Total Drek

Or, the thoughts of several frustrated intellectuals on Sociology, Gaming, Science, Politics, Science Fiction, Religion, and whatever the hell else strikes their fancy. There is absolutely no reason why you should read this blog. None. Seriously. Go hit your back button. It's up in the upper left-hand corner of your browser... it says "Back." Don't say we didn't warn you.

Friday, October 14, 2005

My Appreciation for Evolution

Today on Total Drek we're going to respond to Mr. Tim Therrien's remarks on the subject of evolution. His remarks are, in turn, part of an ongoing debate and my previous contribution can be found here. Sooner or later I suspect I'll organize and index all this correspondence, but for the time being this is an active discussion and we'll just see where it goes. As we start, I'd like to mention that many of the points I make below have been made elsewhere. A good summary of several is available here from CSICOP. While not as complete as my own response, it is a much shorter (and quite possibly more engagingly written) piece on evolution that discusses many worthwhile issues.

To begin with, I want to thank Mr. Therrien for moving beyond his admittedly poorly worded questions. He rightly comments that sometimes a poor question has great value but, in this case, I would also observe that his initial questions were not merely poorly worded, but also somewhat combative. I would also like to commend everyone in this ongoing debate who has tried to move this debate onto a more civil level, regardless of their position.

I am also pleased that Mr. Therrien has chosen to elucidate his intent more clearly- namely to demonstrate that evolutionary theory is not scientific. As he is not claiming scientific status for creationism or intelligent design, this should simplify matters considerably. As I have no objections to Mr. Therrien's religious faith, and have no intention to convert him to a pro-evolution position, it only remains for me to make a case in support of evolutionary theory as a scientific theory.

As we begin, allow me to make a few comments about the definitions Tim (I apologize if this seems forward, but I daresay I'll go mad if I must type Mr. Therrien throughout this post) uses.

First, the definition of theory. Tim refers to a theory as: "An assumption based on limited information or knowledge..." and further remarks that: "For the scientist, what the non-scientists means by 'theory' is actually an 'hypothesis'. I.e. - an assumption." This is, in a word, incorrect. In the present context an assumption is something that is taken to be true without evidence. A hypothesis by contrast is a proposed explanation or prediction that is subject to testing. Hypotheses are often derived from theories that are supported by evidence, so they are not believed to be true without any support. To equate hypotheses and assumptions is a mistake. True assumptions in science are more akin, though not identical, to "scope conditions," or limitations placed on the applicability of a theory or hypothesis. As we will see later, understanding the role of scope conditions is often critical to understanding the meaning of scientific work.

Tim next goes on to remark:

Since the non-scientist sees a theory as an assumption, they like to have evidence establishing the truth of an idea. We want proof. The scientist finds this anathema because they reject the idea that this is possible (which I will discuss shortly). Proof for the scientist is simply the validation of a part of any concept, which can later be shown to be false. Therefore, to request proof of evolution is to ask for an impossibility.


I think this does not fully reflect the scientific process. Scientists, like non-scientists, like to have supporting evidence for their claims. The problem is that scientists regard it as impossible to prove something to be universally true because our senses, and resources, are limited. In other words, because I cannot exist in all places in the universe at all points in time I cannot show with evidence that anything is necessarily true in all places and at all times. So, it is impossible to conclusively prove any universal statement correct. At the same time it is far from impossible to show considerable support for an assertion and an absence of successful falsification attempts.

It is also important at this juncture to comment on the difference between proving something to be true, and proving something to be universally true. I might make an assertion to the effect that, "If I lift up my keyboard right now and let go, it will fall to the floor." In order to prove this assertion correct I need only lift up my keyboard and release it. If it falls to the floor, my assertion has been proven correct. (This, of course, supposes that we do not live in a universe managed by Rene Descartes' famous deceitful god.) It is, therefore, a relatively simple matter for me to prove any particular instance of a thing to be true. On the other hand, were I to make the assertion, "Any time I lift up my keyboard and let it go, it will fall to the floor," I am in a quite different position. There are any number of additional factors which might intervene to prevent my keyboard from falling to the floor- a strong gust of wind, a sudden reversal of gravity, the intervention of my quick-thinking girlfriend, and so on. Therefore, I cannot simply and conclusively demonstrate that a universal statement is always true, even if specific instances are provable. On the other hand, I can potentially show that my universal statement is in error if, on certain occasions, when I lift up my keyboard and let it go it does not fall to the floor. This logic does, indeed, seem a little odd to most people but this is simply because we are accustomed to proving things true in specific instances (e.g. the capital of Germany is Berlin, or that individual A killed individual B) and are not used to the problems inherent in proving that some things are always true. The doubt that individuals feel about the utility of showing what is not true in order to discover what is true (Tim's included: "Build up enough of these 'what it’s not' examples and (supposedly) you come closer to what it is.") can be largely dispelled, I think, by thinking about the game of "Twenty Questions." An answer of "no" is often as informative as an answer of "yes" if the question is properly phrased.

This takes us critically into the discussion of falsifiability. Tim does sum up the concept of falsification nicely, but then proceeds to remark that:

So, one of the foundations of the Scientific Method is - by no means - accepted by all scientists. Indeed, numerous articles indicate that there are many scientists who disagree with this requirement outside the non-evolutionary scientific circle.


I think this may overstate the issue somewhat. Popper's falsification criterion is widely accepted, but that isn't to say that we don't have debates on the specific way it should be applied. Thomas Kuhn, for example, argued that falsification does not immediately cause a theory or hypothesis to be rejected for the simple reason that scientists may doubt the falsification. This doubt is no more remarkable than the doubt that results when two individuals use the same tape measure to determine the length of the same table. If they end up with different measurements, it doesn't necessarily mean that the table has changed but rather that their measurements may be in error. In Kuhn's view, we retain theories that are in the process of being falsified until something better becomes available, and then switch over. This is, more simply put, like waiting to get off of one horse until you have another one to ride instead. The seeming contradiction between a Kuhnian world in which we retain potentially flawed hypotheses, and a Popperian world in which we always reject that which has been falsified, has largely been resolved by Imre Lakatos who focusses on the competition between various approaches to solving a problem. Over time as more falsification accumulates for some approaches, but not others, those falsified theories lose adherents. As a result, falsification isn't the sudden and final event proposed by Popper but, instead, is a lengthy and cumulative process.

