Evolution: What is it? (long article)

Evolution; it's a word that invokes thought and emotion. It makes you think about our origins, about the manner in which scientific material is collected, and the way in which it is interpreted and presented. No matter who you are, the word reaches you at some level emotionally; whether it is the search for our origins, understanding the world around us, a heresy, or a concept that no-one's really been able to master. It describes what's happening now, it describes what's happened in the past. It tries to explain how systems change with time and how we got here. It looks for an underlying mechanism behind unexpected events with unexpected results. Few words really encompass so much in their definitions. The word pertains to the source of all life, the paths life takes and has taken, and the way complex systems become inherently different over time. How can one really write any one definitive thing about this word? You simply can't, and so you must break it down-redefine it.

What are we going to talk about now? We are going to talk about evolution of biologic systems. We are going to delve into the heat of the debate, and try to clarify the murky waters of science for both sides. As is often the case, perhaps the truth lies somewhere in between...

And so the question arises, just what is biologic evolution? The answer is that even this subcategory has several popular definitions. It is a change in the genetic or physical characteristics of a population with time. By far, this is the best definition. Other, more commonly used definitions, are: "the arisal of one species from another" and "the arisal of life from a single group of animals (or life)." The first definition is 100% true and factual. It is easy to understand that the genetic characteristics of a population can change. Just look at a few of the classic examples:

It's kind of ironic to think that no-one was looking for the birds to evolve. In fact, Peter Boag thought the occurrences leading to the rapid-evolution event were the worst things that could possibly happen to him.

Peter and Rosemary Grant had been studying Daphne Major since 1973. Like most other researchers in the area, they came during the wet seasons to study the finches. They looked at the ground finches and studied what they were eating very meticulously by making observations during feeding. They measured the weight and beak size of the finches, catching as many as possible (which was most of them). They then sifted through plots of ground to count all of the seeds that were available as food and compared them to what the birds were eating. The two dozen species of seeds were measured for size and hardness, which were then combined into a "struggle index" so that the Grants could see how difficult the seeds were for the birds to eat. The birds were all eating the same seeds and so there didn't seem to be any real reason for the variation between the 6 different species of ground finch. This was during the wet season, however, when food is plentiful. When the Grants came back a few months later, the research station reported that there had been no rain at all for the months of April, May, June, and July. The Grants did the same thing they had done a few months earlier and found that the finches had lost weight and that most of their food was gone (84%). Before, the average seed was a 0.5 on the struggle index. Now it ranked a 6, 12 times more difficult than before.

Magnirostris has the largest and most powerful beak; strong enough to tear the metal ID bands from their ankles.

Now that food was much more scarce, Magnirostris was focussing more on the large, hard seeds that none of the other birds could crush. The cactus finch was putting it's beak to use by dining on cactus seeds. In fact, all of the birds were now using their specialized beaks and sizes to help them make it through the tough times. There's a universal biological concept, and that is: unless food is extraordinarily plentiful, no two species will live on the same menu. This is because the two species will compete. One will adapt to either become better at getting the food than the other species, or it will find another food to eat. The same will be true for the other species until either one has become extinct or they eat two different types of food. Now all of the birds were filling their little niches so that competition with other species was lower and their chance of survival was higher.

Think of it like this (a hypothetical situation): two species of deer like to eat the same berries. The deer increase in number and the berries are becoming fewer since they are all being eaten. Now, they have to get better at eating the berries in order to keep getting them (or else they will starve), so they evolve. Perhaps one species becomes smaller so that it doesn't have to eat as many berries and can reach around the bush easier. The other's face narrows so that it can stick it's head through the brush more easily. Whichever change was more successful will result in that animal getting the berries while the other won't. The only option left for the loser is to start eating something else and it will become adapted to eating that other thing (say it develops a longer neck and legs for eating leaves). So you see that the deer now feed on two different types of food. If the less successful species of deer had not changed it's food source, it would have become extinct because it was not able to get enough berries. This is an important biological concept to understand. This won't occur, however, if food is plentiful.

It is also necessary to understand how the process of this kind of evolution occurs. Let's continue with our hypothetical deer/berry situation. As I mentioned above, in our imaginary scenario, one species of deer becomes smaller and the other develops a narrower face. These events don't occur during the life of a single deer, however. Let's look at the species that got smaller. Since the berries were scarce, the deer were beginning to go hungry. As a result, the largest deer (which had to eat the most to survive) starved to death. On the other end of the spectrum the smaller deer didn't have to eat as much and they could get to it more easily than the big deer. Moreover, the larger surviving deer might be too weak to reproduce successfully. All of this combined will mean that the resulting generations will be smaller (small deer tend to produce small deer). The species has thus evolved (refer back to the definition of evolution).

