for its own post.