The real relevance of all this, however, is that while the precise functioning of the falsification criterion is somewhat in dispute, its value to the scientific enterprise is solidly established.

Along those lines, I must take up Tim's remark about the mortality of humans:

However, since Popper is considered by many to be the authority, one would have to accept that you cannot scientifically establish that mankind is not immortal. To do so you would have to demonstrate that all men, everywhere, throughout all time - die. It is not observable, testable, repeatable or refutable. You can only say that there are numerous cases where men have died. So you can say that some men are not immortal, but not all men.


This is a very sloppily phrased assertion. Science indeed cannot demonstrate that all humans are mortal. It is possible that there exists some individual somewhere who is immortal, or that at some time in the future an individual human will exist who is immortal. However, science can establish that all men are not immortal. Any single man dying would serve to falsify the assertion that all men are immortal. Further, while we can't "prove" that all men are mortal, we can point out that there is a definite lack of contrary evidence.

On the other hand, science could hypothetically demonstrate that no humans currently living are immortal. Doing so would require only attempting to kill every living human and seeing whether or not they die. I think it unlikely for both ethical and logistical reasons that such an experiment would be conducted, but the assertion is provable when phrased in a specific sense (i.e. 'currently living').

Having dealt with certain misunderstandings of the scientific method and definitions, we may now turn to the meat of the evolution discussion. We begin with the issue of speciation. Tim remarks that:

The scientific concept that seems to enjoy the most popularity is the Biological Species Concept (BSC). BSC separates “species” into very fine groupings. I.e. - “Bluegill Sunfish” and “Pumpkinseed Sunfish”. Yet both are capable of interbreeding. Although, some scientists seem to base speciation on the ability to interbreed. They point to strains of yeast, or varieties of flies that have manipulated in the laboratory and are incapable of interbreeding. BSC is not useful in discussing evolution because some questions are unresolvable. Such as “Do Homo Erectus and Homo Sapiens represent the same or different species?” We cannot know because they did not, apparently, exist at the same time or in proximity to one another in order to attempt interbreeding. Regardless, using BSC, what is often referred to as evolution is commonly held to be adaptation. Changes in species are merely adaptations to their environment. Two groups get separated for long enough and they may not be able to interbreed. But it does not change the nature of what
they are.


He is correct in commenting that the precise definition of species is in dispute, at least in part because it doesn't always match up with common perceptions and, in the case of the BSC, because not all species reproduce sexually. Therefore, a definition that is based on ability to interbreed is of little use for these creatures. However, the BSC, according to the link I sent Tim, "...defines a species as a reproductive community." Thus, creatures that CAN interbreed, but do not for a variety of reasons (provided in the link) may not be considered the same species. This is, however, a relatively minor issue.

Of greater concern in Tim's remark that:

BSC is not useful in discussing evolution because some questions are unresolvable. Such as “Do Homo Erectus and Homo Sapiens represent the same or different species?” We cannot know because they did not, apparently, exist at the same time or in proximity to one another in order to attempt interbreeding.


This is not a correct statement. To say that a given criterion is not useful in all circumstances is not to say that is entirely useless. A similar argument would be that because all cars are not Chevys and Fords, the terms Chevy and Ford are useless. The BSC remains a useful criterion in a number of circumstances, regardless of its definitional failues in others.

Finally, Tim dismisses the BSC with the following:

Regardless, using BSC, what is often referred to as evolution is commonly held to be adaptation. Changes in species are merely adaptations to their environment. Two groups get separated for long enough and they may not be able to interbreed. But it does not change the nature of what they are.


I would appreciate some links here as to what difference Tim perceives between adaptation and evolution. Evolution is regarded as an accumulation of adaptations that results in the generation of new species. Put more fully:

"In the broadest sense, evolution is merely change, and so is all-pervasive; galaxies, languages, and political systems all evolve. Biological evolution ... is change in the properties of populations of organisms that transcend the lifetime of a single individual. The ontogeny of an individual is not considered evolution; individual organisms do not evolve. The changes in populations that are considered evolutionary are those that are inheritable via the genetic material from one generation to the next. Biological evolution may be slight or substantial; it embraces everything from slight changes in the proportion of different alleles within a population (such as those determining blood types) to the successive alterations that led from the earliest protoorganism to snails, bees, giraffes, and dandelions."


As such, I see no distinction between "adaptation" and "evolution" that could make Tim's remark meaningful. As the bard remarked, "A rose by any other name would smell as sweet." In this case, evolution by any other name remains evolution.

Tim continues to attack the issue of speciation with the following:

“The literature on observed speciation events is not well organized.” Four factors relating to this include: A. Lack of scientific interest. Few researchers and grad students look beyond their assumption that the literature exists. B. The assumption is that “speciation” takes a long time, so few events would be observable. C. “The literature contains many instances where a speciation
event has been inferred . (Not documented or substantiated, simply inferred.). D. “Most of the current interest ... concerns theoretical issues.

So, as regards speciation, the literature is not well organized. The researchers are basing their research on the assumption that supporting literature exists. And the process may be too long to document so they go on information that has been inferred (rather than substantiated.) This is apparently deemed sufficient because they are more interested in theoretical issues than in establishing, for certain, that speciation actually occurs.


This passage contains a very serious misrepresentation of the link I provided to Tim. The author of the documents on the far end of my link does, indeed, indicate that the literature on speciation is poorly organized, but this does not mean that it is nonexistent. In point of fact, this one link provides over two dozen references to observed speciation events. A further source of references for speciation events is provided from the original link. In total, the issue is not that a literature on speciation does not exist, but rather that it is somewhat difficult to navigate. That many researchers assume that this literature exists (as it, in fact, does) is not unexpected given the immense utility of evolutionary theory to modern biology. One might as easily argue that gravity does not exist because most physicists are incapable of naming scientific articles that demonstrate that fact.