We see a reduction in size here, but the other species of deer actually had a refining of features going on. How does this happen? Well, you might be surprised to find out that it's quite similar to the other instance. The deer with narrower faces can fit their heads through the brush more easily to get those hard-to-reach berries. That means that they'll be eating more than the wider-faced deer, which are dying out due to starvation (its the same situation as seen above). With wide-faced deer being cut out of the gene pool, subsequent generations are then narrower-faced. (note that physical traits are generally passed on genetically)

Competition will continue between the two species, as each gets better at getting the berries, until one finally dies out due to starvation (it couldn't compete) or changes it's food source. If the species does change it's food source, it will evolve to fit it's new diet (not unlike the above cases).

Similarly, the above scenario can cause two species to split. Imagine that the two species of deer were actually a single species now, where individual animals had to compete with each other for the same berries. The best equipped animals in that species will survive the best, and those that can't compete either die out or get a new food source. If they pick a new food source, they will form separate herds from the other animals and reproductive isolation will occur. (I'll explain that a bit later)

And so the finches on Daphne Major were filling their niches and eating the specialized food they needed to survive. In fact, the species had become so specialized to their specific location that each species on the island differed in size and dimension from other birds of their species on other islands (although the difference are usually small).

Another important thing to note is that tiny variations in structures can have huge benefits. Fortis birds on the island of Pinta have slightly deeper beaks than those on Daphne Major. It can take over 6 minutes for a Daphne Fortis to crack open a torchwood stone and most end up giving up. On the other hand, four out of five Pinta Fortis can crack open torchwood stones. The stones are identical on either island, but Pinta Fortis' beak is one millimeter deeper (average).

On Genovesa, Cactus finches diversified their food sources within the species even. Birds with very long beaks pick at the fruit and flowers on cactus. Ones with long and deep beaks can eat the seeds off of the cactus. Birds with very deep beaks rip the bark of trees and eat the bugs underneath. When food is plentiful, however, they all eat the exact same stuff.

Enter Peter Boag. The poor man just wanted a simple little experiment for his thesis. He saw that the traits of the parents were passed down through the young, but no one had ever studied how! No one was really sure if the traits were genetic or due to the environment. For example, did birds with large beaks pass on that trait genetically, or did parents with big beaks bring back more food which caused their young to grow big beaks? Well, he wanted to figure that out for beaks and body size, so this is what he planned to do: he was going to take eggs out of the nests and switch them around. He wanted to take eggs from big beaked parents and give them to little beaked parents to see how they grew and developed. He wanted a whole host of egg switchings between nests and families of different beak sizes and body sizes, but he couldn't do it during the dry season. Finches don't mate during the dry season because food and water are scarce and the young are almost guaranteed to die. All he needed was the wet season. All he needed was rain.

He never got it. (A later study on Mandarte Island by Jamie Smith showed that such variations in sparrows were genetic)

Instead he got a vicious drought when the rain season just didn't come in 1977. The amount of food available plummeted. In June 1976 ( a normal dry season) there were 10 grams of food per square meter (which, if you'll recall, created a great deal of competition). June 1977 there were 6 grams. By December there were 3. There were 1400 finches in March 1976. There were fewer than 300 by December 1977. The drought also wiped out the younger generations of birds so that only the old ones were left. Conditions were extreme.

On Daphne Major there is a plant called tribulus that produces caltrop fruit. The fruit is actually composed of a number of spiny pieces called mericarp. The mericarps are vicious-looking, tough shells that contain about 3 to 6 seeds apiece. As you could imagine, caltrops aren't a favorite food of finches, but magnirostris and fortis can eat it. Magnirostris, with a beak twice as wide and deep as fortis, clamps the mericarp in it's beak until it eventually shatters, after which the pieces are picked up and crushed. This requires about 200 newtons of force (to eat a whole caltrop), but fortis can't handle that, so instead it pins the mericarp to the ground and bites and twists the shell off of the seeds. Because this takes so long, fortis can rarely get to all of the seeds. Does the extra time fortis takes means it is less successful than magnirostris? No, because it has a smaller body mass and doesn't have to eat as much as the other.

So how does tribulus protect itself from the finches (figuratively)? Well, the finches go for the attractive looking mericarps that have few spines and have a lot of seeds in them. Since these traits in tribulus are passed on genetically, few of this kind of mericarp survive to produce plants. The passed over mericarps (the ones with a lot of spines and few seeds inside) are the ones that survive to reproduce, which means that the finches have forced the tribulus to evolve. How do we know the tribulus has evolved, though? Well, Peter Grant compared caltrops from the crater rim where there are a large number of the predatory finches to the inner crater wall where there are few finches. Where there aren't finches on the island, caltrops have fewer spines and more seeds per mericarp. This makes sense because it doesn't have to focus on defense and the mericarps with most seeds are the ones most likely to survive and reproduce.

