I have been hearing these comments many times lately. For the most part I have heard them from fundajelical Christians who claim microevolution happens while there is no possible way macroevolution could happen. Also for some reason they continue to call the modern theory of evolution Darwinism as if there have been no advances in the theory and it was finalized by Darwin in 1859. It is also interesting to notice that fundajelicals often call evolutionary theory Darwinism as if they are saying “yes, we have an irrational belief in a religion but you have an ‘ism’ too.” The saddest part is that I have heard these same three statements made by a self-proclaimed agnostic that believes in an intelligent creator (which means he is a theist not an agnostic). Since these mistaken beliefs are apparently so widespread, I figured writing an article addressing them would be a very good idea.The first misconception, well not exactly a misconception, is calling the modern theory of evolution Darwinism. Evolution was first written about in a poem (On Nature) by a 6th century BCE Ionian philosopher named Anaximander. In the following centuries (5th and 4th centuries BCE) we find Xenophanes, Herodotus and Hippocrates examining and collecting fossils. As a matter of fact Xenophanes taught that the world formed from the condensation of water and primordial mud, he was the first person known to use fossils as evidence for a theory of Earth history. Yet in spite of all this, the modern theory of evolution is condescendingly called Darwinism (instead of Anaximanderism or Xenophaneism) by those that misunderstand the theory (I will try to explain the theory a little later). Also as I mentioned earlier, calling the modern theory of evolution Darwinism is almost as if a fundajelical is admitting they are irrational in their faith but claiming we have faith (an ism) also. To be fair I must mention that certain evolutionary biologists and paleontologists call the modern theory of evolution Darwinism at times but they neither do so in a condescending manner, they are not belittling the theory, they understand the theory and they are not foolish enough to think the modern theory of evolution is the same as it was when Darwin wrote On The Origin Of Species in 1859.
The microevolution versus macroevolution distinction made by people that deny evolution is in my opinion nothing more than a tacit admission that they do not understand the modern theory of evolution because either they have not been taught it or they are approaching it from a preconceived bias generally based on a fundajelical belief in the creation as found in Genesis. A fundajelical definition of micro and macroevolution is as follows (from Prayson Daniel)
Macro-evolution – Refers to the emergence of major innovations or the unguided development of new structures(like wings) new organs(like lungs), and body plans(like the origin of insects and birds). It includes changes above the species level.
Micro-evolution – Refers to minor variations that occur in populations over time. Examples include variation in moth coloration and finch beaks, and the emergence of different breeds of dogs.
As is quite clear from the above, the modern theory of evolution is not understood. Earlier i said I would attempt to explain it so please bear with me as I try to do so. The theory of evolution has six different components. They are
4. Common ancestry
5. Natural selection
6. Nonselective mechanisms for evolutionary change.
For the most part these component parts are connected to each other but one in particular is independent of the others and that is gradualism (natural selection is somewhat independent too). At times, evolution does happen quite fast and can even be seen in a laboratory. In general though, evolution is gradual.
Right about now some of you are probably thinking “great he takes evolution which is one thing to misunderstand and transforms it into six things to misunderstand.” Ok, you are right so I will explain each point in detail (and it will be short, happy now?).
Point 1 is evolution. Simply put that just means change over time. Since this is about biological evolution, more specifically it means genetic changes over time. This point can’t be denied by anyone unless to say it as Jerry Coyne did, they have an extremely perverse mind. Even the fundajelical microevolution idea admits evolution happens (guess they aren’t as perverse as we think).
Point 2 is gradualism. Evolution, meaning the change or specifically the genetic change happens and generally it happens gradually. That is not to say all species evolve at the same rate. Some bacteria evolve extremely fast (hence the rise of things like MRSA, VRSA and many other drug-resistant bacteria) while there are creatures like the “cuddly” coleacanth which is not called the living fossil because of it’s speed of evolutionary change. At times evolutionary changes can happen very quickly but that in no way claims that evolutionary change is not gradual. Major evolutionary change generally takes thousands if not millions of generations.