I must also take issue with Tim's remarks about inference. He claims, "...they [the scientists] go on information that has been inferred (rather than substantiated.)" However, what the author actually said was, "Third, the literature contains many instances where a speciation event has been inferred. The number and quality of these cases may be evidence enough to convince most workers that speciation does occur." In other words, the author is saying that we have such an abundance of inferential evidence for speciation, that most biologists are convinced. Since a literature demonstrating speciation also exists, this is not unreasonable. It's worth pointing out as well that "inference" is not the same thing as "guesswork." When a polieman stops a reckless driver and discovers that the individual in question can't walk a straight line, has slurred speech, and reeks of alcohol, the officer likely infers that the individual is drunk. Yet, however reasonable this assessment, the officer did not see the individual drinking alcohol. Would most people, then, say that the officer's conclusion is unsubstantiated? I think not. Inference is vastly more common, and respectable, than Tim's remarks might lead us to believe.

Moving on, we come to Tim's first objection to evolution:

For the purposes of the rest of this article I will use the term “species” with the Folk (or common)definition (again, from one of Dreks’ links). A. “reproductive compatibility and continuity. Dogs beget dogs, cats beget cats.” B. “You can tell species apart by looking at them.”

So, what is my problem with evolution? First of all, it does not fit with what we KNOW about species currently in existence. There are no “Dats”, “Cogs”, “Higs” or “Porses”. There are no feathered lizards, no scaly birds. There are not even wolves or cows with fins seeking to return to the water, or whales with feet or fingers sunning on the beach. In fact, a whale on the beach is considered so “unnatural” that we mount huge rescue efforts to get them back in the water. Are we actually hindering evolution?


First of all, Tim is employing a definition that combines two elements: reproductive continuity, and phenotypic distinction. I don't think this is an ideal definition but I'm willing to work with it for the time being, without conceding that it is the proper definition for the present situation.

Based on this definition, Tim then objects that we do not, at present, see combinations of species. In his words, "There are no 'Dats,' 'Cogs,' 'Higs,' or 'Porses.'" It seems to me that there are actually two objections embedded in this paragraph, which I will phrase as questions. The first is, "Why don't we constantly see new animals that are combinations of new traits?" The second question is, "Where are the transitional or intermediate forms between species?" I will deal with both questions now.

In the first place, the fact that animals do not routinely and suddenly alter their form is not a problem for evolution because evolution does not predict that they would. Certainly some evolutionary theorists talk about punctuated equilibrium in which change occurs relatively quickly but "relatively" in this case still means "tens of thousands of years." It is quick only by comparison to geologic time which is vastly longer than the span enjoyed by even the longest lived Human civilizations.

In more depth, evolution isn't just random, uncontrolled variation. It is, instead, often expressed as selection acting on the natural variation within a species, as well as on mutation, to produce new forms. Variation, in this case, refers to the diversity normal within a species- so if it is suddenly advantageous for a species to have a long neck, those individuals with long necks will survive more easily and reproduce more reliabily, passing on long necks to their progeny. Eventually, if long necks continue to be favored, we may see very long necks indeed. Mutation is, essentially, random change in the genetic code. As such, it introduces additional variation into the organism, and that variation is then acted upon by natural selection. An understanding of variation and selection is critical because the presence of selection pressures will tend to curtail the development of change that degrades an organism's fitness. As such, there are pressures both towards altered forms (when those forms enhance fitness) and away from altered forms (when those forms degrade fitness.)

Finally, it's important to keep in mind that organisms inhabit particular ecological niches. A niche is the role in an ecosphere that a particular animal exploits. Thus, two species can share the same land area if they exploit different food and shelter resoures- different niches. The concept of a niche also helps to explain why we don't see constant change. Let's imagine for a moment that it's the deep past and all animal life lives in the ocean. Plants have colonized the land but are, as yet, unmollested by predators. The oceans are home to many animal species and fierce competition for resources. Now imagine we have a browsing species that lives in the area right at the shoreline. This is helpful- the shallow water makes it more difficult for predators to reach this species- and so feeding is good. At the same time, members of this species compete with each other for food and mates, and enjoy some natural variation. Now let's imagine that some of these individuals are a little better at existing out of water than their counterparts. They can browse a little further up the beach, a little more out of water, taking advantage of the foliage on land. (This folliage might be as simple as algae, moss, or ferns.) These individuals are able to exploit a new food resource in a new area (essentially a new, or expanded, niche) that their fellows cannot. They will, similarly, do better and reproduce more successfully.

Over time these traits grow more common and this species begins to browse futher and further up the beach. This movement both removes the species from the water, where they are vulnerable to predators, and grants them access to new food resources. Gradually ungainly fins are replaced with structures that more and more resemble feet and legs. Evolution is occurring as a new species colonizes a niche. So far, however, we've only considered browsers, but what about predators? The browsers on the beach are a potential food source, so a predator that can get a little further up the beach has new sources of prey to feed on. So, those predators that have more endurance out of the water begin to breed more successfully, just as their counterparts among the browsers did. Eventually, we end up with both predators and prey that can spend most, if not all, of their time out of water.

Now, imagine what happens to another species of browsing fish that has members capable of spending more time on land- those members confront not just competition from the earlier-evolved species of browsers, but also may be eaten by the largely terrestrial predators. Unlike the earlier waves of colonizers there is little advantage to moving ashore because the available niches are already filled. What this boils down to is simple: speciation may happen readily when there are new niches to exploit, but may happen slowly, or not at all, when competition in a niche is already heavy. Moreover, the availability of niches depends in part of which other niches are exploited- there were no niches for predators on land until niches for prey had been filled. So, the absence of rapidly-evolving species (keeping in mind that "rapid" in evolutionary terms generally translates to "less than 100,000 years") is not particularly surprising in a world where most available niches are already occupied.

More fundamentally the issue here is not that I need to defend evolution, but that we should actually deal with what the theory of evolution predicts. Claiming that evolutuon is wrong because we don't see things that evolution wouldn't predict in the first place is to attack a straw man rather than the theory. This may be rhetorically impressive, but is logically nonsensical.