Competition during the drought was fierce (they had witnessed 30 gram birds knocking over 400 gram rocks looking for food, which is like you knocking over a 1 ton truck for a chicken nugget). During wet years, birds rarely ate mericarps, but now it was a staple for fortis and magnirostris. The smallest fortis who couldn't handle the caltrops looked for the small soft seeds under the Chamaesyce bushes. Broken stems and leaves, however, leak a sticky, milky goo that got on the birds heads. When the birds would rub their heads in the gravel, trying to stir up some food, the feathers on top of their heads would rub off and as their bald scalps were exposed to the beating sun, they would die. The weight of the birds had dropped by 25% and most hadn't molted in quite some time resulting in the inability to fly. The birds were desperate for food. Whenever a blue-footed boobie would drop a fish, it would soon be covered by feeding finches. Some took to eating broken eggs and guano. One finch started eating lizards and another was seen drinking the blood of another wounded bird.

When Boag came back in January of '78 (after the rain had returned), they found only 200 finches meaning that 86% of the population had died. After performing measurements on the remaining population of fortis, they found that the average length of the beak had grown by 4% and the deepness had grown by 5% (which is a whole lot for a single year. Also, note that there was no growth in the individual birds, but rather smaller-beaked birds died shifting the average.). That's quite a bit when you consider that the difference between a beak that can break caltrops and one that can't is a half-millimeter. In addition to this, since males are usually about 5% bigger than females, with that much larger beaks, a lot more males survived than females, making the male to female ratio there very similar to what it is at Michigan Tech. About 6:1. Finches, being monogamous, breed as couples, and yet there was not one couple left on the island (at least one from each couple had died) so they got to watch sexual selection in action as all the females looked for mates among the competing males. As the researchers watched the selecting, they found that the largest of the remaining males were chosen by the females.

Now, since size is heritable and the smallest birds died during the drought and the smaller of the remaining large birds were not able to breed, what should happen to the population? The new generation of birds had beaks, on average, 4-5% deeper than the remaining population. In fact, the new birds were larger in just about every way, but growth in the length and width of the beaks was not advantageous and did not occur during the drought. This shows that the birds did not just become bigger, but actually changed their bodily dimensions as well. To throw another twist in the story, young birds with smaller beaks survived the drought better than young birds with big beaks. That's because, no matter how big, juveniles aren't strong enough to break caltrops so they have to forage for soft seeds. The larger birds had to eat more, but with food so scarce they couldn't and they would die. Smaller birds were able to survive on less food, though.

They weren't there to study evolution either. In fact, the whole basis for the experiment was that adaptation would not occur. Oops. Anolis lizards were taken from Staniel Cay (by Jonathan Losos) in the Bahamas and placed on 14 smaller surrounding islands that didn't have any lizards in 1977 and 1981 (5-10 lizards were placed on each with a 2:3 male:female ratio). The idea was to study extinction in the lizards. Some islands were pretty much bare rock with less than a square meter of vegetation and about the area of a football field, while others contained up to 6000 sq meters of vegetation. The lizards on some islands, indeed, died quickly, but on other islands they became quite successful. In fact, on one island there are now over 700 lizards! The lizards adapted, not by changing in size, but by changing the dimensions of their legs so that they could hold on to the narrow brushy vegetation better (ie, narrower legs meant better chances of survival and increased competition).

On other islands in the Greater Antilles, we see convergent evolution. Anolis lizards on the major islands were observed and there were several types of lizards on each one, each one filling a specific niche. These were classified as ecomorphs, and they were the following: Crown-giants (large lizards in the crown of trees), Grass-bush, Trunk, Trunk-crown (lived on both the trunk and crown of trees), Trunk-ground (lived on both trunks and ground), and Twig. Interestingly enough, mitochondrial studies of the lizards have revealed that the ecomorphs of a single island are more closely related to each other than similar ecomorphs on other islands (this means that morphologically [physically] different lizards were more closely related to each other than they were to morphologically similar lizards on other islands). This has major implications as it shows that when animals (namely the lizards), separated and even different species, fill similar niches they evolve in the same way as a result; that is, their bodies adapt to the environment similarly. Even more interesting is the fact that there is no clear relationship between the arisal of ecomorphs. The studies show that in Puerto Rico, Trunk-crown lizards evolved from Trunk-ground, while in Jamaica Trunk-crown lizards evolved from Crown-giants (recall that animals change physically to new environments).

