Biology
Examining life to discern its purpose.
References: [1]
Rather Important
Life. The fascination of mankind for thousands of years. What makes us tick? What makes everything else tick? More importantly, why do we tick in the first place?
But maybe there isn't a 'why'. How should we know?
Well, that depends. How did life occur, anyway?
Biology—the culmination of basic science, and, ultimately, the study of you.
From Water to Air
So the lobe-finned coelacanth is supposed to be a prime example of the type of fish that gave rise to the first amphibians. According to evolutionary theory, a fish mutated an air breathing respiratory system and then altered its behavior so it would use it, and then also gained a survival advantage by using it so that its mutated genes would be passed on. Let's take a closer look and break down the possibilities.
For a fish to have become an amphibian, it had to have:
1) Mutated a respiratory system.
2) Gotten out of the water and breathed air.
3) Gained an advantage in the process.
For the sake of ease and clarity, I will work backwards and (ironically enough) assume that the preceding steps are proven. The last steps are always the easiest to prove, of course. It’s the prerequisites that mean the most.
So, #3. Is it possible that breathing air gave that fish-frog thingy the upper flipper? Yes; one example is that it is possible that there were low dissolved-oxygen levels in the water and supplementing its respiratory systems with the gaseous form of O2 helped it to survive. The “why?” here is a given--no fish-frog wants to die young. So we can check off #3 and move on to #2. Is it possible that a fish could have gotten out of the water to breathe (and safely back in again to satisfy other needs)? Yes; we know that salmon leap many feet, even upwards. Surely our fish-frog could clear the water’s edge. But why would it ever do so? Well, this one is kinda shaky. Every successful fish up until that point survived because it remained in the water. We know that there is no behavioral tendency in our fish-frog that would lead it to leave the water for an extended period of time, because any fish with that tendency died long before the development of air-breathing lungs. But, I suppose there are some slim chances. For example, it might have regularly jumped out of the water to catch bugs for food, and then incidentally used its lungs then. Or maybe it landed partially on shore after a jump and obtained oxygen from the air then. Now, fish aren’t exactly known for their ability to learn from stimuli. A German Shepard can be trained to recognize the implications of even subtle hand signals. Frederick the fish-froggy . . . not so much. But maybe, just maybe, our cross-training phenom was able to reject thousands of years of instinct and realize that going into the air helped him. So, although we didn’t exactly knock it out of the park on #2, we can move to #1.
Is it possible that a fish mutated an air-breathing respiratory system? Well, we know that mutations come in small amounts—a nucleotide here, a codon there. So it would have had to take many generations of tiny changes to finally create a working air-breathing respiratory system. But at the point where the lungs are only partially developed, they do not benefit the fish at all, but they take up space that other organs used to occupy, they require some of the fish’s energy to grow, develop, and function (just like any other group of cells in the fish), and make it less hydrodynamic (the extra tissue would interrupt its otherwise streamlined shape), to name a few disadvantages. So any fish that was in the process of mutating lungs would be less fit to survive, and its genes would be less likely to be passed on. It doesn’t work. Yes, lungs might make you more fit to survive, but you would have to develop them completely in one fell swoop, which we know doesn’t occur in the world around us. And why, if it were even possible to mutate such a respiratory system, would it ever do so? Well, the only reason a fish would mutate such a system would be to gain a survival advantage by becoming capable of occupying a new niche. But that is the result, not the cause, so that “reason why” is just another example of circular reasoning. The truth is, there is no material reason. The only cause could have been some outside force that imposed the mutation. Evolutionary theory suggests adaptive radiation. I suggest that that is close. Yes, there was an outside force, but it didn’t have to alter a fish to make an amphibian.
It just created it from scratch.
"But it's still possible . . ."
An interesting group of plants (genus Drakaea) mimic the appearance and behavior of a female wasp in order to trick the corresponding male wasp into pollinating for the plant. Could this adaptation have randomly arisen through mutation (assuming that a non-mimicking species already existed)? The answer is yes, it is possible. But that does not mean we should accept it as the truth. For, many possibilities exist for everything; we are ever selecting the most probable of them all. For example, if you were walking along in the wilderness one day and saw the initials "J.R." on a tree, what would you think caused them to be? It’s possible that weathering, falling debris, and temperature changes caused the bark to crack and rupture into a distinct pattern, but we know that this is not the case. Intuitively, you know that someone carved those initials. In much the same way, while it is possible that Drakaea became an expert mimicker by random events, it is not truly the case. A decoy of the right size, shape, texture, and positioning coming about, let alone the fact that it is attached in such a way as to perfectly anticipate the carrying-off behavior of the male Thynnid wasp and cause it to transfer pollen, is quite obviously not a result of random chance. In such things, intelligent design is evident.
Okay. So we're talking about biology, and we're talking about origins. Inevitably, these two subjects in combination bring up the topic of evolution. Some scientists say we're here because of it. Furthermore, those scientists cite vast amounts of evidence to back up their claim, as well as logical arguments that further support the idea. Even still, there are still people who don't agree. So what's the deal? Evolution, or not?