The second question, "Why don't we see transitional or intermediate forms?" is much simpler to answer. This is because we see many, many intermediate forms. We just don't usually recognize them as such. There is, for example, the lungfish which is a fish that can breathe and function for short periods on land. The lungfish, therefore, fits quite nicely into the category of an intermediate form, and nicely resembles the creatures in my above example. Lungfish are uncommon, but that's what we'd expect given the presence of other animals better adapted to the land, or the ocean, that can compete with them. For another example, consider the entire class of amphibians which are imperfectly adapted to life on land, even if they are far better adapted than the lungfish. You could consider amphibians as a class to be derived from a set of intermediate forms bridging between fish and reptiles. Then, of course, there is the flying squirrel which resembles rather nicely an intermediate form between more or less normal rodents and bats. It, additionally, takes little imagination to see that seals and sea lions resemble very much what modern day whales must have looked like in the past. And, of course, while Tim's comment may have been a joke, we have seen whales with vestigial, poorly-formed limbs and digits. Moreover we have examples of extinct whale species whose previous life on land is apparent from their skeletons and the continuing signs of that terrestrial life remain apparent in modern whale skeletons.

(As a side note: the movement of some mammals back into the ocean doesn't contradict the earlier discussion of niches. A large number of semi-aquatic mammals like otters have learned to exploit particular niches and marine mammals did the same.)

If we further open ourselves to fossil evidence, we find still more transitional forms. Modern birds appear to be derived from dinosaurs, and we have fossils ranging from the mostly bird-like Archaeopteryx to the much more reptilian Sinornithosaurus and the other feathered dinosaurs as support. Beyond this simple example, there are many additional examples of transitional or intermediate species in the fossil record.

Finally, if we want to consider artificial selection, I can think of at least two examples of speciation, one involving intermediate forms, that have been produced by humans. One example derives from a link I provided to Tim in my previous response. A speciation event was described as follows:

The Russian cytologist Karpchenko (1927, 1928) crossed the radish, Raphanus sativus, with the cabbage, Brassica oleracea. Despite the fact that the plants were in different genera, he got a sterile hybrid. Some unreduced gametes were formed in the hybrids. This allowed for the production of seed. Plants grown from the seeds were interfertile with each other. They were not interfertile with either parental species. Unfortunately the new plant (genus Raphanobrassica) had the foliage of a radish and the root of a cabbage.


A plant with the foliage of a radish and the root of a cabbage appears phenotypically distinct from both parent plants. Further, while it cannot breed with either parent plant, it can breed with others of its own type (Raphanobrassica). This meets both of Tim's requirements for a species and, so, we have a demonstrated speciation event that results in a blending of the features of two original parent species. This is not, however, an intermediate form.

For intermediate forms, I ask that you consider the Chihuahua and the wolfhound. Both are phenotypically distinct (speaking personally, I think they resemble each other less than an otter resembles a ferret.) and both are reproductively incompatible (if only mechanically) under all but the most unusual of conditions. Yet, both share a common intermediate or transitional form: the wolf. Certainly both dogs are genetically compatible, and can be exposed to each other's genomes via more closely related intermediates like terriers, but they meet Tim's criteria to be distinct species (Even if the BSC would consider them to be the same species), and have a living intermediary.

The point of all this is that intermediate and transitional forms are far from absent. These forms are, instead, abundant both in living and extinct species. The problem is that we don't usually think of an amphibian as an intermediate step between fish and reptiles- we just think of it as an amphibian. Yet, for all our failure to see them as such, these are examples to a greater or lesser degree of intermediate forms.

As for Tim's comment about the "unnaturalness" of whales on land, I will remind the reader that a century or two ago in the United States the idea of a woman wearing trousers was considered unnatural. Common judgments about such things are of dubious value. Additionally, I would say we certainly are interfering with evolution by helping these beached whales back into the water- but not because we're preventing them from growing legs. Rather, I suspect we're making beaching events more likely by saving the lives, and genes, of animals that are so inclined.

Having dealt with that objection, we come finally to Tim's stated attempt to demonstrate that evolution is not scientific. He makes this claim using four specific points, which I will address in order.

1. It is not Observable. Outside of the lab, no one has yet cited anything to me beyond “It’s all around us” or “It’s happening all the time”. Which tells me that most of you cannot think of one instance (that you can observe) of evolution in progress. We have been keeping records of descriptions of animals for at least a thousand years. No one can point to a significant difference between what they were then and what they are now. The only differences are adaptational (color, size, habitat, diet, etc.).


The problem here is determining what is meant by "observable." Tim seems to think that "observable" means we must see the thing itself in action. This would be one way to observe evolution, but not the only way. In fact, there are many elements of science that are not directly "observable." Atoms, for example, cannot be seen and, so, must be detected by their effects on other things. We know what these effects are because scientific theories make predicitions which can then be tested. If the prediction holds, then the theory is supported. On the other hand if the prediction fails, then the theory loses support and may be partially or fully falsified. By way of example, physicists and astronomers are confident that stars derive their power from nuclear fusion despite the fact that we have never "built" a star. Moreover, we can't directly observe the inner core of a star. The confidence of astronomers and physicists stems from a series of predictions made from theory that are substantiated by observational evidence- stars behave precisely as we would expect if they are powered by nuclear fusion. Additionally, while we can demonstrate nuclear fusion on Earth at a small scale, we cannot reproduce the scale of activity present in a star. Yet, despite our inability to directly observe something, we retain the ability to formulate and test theories about it. Given all this, to determine if evolution is observable, we must ask, "Does it make observable predictions about the world?" As it happens, the theory of evolution makes numerous observable predictions about the world. These predictions are described in vastly more detail than I can provide here. The document I provide a link to also includes a more detailed explanation of my above points:

Scientific theories are validated by empirical testing against physical observations. Theories are not judged simply by their logical compatibility with the available data. Independent empirical testability is the hallmark of science—in science, an explanation must not only be compatible with the observed data, it must also be testable. By "testable" we mean that the hypothesis makes predictions about what observable evidence would be consistent and what would be incompatible with the hypothesis. Simple compatibility, in itself, is insufficient as scientific evidence, because all physical observations are consistent with an infinite number of unscientific conjectures. Furthermore, a scientific explanation must make risky predictions— the predictions should be necessary if the theory is correct, and few other theories should make the same necessary predictions.