Of all the things that pop into your mind when you hear the word "evolution," "guppies" probably isn't one of them. Unless, of course, you're John Endler. When we speak of guppies here, we aren't talking about stuff in the pet store, but rather beautiful, colored guppies from the streams of South America. The male guppies wear spots that are colored black, red, yellow, green, blue, iridescent, and which vary in size, brightness, and combination. The gravel in the stream beds in these areas is multicolored, like the stuff in some people's fish tanks. The spots on the fish serve as camouflage to protect them against their seven enemies: six species of fish and a prawn. The streams have waterfalls dividing them into sections, and obviously neither predator nor prey can make it up these, so you get an interesting situation. Generally, at the top of the stream, near the source, there is only one predator (which is Rivulus hartii and is the least dangerous of all 7 predators), and as you move further downstream the number increases until you reach the bottom where you have them all.

Endler began catching the guppies, recording observations, and releasing them back to their environments. He found that guppies downstream had spots that were generally duller while the ones upstream had much brighter spots (especially near the source). Spots on guppies that were heavily predated were also smaller. Upstream fish wear big blotches of iridescent blue while down stream fish wear tiny dots of black and red. Why was it like this? Well, big gaudy spots attract the ladies, but they also attract predators. In heavily predated streams, gaudy fish might be popular with the ladies, but they'll probably get eaten before they have a chance to reproduce, so the gaudy fish die out. This means that the dull-colored fish don't attract as many females, but they have a longer life to reproduce so they'll be successful anyway. Upstream, however, where there is almost no predation, you just gotta strut your stuff. Without having to worry about predators, the fish have big clown-like stripes to advertise to women and they'll probably live as long as the dull colored fish. That means that the brightly colored fish will be much more successful than the dull colored ones. It becomes even more obvious that colors reflect predation when you look at guppies in prawn-infested waters. They are covered more in red because prawns are red-blind and females aren't.

It all looked good, but Endler had to test it to find out for sure. He built ten ponds in a greenhouse in Princeton and filled them with multicolored gravel and placed a current through them. He then collected guppies from Trinidad and Venezuela from a dozen streams and from all types of predation. He took the guppies and randomly placed them in the ponds and let them breed for months. Then he started placing predators in the ponds. His results? The same thing he saw in S. America.

That's great, but it was an artificial environment and Endler wanted to make sure he was completely right and that no one could invalidate his work so he found two streams in Trinidad 2 km apart. One had guppies and a host of predators and the other had no guppies and only the Rivulus hartii. Endler took 200 random guppies from the predated stream (they were dull, of course) and put them in the guppy-less stream. Fifteen generations later, he returned to make observations on his fish. The ancestors of the dull fish he had moved were now much more gaudy than before.

What happens when seeds from a large land-mass get blown onto a small island? Well, for that we look to Asterace on the small islands just outside British Colombia. The seeds were blown by the wind onto the islands, where they took root as weeds. The interesting thing to think about, however, is that the seeds that got to the island had to be carried a large distance, and so had a large pappus (parachute-like structure) to be carried efficiently by the wind. This is a genetic trait, however, and the weeds were on a small island.

The plants produced seeds with large pappae, though there was some variation in size (as there always is-think about it, are you the exact same size as your parents? Most people aren't, though they are of similar size). Most of the seeds were blown out to sea, but some of the smaller ones landed on the island and survived. The result was that the plants there produce seeds with a smaller pappus, but a larger embryonic section to weight it down and keep it from being carried too far by the wind (similar situation as Tribuls).

There's a type of mosquito in England called Culex pipiens that feeds on birds, but doesn't bite much else. About a 100 years ago, the mosquitoes entered the tunnels being dug for the London Underground. The only problem for the mosquitoes now living in the tubes is that there don't tend to be many birds underground, and so they took to feeding on rats and humans (which may be why they were dubbed molestus). The new variety was named Culex molestus and it has been found that it is pretty much impossible to mate molestus with pipiens now.

Species are defined as clades of animals that interbreed and are both genetically and anatomically similar. The key word in our use of species here is "interbreed." Since the pipiens and molestus mosquitoes could no longer interbreed, that makes molestus a completely different species from pipiens. This definition of species isn't always very clear, for example, have you ever heard of any of these animals: Liger (lion and tiger, also known as tigon), Wholfon ( psuedo-orca and bottle nose dolphin), Zonkey (zebra and donkey) and Zorse (zebra and horse), Cama (camel and llama), and Chimera (goat and sheep). Still, the species definition is good and applies for the vast majority of cases. The ability to interbreed does not necessarily make them the same species, but not being able to interbreed automatically makes them different species.