Before we get going, it's important to know what evolution is, and how that relates to the Theory of Evolution. If you only have a fuzzy idea, I strongly recommend following those links. If you know what it's all about, then by all means, carry on.
Why Symmetry?
The question here is, “Why are animals symmetrical, especially with respect to their camouflage patterns?” If they really were evolving, then they would have randomized patterns on their bodies. The environment in which they were and are hiding is not regular and uniform, like the symmetry displayed in animal camouflage is, but rather a disordered mix of colors and textures. Take a look at the surfaces local toads and frogs are inhabiting. They don’t have any repeating or symmetrical patterns. And yet, lo and behold, the toads (and frogs) do. Apparently, all the toads with the randomized, environment-like camo disappeared and these guys were left to pass on their genes. But of course, we know this is not the case. Besides, even if our world’s tendency toward disorder allowed for evolution, it would dictate an increasingly randomized pattern, not an increasingly ordered one. This fact cannot be disputed. Literally, all the evidence in the world indicates that the passage of time precipitates divergence from perfection and order (see “Entropy and Disorder”).
Therefore, it is infinitely more reasonable to assume that animals’ near symmetry is the result of many slight miscopies of DNA from their perfectly symmetrical parents, rather than a disadvantageous and unnatural shift towards symmetry from disorder.
Although many kinds of animals display this mark of design, toads (and frogs) provide an excellent, clear visual of the concept. If you can't (or don't want to) find any live specimens to check out, entering "toad camouflage back" into Google Image Search returns several good examples.
Phi, the Golden Ratio, and Fibonacci's Sequence
Coming Soon . . .
As we know, there are four mechanisms of evolution. The first two—natural selection and genetic drift—both reduce variety and genetic variation through the diminution of the prevalence, and eventual elimination, of certain alleles. Although it does affect isolated groups, the third, geneflow, doesn't truly constitute speciative evolution overall, since it requires the introduction of a preexisting foreign population into another preexisting one. That is, it doesn't involve a change of genes, but simply a change in which individuals are considered; in any example of geneflow, all genes in both the migratory and the original populations already existednow, they are all considered part of the native population. There is a change in the frequency of the original, isolated group, but there is no net change in allele frequency overall. The fourth, mutation, is the point of contention.
Ultimately, the problem with positing mutation as a generative mechanism for evolution hinges on the nature of information—information theory. Mutations never increase the amount of information stored in the genetic code. By replacing, removing, adding, or otherwise altering nucleotides on a strand of DNA, the original information is lost. That is, randomly changing genetic information, as one would think, increases the randomness of that genetic code. It reduces order—information—and is therefore degenerative.
This illustrates the fact that, even if they were to be helpful, genetic mutations are exclusively deleterious. For example, imagine any text—a newspaper column, your favorite book, or even this article. Now imagine that, every second, one of three things happens: one letter of text is randomly added, deleted, or replaced with another. At first, the text is still intelligible, since few changes have been made. But even at this early stage, let us consider a specific type of change.
Perhaps the word 'bat' in this article gets changed to 'cat.' New, legible information, right? Well, now the sentence would read "Perhaps the word 'cat' in this article gets changed to 'cat.'" Despite the formation of a new word, it doesn't fit with what's already there. Additionally, as random operations are continued on the text, the sentence would further degrade into something like "Zerhips te word 'kat ig thxs artnle gebts chajged yo ucat.'" This phenomenon also makes sense when considered intuitively; the greater number of constituents being of the random variety, the greater the overall degree of randomness, and, therefore, nonsensicality, of the whole.
The reason why this occurs is that there are far more combinations of letters that make no sense than combinations that form words. This holds true for the genetic alphabet as well. However, one might maintain that, despite the low chances, it is still possible that the formation of intelligible language could occur—that you could get "lucky" enough to have a low-probability outcome occur many times in a row. However, this is not realistic. Not only is a sequence of such outcomes (of the length necessary to generate any sort of message) virtually impossible (i.e., so improbable as to be impossible), such a trend is doomed to be discontinued; on a broader scale, principles of probability step in once more.
The average frequency, in this case of the occurence of a "generative" mutation, is either identical to, or very close to, its theoretical probability, which is quite low. For a message as complex as our genetic code to be created, the sequence of consecutive "generative" mutations would have to be extreme, or far from the average (i.e. there would have to be many more consecutive "generative" mutations than what would be mathematically expected). However, as a sequence is extended, it approaches its average (or mathematically expected) value, or tends toward the mean.
This phenomenon is called "regression toward the mean." Accordingly, we see that this continual run of low-probability outcomes cannot be sustained. Moreover, increasing the number of chances only drives the value closer to its expected low frequency (rarity). This is especially relevant in the case of the Theory of Evolution, which requires that there have been astronomically large numbers of chances (and vast amounts of time).
Here is an excellent presentation of the information issues with the Theory of Evolution.