As a clear example of an untestable, unscientific, hypothesis that is perfectly consistent with empirical observations, consider solipsism. The so-called hypothesis of solipsism holds that all of reality is the product of your mind. What experiments could be performed, what observations could be made, that could demonstrate that solipsism is wrong? Even though it is logically consistent with the data, solipsism cannot be tested by independent researchers. Any and all evidence is consistent with solipsism. Solipsism is unscientific precisely because no possible evidence could stand in contradiction to its predictions. For those interested, a brief explication of the scientific method and scientific philosophy has been included, such as what is meant by "scientific evidence", "falsification", and "testability".

In the following list of evidences, 30 major predictions of the hypothesis of common descent are enumerated and discussed. Under each point is a demonstration of how the prediction fares against actual biological testing. Each point lists a few examples of evolutionary confirmations followed by potential falsifications. Since one fundamental concept generates all of these predictions, most of them are interrelated. So that the logic will be easy to follow, related predictions are grouped into five separate subdivisions. Each subdivision has a paragraph or two introducing the main idea that unites the various predictions in that section. There are many in-text references given for each point. As will be seen, universal common descent makes many specific predictions about what should and what should not be observed in the biological world, and it has fared very well against empirically-obtained observations from the past 140+ years of intense scientific investigation.

It must be stressed that this approach to demonstrating the scientific support for macroevolution is not a circular argument: the truth of macroevolution is not assumed a priori in this discussion. Simply put, the theory of universal common descent, combined with modern biological knowledge, is used to deduce predictions. These predictions are then compared to the real world in order see how the theory fares in light of the observable evidence. In every example, it is quite possible that the predictions could be contradicted by the empirical evidence. In fact, if universal common descent were not accurrate, it is highly probable that these predictions would fail. These empirically validated predictions present such strong evidence for common descent for precisely this reason. The few examples given for each prediction are meant to represent general trends. By no means do I purport to state all predictions or potential falsifications; there are many more out there for the inquiring soul to uncover.


The remainder of the first objection simply re-introduces the specious distinction between "adaptation" and "evolution," and complains that we haven't witnesses significant natural evolution in 1,000 years of record keeping. Given that, as discussed previously, the entire length of human civilization is not thought to be sufficient for us to witness extensive natural change, this is not a reasonable objection.

The second objection is as follows:

2. It is not Testable. Efforts have been made with yeast and flies. But neither has resulted in yeast or flies becoming something else. Yeast at the start, yeast at the end. Any differences seem to be only in compatibility with one another. Even after millions of evolutions. To truly test evolution, as stated by the staunch supporters of evolution, would require millions of years. By definition it is impossible for man to do so. (Quite convenient for the evolutionists, though. You can’t argue with something that so outdistances your own lifetime, eh?).


As indicated above, evolutionary theory makes numerous predictions that are susceptible to testing. Intermediate and transitional forms should exist, and they do. Traces of previous forms should exist in modern species, and they do. The testable, confirmable evidence of evolution is all readily available (and, as a side note, much of it is linked to in this post).

If there is a problem here, it is that there is too much emphasis on "seeing" the thing happen. Imagine for a moment that you are sitting on a jury for a murder trial. There are no witnesses to the murder, but witnesses did hear the defendant declare his intent to harm the victim. The victim was then found dead from a stab wound. When the defendant's home was searched, a knife with the victim's blood on the blade, and the defendant's fingerprints on the handle, was discovered. Moreover, the defendant lives alone and has no alibi for the time of death. Finally, spittle from the defendant was found in the victim's wounds. Now, nobody saw the murder take place, but the case that the defendant did, in fact, kill the victim is pretty strong. We have motive/intent, means, and opportunity, as well as supporting physical evidence. The situation is similar with evolution: we have motive (competition), intent (survival/reproduction), means (variation, selection, mutation), opportunity (geologic time), and ample physical evidence (genetics, fossil evidence). To say that the defendant can't have killed the victim simply because the police didn't arrive in time to see it happen is no more wise that claiming that evolution can't have happened because human scientists haven't been around watching for the past several million years.

Finally, the timespan over which evolution occurs does not make it untestable. As stated in my last response to Tim, we have tested evolution in the lab and have been able to cause speciation in fruit flys, plants, and bacteria. These creatures reproduce very rapidly and, so, can accumulate and express evolutionary change more rapidly. Longer-lived species cannot be tested in this way but, as stated, we have plentiful evidence for their change over time. Moreover, the fact that something takes place very quickly or very slowly doesn't make it untestable. The sciences of astronomy and geology both deal with processes that occur over extremely long periods of time, and both have enjoyed considerable success in predicting things. Moreover, we can't watch quantum mechanical processes occurring in real time, but we can still derive an understanding of them. Without such an understanding, modern microelectronics would be considerably less advanced.

The third objection is:

3. It is not Repeatable. In spite of their best efforts, scientists cannot make what they say happened happen again.


Absolutely incorrect. As stated above, evolutionary theory makes numerous predictions that have been supported over, and over again. We have found repeated indications of evolution, and have generated evolutionary change in the lab on multiple occasions. It's possible that what this objection means is, "scientists have not reproduced an entire planet full of advanced life forms identical to those on Earth," but this is a ludicrous condition. We haven't had the time or resources to try and, in any case, evolution would never predict the same species would emerge in the exact same way. Given the role of random mutation in evolution, even the same starting conditions could produce significantly different outcomes while using the same mechanisms. To demand we reproduce the Earth is akin to demanding that we reproduce the exact number and pattern of raindrops in a thunderstorm in order to claim that we understand weather. Just like astronomers and physicists have been able to show success in explaining star formation while being unable to "repeat" it, it is not necessary for us to "repeat" all of evolutionary history in order for observations to be repeatable.