The arisal of a new species from another is known as speciation. Speciation usually occurs through reproductive isolation. Reproductive isolation occurs when a group of organisms gets separated from the rest of it's species. After years of reproducing without any genetic mixing going on between the two groups, one will usually not be able to breed with the other either due to behavior or biologic restrictions.

Ok, so let's look at two species of wasp; Nasonia giraulti and longicornis. Being two different species, they can't interbreed, but both are infected with a type of bacteria known as wolbachia. Wolbachia is a cytosplasmically inherited bacteria that screws with reproduction. Even using artificial means, you can't get a hybrid Nasonia wasp, but if you first treat the wasps with antibacterial drugs to kill the wolbachia, they can suddenly produce hybrid offspring. This shows that the only thing making them biologically incompatible (behavior also works against natural breeding) is the bacteria, suggesting that the introduction of bacteria to the species may have resulted in the speciation long ago, though it is not known for sure.

So now you've gotten a taste of some of the evidence for evolution-the change in the genetic make-up of a population. You can see that evolution can cause features to be modified and that new species can even come about! So the "evolutionists" are right, right? I mean, if everything about the theory works, who's to say they aren't correct? We are. "Evolutionists" believe in something I like to refer to as "Ex nihilo" evolution or as "common descent from a single clade." It's a fact that common descent can be seen in nature-the molestus mosquitoes descended from pipiens and a whole host of experiments with fruit flies and bacteria give even better examples. But when informed creationists argue against evolution, it's not against biological evolution in the standard sense, but "De unum evolution" (my pet name for "common descent from a single clade") or "Million-year evolution." That is the idea that all of life on earth today descended from a single species, or even a couple, billions of years ago. If biologic evolution is a solid rock of science, de unum evolution is swiss cheese; weak and full of holes. MY-evolution (to be pronounced "Million Year evolution" rather than "my evolution") is dependent upon observations made from the fossil record and inferences upon what happened during periods in which no fossils of that specific clade were deposited.

As an example of MY-evolution, let's look at the origin of birds. Evolutionists have been looking for the origin of birds for years, and have turned to dinosaurs. They compare the anatomy of therapod dinosaurs to birds, look for "proto-feathers," and jump on every fossil find they get. Every time there is a new "bird-like" fossil discovery, it rocks the field and causes a huge commotion. Old ideas are fitted to the fossil, and thrown out the door. New ideas arise, only to become passe just months after they arose. Few hypotheses and theories regarding therapod-avian evolution survive more than a few subsequent discoveries.

Here's a case of fact applied to theory that's gone horribly wrong (convergent evolution). Let's look at a quick excerpt from another article of mine:

There are two main types of bats: microbats and megabats. Microbats are generally smaller than megabats, though not always (technical names: megachiroptera, microchiroptera). Megabats are often referred to as "Old World" bats because they are confined to the "Old World" tropics of Africa, Asia, and Indo-Australia. Microbats are the ones you are most likely to see in your backyard. Now, what is so interesting about all this? One did not evolve from the other. In fact, some scientists don't even believe they both evolved directly from the same ancestor!...These scientists feel that megabats evolved from lemur-like creatures (based on physical characteristics) and microbats evolved from shrew-like creatures. What is ridiculous about this? Well, it has occurred in lizards in the caribbean, but on a much smaller scale (size of legs, etc) due to similar selective pressures. While convergent evolution can indeed occur, it is always on a fairly small scale. The extraordinary degree of evolution (that is, extreme evolutionary changes) that would be required for producing a bat in the first place is hard to believe, let alone creating two types of bat that are very similar to each other and yet totally unrelated. The idea that this bizarre set of changes can occur separately with such similar results to such an extreme degree is hard for any realist to swallow.

Further hindering the bat evolution issue, is the fact that there are very few bat fossils found anywhere in the world.

Finally, let's look at our own species now (we aren't going to get too in depth with this because entire articles can be written on the subject). Similar to therapod-avian evolutionary models, every hominid find revolutionizes the field and the human family tree gets shuffled and reassigned. Just look at Kenyanthropus platyops, the new hominid find in Turkana, Kenya. Evolutionists may be kicking Lucy, our wonderful Australopithecine ancestor (afarensis), right out of the genealogy in favor of our platyops fellow (which coincidentally, at this time, consists of a single, warped, skull). Ironically, it was Lucy who shot to stardom and helped to make human evolution a common concept, to be taught in schools. Just look at this genealogy, published in the March 22nd edition of Nature, of our hominid ancestry. Is this the solid science evolutionists purport it to be?