Point 3 is my favorite along with it’s inverse in point 4. Those are speciation and common ancestry. First I would like to mention that if speciation didn’t happen, we wouldn’t have the evolutionary tree nor any of the diagrams we are all familiar with, we would have a vine. Speciation, which a fundajelical would consider impossible macroevolution, is nothing more than undeniable evolutionary changes (point 1) adding up over time (point 2) eventually leading to speciation (point 3 – evolution, as easy as counting to 3). Some deniers of speciation may question how the “split” causing speciation is made but that answer will be discussed under point 5 natural selection so until then, please sit on your hands and continue reading. Some claim speciation has never been seen but that is a claim made only by those who have never read or studied evolutionary theory. One undeniable example is polyploid speciation which is seen comparatively often. One estimate is that between 30 and 80% of plant species are due to polyploid speciation. Although polyploid is very rare in humans, it occurs with some frequency in animals such as flatworms, brine shrimp and leeches. Generally polyploid animals are sterile so they reproduce by parthenogenesis. A quite common polyploid animal species are some lizards and they are parthenogenic wich leads me to the really odd mole salamander who are all female and reproduce by kleptogenesis. That is they “steal” spermatophores from a related species (from the males of course) just to trigger the egg’s development but not to utilize any of it’s DNA. More examples of speciation can be found on talkorigins website here and here. A few examples of speciation (Allopatric or geographic) would be seen at Madagascar and more recently at the Isthmus of Panama. Due to the mechanics of fossilization, speciation is not seen as clearly and as often in the fossil record as would be liked but there is one well known and undeniable example to be found with diatoms. A little about diatoms can be read about here.
Point 5 is natural selection and in it is the main objection most evolution deniers have. First and easiest way to describe natural selection is to compare it with something well known and the results of with are seen everyday (even with the atheist’s nightmare which Ray Comfort and his cohort Kirk “Mike Seaver” Cameron say is the banana which they didn’t know was made through artificial selection) and that is artificial selection. In artificial selection the gene pool is selected for desired traits such as color or fragrance (in flowers), height, weight, temperament (in dogs) and color, fragrance, edibility (in food crops). Natural selection is the same process but instead of a conscious individual doing the selecting it is done by natural circumstances. At times the selection is made by environmental constraints such as availability of food, climate and geography (as in allopatric speciation). When a species is separated for any reason (such as geography) the evolutionary changes both populations accrue will not necessarily be in the same direction. Eventually either for physical incompatibilities or just to many differences in their DNA, they will not be able to reproduce with one another and another species is born. Oh, those of you who deny speciation, please reread that sentence a few times and let it sink in.
Point 6 is nonselective mechanisms for evolutionary change. It isn’t really necessary to delve into this last point with any detail. Just as there are selective mechanisms (as in natural or even artificial selection) there are nonselective mechanisms such as genetic drift and the randomness in frequency of offspring (I have one child, you have two, my great grandmother was one of 26). Generally the nonselective mechanisms do not have a large influence on evolutionary changes but they do have an influence so they must be included in the theory of evolution.
In conclusion, the modern theory of evolution contains six components (1. Evolution 2. Gradualism 3. Speciation 4. Common ancestry 5. Natural selection 6. Nonselective mechanisms for evolutionary change) that really can’t be denied. To be honest, it is understandable how someone unfamiliar with the entire theory can question points 3 (4 comes along for the ride) and 5 but after familiarizing oneself with the modern theory, the questions fade away unless one really is blinded by a theological cloud (read that as fundajelical Christian). Of the 6 points of the theory, some are intimately connected such as my favorites points 3 and 4 (speciation and common ancestry) while some are independent of the others such as gradualism (which at times is extremely fast) and in some respects natural selection. Meaning even if gradualism or natural selection were false, evolutionary theory would still be true it would just need to be redefined. Since natural selection was considered independent from the theory of evolution, that is pretty much the reason biologists of Darwin’s time were so quick to accept evolutionary theory but not natural selection. Considering all the advancements made since Darwin’s time, natural selection is still pretty much independent of the other 5 points of evolutionary theory but it is not questioned by any serious academic that understands the theory (William Craig Lane, Michael Behe, Kent Hovind and the rest of the idiot crew are not academics).
Filed under: Biology, Creationism, Evolution, Genetics, Paleontology, Science | Tagged: Biology, Charles Darwin, Darwinism, Evolution, Isthmus of Panama, Jerry Coyne, Macroevolution, Origin of Species |