Finally, the fourth objection:

4. It is not Falsifiable. If you can’t test it, you can’t repeat it. If you cannot do those things, you cannot set up an experiment to subject it to verification or refutation. By Poppers’ standard, you cannot prove that evolution is right, only that it may not be wrong. Which is a far cry from proof by anyone’s definition.


As explained above, evolution is observable, testable, and repeatable. Further, it makes predictions about the world that, if they are not true, call the theory into question. As such, it is most assuredly falsifiable.

In totality, the above indicates that evolutionary theory is, indeed, scientific.

There are several remaining objections that I will try to deal with quickly. The first is this:

Evolution suffers from another contradiction with science, in that it violates the 2nd Law of Thermodynamics. This, basically, observes that the universe is breaking down. Things go from order to disorder. A new car rusts. A rusty car does not become more solid, no matter what environment you place it in. However, evolution is defined as “A gradual process in which something changes into a different and usually more complex or better form.” Evolution is supposed to be a process through which single celled organisms became mutli-celled (more complex). It assumes that the stronger organisms survive (they are a better form). Yet we see that nature lends itself to a process whereby things break down, decay and die. Once dead, they revert to elemental forms (molecules, atoms, etc.). They do not get better, they get worse. Evolution is the scientific belief that the development of life is, as a whole, capable of defying the 2nd Law of Thermodynamics.


This objection, that evolution violates thermodynamic principles, is one of the most common from the anti-evolution camp, but it does nothing but demonstrate a profound lack of understanding of physics. The second law states that all work tends towards the production of greater entropy over time. This is often taken to mean, as Tim takes it to mean, that a system cannot increase in complexity. This interpretation is simply not correct. The expenditure of energy to do work always includes some amount of friction or inefficiency. This is why no human has ever succeeded in producing a perpetual-motion machine; since some of the energy added to the system is lost to inefficiency (entropy) the machine must, eventually, stop unless it receives additional energy from outside the system. This, however, brings us to an important scope condition: the second law applies to closed systems, but not to open systems. Thus, a system that is receiving new energy from outside can behave anti-entropically over time in a local sense (i.e. within the system) even though it's still part of a global increase in entropy. Without this scope condition not only would evolution be impossible, but life itself as well. Your body is an open system, deriving energy from food to continue operating and make repairs. If the second law prevented this from happening (i.e. if there was no distinction between open and closed systems), there would be no way for your body to continue powering itself. Your body heat would simply disperse your metabolic energy with no way to recover it, resulting in death. Just as a human being derives energy from food, the biosphere of the Earth- essentially our evolutionary "system"- derives energy from the sun. As that energy is added from an external source, the existence of life and the operation of evolution do not violate the second law of thermodynamics. A brief, but perhaps more lucid, response to the thermodynamics argument is also available here. Finally, as a side note, as I am not a physicist, I humbly invite any physicists in the audience to correct any mistakes in my explanation, or elaborate on any points.

Last, but not least, we come to a final objection:

But consider this, please. If I am wrong, I lose nothing. When I die I will return to my elemental form and feed worms. If you are wrong, you risk rejecting the Creator of all things. The price of that rejection is terrible. Not that He will send you to Hell. But that you send yourself there.


This objection more or less amounts to, "Disagree with me and you'll spend eternity in suffering." As threats have no place in a civilized debate, I don't think there's a great deal of value in this point. So long as we're discussing Pascal's Wager, however, I suppose we may as well do a good job. First, this argument is flawed simply on the face of it. If I were to do everything someone told me to do because of the unsubstantiated negative consequences of not doing so, I think I would be wearing a tin-foil hat right now. Second, even were I to accept your argument, I would be faced with the problem of determining which hypothetical deity to believe in. As there are a multitude of deities, many of which (we are told) will punish us for not believing, I'm in quite a fix. The only alternative to evolution is hardly belief in a Christian god. Finally, I think you are constructing a false dichotomy between religious belief and evolution. Quite a number of Christians, as well as people of other faiths, have no problem accepting evolution within the framework of a loving but inscrutable god. If the Lord does, indeed, work in mysterious ways, I see no reason to exclude evolutionary mechanisms from His mystery. Which takes us to my final point.

So long as we're throwing around quotes that don't really bear on the discussion, allow me to provide you with one from former President Jimmy Carter:

"...there can be no incompatibility between Christian faith and proven facts concerning geology, biology, and astronomy. There is no need to teach that stars can fall out of the sky and land on a flat earth in order to defend our religious faith."

In conclusion, while debate exists in science over the precise application of falsifiability, it is a well-established principle. The use of scientific theory and hypotheses is clear, and their distinction from assumptions is obvious. The observability, testabiliy, repeatability, and falisifiability of evolutionary theory have been established and, therefore, so has its status as a scientific theory. Arguments contradicting evolution on the basis of thermodynamics have been shown to rely on an inaccurate understanding of physics. Finally, the presence of abundant evidence for evolution is apparent, both in modern organisms and in the fossil record. In my view, the challenges offered to evolution have been answered, and I welcome any additional questions.

As a parting note, I wish to say two things. First, I have no interest in "converting" Tim to an evolutionary viewpoint. I respect his right to his religious beliefs and see no worthy purpose in attempting to force my perspective on him. I do, however, have every interest in countering misconceptions of evolution wherever they arise. Disagreement is fine, but disagree with the real theory, and argue against the real evidence- do not call a different theory by the name of evolution or ignore the evidence. Second, I have gone to considerable trouble to include a substantial number of links to information that supports, illustrates, or expands my points. In the event that Tim, or anyone else, chooses to respond, I ask that you do likewise. Unsupported rhetoric may be fun to read, but is ultimately of little value.

1 Comments:

Anonymous Anonymous said...

Everyone who does not accept Evolution as valid science will be condemned to heck for all eternity. (I use condemned to heck instead of another phrase to avoid language filters.)

I am deeply concerned with the growth of anti-evolutionism in the US today. It may be exaggerated because of the elections as candidates say things to cater to their 'base' but it is absolutely terrifying. The dangers of denying that evolution is science cannot be exaggerated. The people who deny it, like those who crucified Jesus, 'know not what they do'.