There's a funny thing that happens whenever you try to classify something: there are always situations that defy your classification. The same thing happens when you try to break down species. Recall the manner in which speciation occurs; through reproductive isolation (or possibly also bacterial infection). Now, if you really want to convince yourself that everything is old and that historical evolution is, or is for the most part, true, then you may think that species crossbreeding in some situations is only a fluke. That's what most evolutionists do; they say, "hmm, weird" and then ignore it. There is another conclusion you can draw from this, however, and that is that the reproductive isolation for the two species has been incomplete, or (more importantly in my opinion) inadequate. What do I mean by inadequate? I mean they haven't been isolated long enough.

This concept is especially important if you are a creationist, because this is one of the most important things you could expect to see. Creationists feel that the earth is very young, and was swept by the Noahcian flood between 4000 and 6000 years ago. The Bible records that animals were brought onto the ark in "kinds," and while we do not actually know the species brought on board, or how a "kind" was defined in this instance, we know that a great deal of post-flood specieation would have occurred slightly after. That gives each species (exempting the original ones on board the ark) an age of less than 6000 years. That means that the reproductive isolation really hasn't gone on that long.

Lions and tigers, it turns out, can interbreed. In the wild, most lions live in Africa and most tigers live in Asia. Where they do come together, they are enemies. In the wild they are completely isolated from each other reproductively, however when raised in captivity together, they can interbreed on their own (without human intervention) to create hybrid offspring known as ligers or tigons.

Examples of this abound, where physiologically and genetically similar animals interbreed despite the fact that evolution states they should not have that ability (remember that, in order for a species to split from another, it has to be reproductively incompatible with it). A cama is a cross between a llama and a camel, a bottlenose dolphin and a psuedorca bred to create a wholfin, a zonkey is a cross between donkey and zebra, a zorse is a cross between zebra and horse, and a mule is a cross between a donkey and a horse (although mules, zorses, and zonkeys are all sterile, that does not diminish the fact that the parent animals can interbreed to produce live young).

So why can these animals interbreed? Is it a freakish evolutionary fluke or the result of an event popular science fails to recognize? You can be the judge of that.

Evolution is an interesting thing. It oscillates back and forth; first to the right and then to the left, and then to the right again. Evolution is only rarely a unidirectional force. What you saw among the lizards of the caribbean was pretty unidirectional for that particular event and the molestus mosquito event was unidirectional. These unidirectional evolutionary events occurred because there was some sort of dramatic, permanent change in the environment. Such changes can consist of: the introduction of a new predator, the subtraction of a predator, the introduction of a new prey, the reduction or subtraction of a prey, or a permanent change in the physical environment around the watched species. The interesting thing about evolution, however, is that it is multi-directional, usually swinging back and forth from one extreme to another, like a pendulum. Perhaps this is a good time to finish our story about the Galapagos Finches.

In December, 1982, (still only a few years after the end of the drought), El Nino occurred. It was the wettest rain season ever observed in the Galapagos. If you'll recall, the finches still showed the extreme results of the drought in their physical appearance, but now there was a massive population boom-so much so that the population of finches that season quadrupled (that's an average of 6 young per couple) to two thousand! The desert turned into a jungle. The cactus was overwhelmed and washed away as the tribulus was smothered out by vines. The mass of seeds was 12 times greater now than the year before with 5 times as many caterpillars, roughly 4 times larger than before. On Daphne Major, the birds were living the good life. They ate as much as they want and had it easy. The euphoria was short lived, however, since only 57 millimeters of rain fell in the following two years. Once the seed supply had finally crashed, the birds started dropping left and right just like what occurred in the earlier drought. Lisle, the man collecting the data, was sure evolution was working, but didn't know how it was affecting his population. How do you think evolution affected the finch population? (no cheating now)

A: The population evolved just as it did before. Big birds with large beaks survived while the little ones died. The pre-existing results of evolution were further exaggerated.

B: There was no change in the population. All of the birds that survived the last drought, and their off-spring, were the best and equally equipped.

C: The smaller birds with smaller beaks survived the best, reversing the effects of the earlier drought.

If you picked C, you are correct. If you recall why birds with big beaks survived the last drought, it's because all that was left were the large, tough, caltrop fruit. But during the flood, the tribulus plant that produced it was choked out so that there was almost no caltrop fruit left. When the drought hit, even though there were hardly any seeds left, most of those seeds were still small and not caltrop. That means that the bigger birds with big beaks had to find more food than the smaller birds, but this was almost impossible due to the drought. The large birds starved and the small birds with small beaks survived to reproduce the next wet season. The population completely reversed itself from the previous evolution event and you couldn't have known that the beak growth had ever occurred without having actually witnessed it. Now the beaks were small and so were the birds. The pendulum had swung the other direction.

And the beautiful thing about evolution is that this is what it does; swing back and forth, and achieves a net gain of zero in either direction. Now, there are instances where a species will progress with a net gain (evolutionary change in measured in units called darwins), but these demand those special circumstances. Even when these odd events do occur, they can be short lived as well. Why weren't there any lizards on those caribbean islands to start with? They had been blown off by hurricanes, and no-one's sure how long those new lizards will be there. Evolutionists often tell us one of two things: that evolution is a constant force, or that it progresses through something called Punctuated Equilibria. First of all, evolution as a constant force isn't totally wrong. There is always natural selection in play, forcing certain characteristics to be reinforced in a species or group of animals, but this does not really create much change. In fact, all it does is reinforce a certain set of characteristics in the population over time and, in fact, drop the genetic diversity of the population, making it more uniform and less likely to experience major changes.

You see, there is this little thing called genetic drift, and it is based upon the idea that not all the genes in an animal will be passed on to it's offspring. You take about half from one parent and half from the other to get the offspring, but not all of the genetic material from one animal will be passed on to it's young. Invariably, some genetic material will be lost when the parent generation dies, and as generations come and go, the gene pool doesn't get any new input (unless there's a new population that joins them or some sort of unlikely, bizarre mutation). That means that, as time progresses, the group becomes uniform. Let's take an extreme example by looking at human race mixing. You take a group of white and black people (caucasian, african) and isolate them somewhere so that they must interbreed. With each generation, there are more mixed race people than those who are purely black and purely white. Eventually, the group will become a uniform population of one mixed race. This example can be applied to everything in a population: size, color, toe length, voice pitch, etc... It effects every physical and genetic aspect of the population.

But can you see where this becomes a problem for evolution? Look at the finches of Daphne Major during the first drought- the finches beaks didn't shrink. The finches with small beaks died and the ones with big beaks lived. That's why the population's beak size changed: it was already diverse. There was enough diversity in beak size in the island that some birds survived the drought and others didn't. Think, however, about what might have occurred if the finch population had grown uniform over the years. The birds probably would have all died (assuming beaks were all too small for cracking seeds). Do you think this doesn't happen? Why do you think we have extinctions? Humans are much to blame, but we certainly aren't the only factor. Many of the climate changes that are occurring right now are forcing extinction of some animals as we speak.

And so where was I going with this? Genetic drift is the main force in that slow, constant evolution of species we were talking about above. Genetic drift, however, severely hurts the species chances of surviving a catastrophic event (a rapid: climate change, predatory change, prey change) meaning that slow, constant evolution will more often end with extinction than success. It's good for looking at species in the past and what's going on right now in some populations, but isn't worth crap for looking at how our current environment of species came to be. The concept of slow constant evolution, anyway, is flawed since it requires a long-term lack of extraordinary events (that means no major short term climate, predatory, or food changes over the course thousands or hundreds of thousands of years). We observe slow, constant evolution in only a very small minority of animals, if truly in any at all. You can't tell these populations are changing because the changes are so small.

And yet the idea of punctuated equilibria over long periods of time is vitally flawed also. Punctuated equilibria is the concept of a species not changing much for a long time and then changing very rapidly in a short time. This runs into some of the same problems as the slow evolution, however. If the species remains unchanged for thousands of years, it will likely not be able to change rapidly at all (recall what would happen if the finches were all exactly the same). Punctuated equilibrium is fueled by a sudden change in the environment of the species. The population must rapidly adapt to it or face extinction, and so it adapts in the course of a few short generations. This doesn't work, however, if the population hasn't had any major stresses on it during the time leading up to the "major event," and so instead of getting rapid evolution, we get extinction. This idea of punctuated equilibria is based on two things: observations of current rapid evolution, and the disturbing lack of "transitional" fossils that has haunted the profession of paleontology to this day. While PE explains the lack of "transitionals," it doesn't work with current observations since those are almost always multi-directional, and unidirectional events are rare and limited (rare in that they only occur under unusual circumstances and are usually short-lived; limited in that the surviving population exhibits the refining of features and never the growth of new ones).