1) Let us look at the reasons why people deny that evolution is science.

The first and most common reason is that people are insulted to be told that they are related to monkeys. This shows up constantly in the literature of the anti-evolutionists. As in the title of the 'Scopes Monkey Trial'
http://www.law.umkc.edu/faculty/projects/ftrials/scopes/scopes.htm

When someone is insulted, their pride has been offended. Pride is one of the seven deadly sins.

"Listed in the same order used by both Pope Gregory the Great in the 6th Century AD, and later by Dante Alighieri in his epic poem The Divine Comedy, the seven deadly sins are as follows: Luxuria (extravagance, later lust), Gula (gluttony), Avaritia (greed), Acedia (sloth), Ira (wrath, more commonly known as anger), Invidia (envy), and Superbia (pride). Each of the seven deadly sins has an opposite among the corresponding seven holy virtues (sometimes also referred to as the contrary virtues). In parallel order to the sins they oppose, the seven holy virtues are chastity, abstinence, temperance, diligence, patience, kindness, and humility."
http://en.wikipedia.org/wiki/Seven_deadly_sins

"[edit] Proverbs 6:16 – 19
In Proverbs 6:16 – 19, it is stated that "(16) These six things doth the Lord hate: yea, seven are an abomination unto him:" (quotes from "King James Version (KJV)" translation of the Bible). These are:

(17) A proud look,
a lying tongue,
and hands that shed innocent blood,
(18) A heart that deviseth wicked imaginations,
feet that be swift in running to mischief,
(19) A false witness that speaketh lies,
and he that soweth discord among brethren."

"While there are seven of them, these sins are significantly different in outward appearance from the seven deadly sins list that arose later. The only sin which is clearly on both lists is Pride."

The only one of the seven mortal sins in the regular list found in proverbs is pride. The act of rejecting a scientific theory because of pride is a mortal sin, and all who are guilty of it will be condemned to heck for all eternity unless they repent in perfect contrition for their sins. You must be humble when you stand before the throne of God, and science, by examining the works of God in creating the universe is analyzing and describing the throne of God, Creation itself. To attack a scientific theory because it offends your pride is a mortal sin. Everyone who denies that evolution is science is in serious risk of eternal condemnation.

Now, a science completely independent of the theory of evolution has proven that we are related to Monkeys. Genetics and the typing of different genotypes has shown that we are indeed related to all other life on earth. Monkeys are our blood relatives, and that would remain a scientific fact if the 'theory of evolution' were proven false tomorrow.

So denying that we are related to monkeys because it offends your pride is a mortal sin, and the fact that we are related to monkeys has been proven to be a solid scientific fact by genetics independent of Evolution.

2) Evolution contradicts some peoples interpretation of the Bible.

Again this is the sin of pride. Priests and Ministers and religious authority are not immune to pride. They base their power and authority in the world on their skill and ability in interpreting their religious texts. When something contradicts their interpretation their pride is offended and they react on the basis of their vanity.

To deny that evolution is science because it offends your vanity by contradicting your interpretation of the Bible is a mortal sin, and unless you repent of it with perfect contrition you will suffer eternal condemnation.

There is no necessary conflict between evolution and the Bible.

" 24 And God said, "Let the land produce living creatures according to their kinds: livestock, creatures that move along the ground, and wild animals, each according to its kind." And it was so. 25 God made the wild animals according to their kinds, the livestock according to their kinds, and all the creatures that move along the ground according to their kinds. And God saw that it was good.

26 Then God said, "Let us make man in our image, in our likeness, and let them rule over the fish of the sea and the birds of the air, over the livestock, over all the earth, [b] and over all the creatures that move along the ground."

27 So God created man in his own image,
in the image of God he created him;
male and female he created them."

http://www.biblegateway.com/passage/?book_id=1&chapter=1&version=31

Here in Genesis in the first story of Creation, God created animals first and Man last.

"4 This is the account of the heavens and the earth when they were created.
When the LORD God made the earth and the heavens- 5 and no shrub of the field had yet appeared on the earth [b] and no plant of the field had yet sprung up, for the LORD God had not sent rain on the earth [c] and there was no man to work the ground, 6 but streams [d] came up from the earth and watered the whole surface of the ground- the LORD God formed the man The Hebrew for man (adam) sounds like and may be related to the Hebrew for ground (adamah) it is also the name Adam (see Gen. 2:20). from the dust of the ground and breathed into his nostrils the breath of life, and the man became a living being."

Here in Genesis in the second story of creation God creates Man first and then populates the world with other creatures. It is impossible for them both to be 'literal truth'. These two stories in the first few pages of the bible tell completely opposite stories of creation with regards to man. In one, Man is glorified as the last crowning creation of God. In the other Man is glorified as the first and most important of God's living creations.

It is impossible that these stories could be literally true. Evolution presents no more obstacle to Christian faith than the Bible itself does. There is no more of an automatic conflict between the Bible and Evolution than there is between the Bible and the Bible itself.

In the face of facts like these, when a Priest of Minister condemns Evolution because it conflicts with 'the literal truth' of the Bible, it is apparent that this is pride and vanity run amok.

Such men commit the sin of pride and then in their pride and vanity they mislead their followers into their own sin. Such sins will not be forgiven.

Again, these men will suffer eternal condemnation because of their pride and conceit.

3) In the cleverness of their pride and vanity, such leaders have decided that 'intelligent design' is science. On the contrary, the belief that 'intelligent design' is science is a trap laid by the devil to seduce men into sin.

Men are naturally given to vanity and pride. They define themselves as 'intelligent', Homo Sapiens they call themselves. Then when they talk about 'Intelligent Design' they define God as "Intelligent". So they say that they are the same as God. "Lo", they say, "We are like unto God, the Creator of the Universe. He may have more power than we possess, but our minds, our intelligence is the equal of his."

Is there a more clear example of sinful arrogance and pride than this? Is it possible to imagine a more terrible, mortal sin?

Indeed, this sin then leads them into terrible error. They say that since their minds are the equal of God's they do not need science to learn how God actually created the universe, they can sit in their drawing rooms and decide how he created the universe without reference to the facts.

There is a rather sad story about Einstein and Neils Bohr which illustrates this. Quantum mechanics offended Einstein's sense of an orderly universe.

He famously said, "God does not play dice with the Universe".

Neils Bohr another great physicist of the time replied, "You should not tell God what he can do with his dice."

This is the essential fallacy of intelligent design. It allows sinful man in his pride and arrogance to imagine that he is God, or the equal of God, and then to dictate to God how God should have created the Universe.

You must be Humble, when you stand before the Throne of God, even if you are Einstein, and Creation is the Throne of God, and Science is the study of Creation. You must, therefore, show humility as a Scientist, but a humility towards experimental facts and inductive reasoning to help discover empirical truth, not a humility before 'religious authorities'.

Intelligent design is a seductive trap created by Satan to seduce men into the sin of pride. Everyone who denies that Evolution is in serious danger of eternal condemnation.

4) Evolution is only a theory. This statement is widely made by the Evolutionists. It shows a profound ignorance of what Science is. Karl Popper a famous philosopher of science maintained "This problem arises from his position that the truth content of our theories, even the best of them, cannot be verified by scientific testing, but can only be falsified."
http://en.wikipedia.org/wiki/Karl_Popper

Popper is subtle, and a bit extreme. His standard of experimental falsification could be used to deny that astronomy, geology, and meteorology are not sciences because they cannot be tested in a laboratory but are only based on observations. People argueing on the basis of Popper's philosophy can get a bit silly. Still his point about all science being theories that can never be proven is essential to the understanding of science.

Every part of science is 'only a theory'. Gravity is 'only a theory', momentum is 'only a theory'. Yet, these theories serve us well. Frequently they are falsified by new evidence, but they remain true and reliable in the context in which they were originally formulated. Saying that Evolution is 'only a theory' says nothing at all. It only shows a vast ignorance of science and the philosophy of science.

When ignorant people try to dictate to scientists what is and is not science, they again commit the sin of pride. Again, people who do not accept Evolution as science are in danger of eternal condemnation.

5) Judge a tree by its Fruit. I did some searches for this, it is a well known quote from Jesus, but it did not come up on the Bible search engines I used. Searching the entire web showed that it is a quote from Euripides as well as from Jesus.

I did find the exact phrase that way.

Matthew 7:16-20, “You will know them by their fruits. Do men gather grapes from thorn bushes or figs from thistles? Even so, every good tree bears good fruit, but a bad tree bears bad fruit. A good tree cannot bear bad fruit, nor can a bad tree bear good fruit. Every tree that does not bear good fruit is cut down and thrown into the fire. Therefore by their fruits you will know them.”

This is essentially the scientific method. Theories are judged by their fruits. Their fruits are twofold. A good theory allows you to successfully predict outcomes. That, in turn, allows you to act successfully in applied science to make the world a safer, better place.

This being true, if Evolution is good science it should be bearing good fruit. So how is evolution helping us to make the world a better, safer place?

Let us look at medicine. It is fairly common today on the news to see news about new diseases which have evolved resistance to our traditional anti-biotics. If we did not know about evolution, we could not understand and successfully oppose these new diseases. Evolution tells us how this happens and allows us to counter it. It tells us that by carefully controlling the use of anti-biotics we can prevent their use in circumstances which would allow bacteria to evolve resistance to them. This helps us keep drugs effective in fighting disease longer. It also tells us that we need to develop new drugs to counter the effects of evolution. The 'Theory' of evolution is actively saving the lives of our fellow human beings every day.

I do not know of a single life which has been saved by creationism or intelligent design. On the contrary, creationism and intelligent design will kill people.

A doctor who is a Creationist knows that evolution is false, therefore, disease cannot evolve resistance to penicillin. In treating his patients he will continue to use penicillin instead of the new drugs, and his patients will die. Then, on judgement day, standing before the Jesus, the King of Kings, the people he killed will accuse him of their deaths. What will his defense be? Will he plead that his pride was offended because evolution said he was related to monkeys? Will that justify murder on the day of final judgement. Will he say that his minister taught him that evolution was false and he trusted his minister more than he trusted scientists?

Failure to accept evolution as science places people in severe danger of eternal condemnation.

The above example will not happen often today. The anti-evolutionists today accept that bacteria evolve, or they find some other way to accept medical truths. Still, if we had stopped teaching evolution as science in 1925, then it would be happening today. Thousands, possibly millions of people would be dying of disease because we did not accept evolution as science.

I do not know what horrors await humanity in the future because of creationism and intelligent design. I only know that judging by their fruits, if they are taught as science, it will lead to the deaths of millions, and the waste of billions of dollars in scientific research based on theories which are not science.

When you murder millions of people because your pride is offended by evolution, you are committing a mortal sin. Everyone who fails to accept evolution as science is in serious danger of eternal condemnation.

A few more demonstrations of the good fruits which evolution is producing in the world today.

http://www.talkorigins.org/faqs/genalg/genalg.html

"Creationists occasionally charge that evolution is useless as a scientific theory because it produces no practical benefits and has no relevance to daily life. However, the evidence of biology alone shows that this claim is untrue. There are numerous natural phenomena for which evolution gives us a sound theoretical underpinning. To name just one, the observed development of resistance - to insecticides in crop pests, to antibiotics in bacteria, to chemotherapy in cancer cells, and to anti-retroviral drugs in viruses such as HIV - is a straightforward consequence of the laws of mutation and selection, and understanding these principles has helped us to craft strategies for dealing with these harmful organisms. The evolutionary postulate of common descent has aided the development of new medical drugs and techniques by giving researchers a good idea of which organisms they should experiment on to obtain results that are most likely to be relevant to humans."

http://en.wikipedia.org/wiki/Genetic_algorithm
http://geneticalgorithms.ai-depot.com/Tutorial/Overview.html

If we judge trees by their fruits as Jesus commanded, we must accept Evolution as science, and reject Creationism and Intelligent Design.

Thursday, November 15, 2007 3:49:00 AM  

Post a Comment

<< Home

Site Meter