The best picture of historical evolution that I can see is this: the pendulum keeps swinging back and forth, but someone's pushing the grandfather clock across the street. This isn't a wholly flawed concept, but it does have a few problems. First of all, it is better than the others since it incorporates constant change, which makes sense theoretically and in the light of current observations. The pendulum swings back and forth as conditions slowly change, allowing the animal to evolve. There are a few problems with this though, such as the problem of "transitional" fossils and the significant lack thereof. Also, while this idea explains changes in climate and food supply, it does not explain major predatory changes (namely, the addition of new predators). Current observations show that the majority of predatory introductions result in a blitzkrieg scenario. The blitzkrieg scenario occurs when a predatory introduction to an environment results in the devastation and extinction of prey populations. A great example of this today has been the introduction of predatory snakes in the pacific islands and their effects on the bird populations. Some of the native birds have gone extinct and many are seriously facing extinction. In a large number of cases, human intervention is the only thing that has kept these birds alive. A historical perspective can be gained by looking at the effects of human migration onto the American continents. A large number of species extinctions coincided with this event, such as the disappearance of the mammoth.

Some species, on the other hand, survive. Deer have survived the human onslaught, but that is simply due to their sheer number and rate of reproduction. They're still easy to shoot and still jump in front of cars. If every time a predator was introduced to a region, all the prey died, we wouldn't have any life at all. We see that some prey do adapt by looking at wolf reintroduction to regions of the northern US and their effects on moose populations. Moose in regions where there had always been wolves had a 250% greater response to a wolf call than those who hadn't experienced a wolf during their lifetime. Mother moose in areas where wolves were reintroduced, who had lost a calf, showed a response 500% greater than other moose around it. This shows that a response to predators can be learned, but mind that it is relatively rare. So what does this mean? Does it mean that MY-evolution is true or a flood model is true? Yes. The data superficially supports both. It's survival of the fittest; according to M.Y.-evolution, over time the animals that could adapt to handle predators survived. According to most post-flood models, the animals that were able to most quickly adapt to the new environment survived. There is one interesting thing I should note, however: all models of MY-evolution work against this. First look at the slow, steady evolution. It demands slow steady change, but a blitzkrieg is anything but slow and steady and would rapidly induce extinction. In PE (punctuated equilibrium), the population remains unchanged for a very long time and then suddenly adapts. This is a very accurate model for bacteria and even insects where individual populations can easily exceed the millions. PE relies on the presence of some sort of beneficial mutation (we will not delve into the likelihood of that) shortly before the selective event, that causes the offspring of that mutated individual to survive much better than the rest of the population. This is unpredictable, though observable in bacteria, microbes, and even insects. The terrible odds of there being a specific mutation luckily occurring at the same time as this intense selective pressure is just too much for it to be applicable to most mammalian, avian, reptilian, amphibian, and icthyan species. Finally, consider the analogy of the pendulum and the grandfather clock being moved across the street. It is good for your average situation, but when you introduce a new efficient predator, you're suddenly sending a caravan of very large trucks toward your clock. No matter how far your pendulum swings or at what position it's at, it's about to be smashed by a blitzkrieg.

So, is evolution true? Good luck answering that question, as you can see the subject is far too complex to just answer like that. Yes and no. Yes, in that biological evolution, in the factual sense of the word, does occur around us constantly as seen in the examples starting off this article. In fact, if you ever hear someone tell you that species do not evolve at all, period, then you can reasonably assume that they have not been doing their homework or reading reliable scientific texts. Biologic evolution, the change within a species and the arisal of new ones, is an observable, proven, and mildly predictable fact of life. Evolution in the historical sense (ex-nihilo evolution, de unum evolution, million year evolution, etc) is vitally flawed, however, in the concepts it introduces. As you've just seen, no model of evolution can adequately explain how things over the long term got here (we will not discuss some of the insurmountable obstacles in the evolutionary path to some of our present species at this time, though it is highly recommended that you look into such things). If this world were a gentle place, with nature as forgiving and genetics as helpful as we'd like to think they are, then at least one of the models might work. We don't see this, however. Moreover, you can't simply assume that a person who believes this to be true hasn't studied the subject; there are many rather intelligent people who believe it and have spent their lives studying it. The problem is that the flaw lies subtly in the logic and inferences rather than glaringly obvious in the raw collected data. That's why so many "brilliant" men miss it. You can look at those proofs for evolution I gave at the top all day. You can study them for your entire life and say "I think Darwin is right about how animals change. Maybe life came to it's present form through this process." If you don't take about ten steps back to look at it, however, you can fall for some fatal mistakes in the theory.

THIS CREVO THREAD has over 2,400 posts on it. Is it possible to say the same things all over again (someone said it is like the movie, "Groundhog Day") ?

Before beginning, let's save bandwidth with a coded reference system:
"C1" = "God said it, I believe it."
"C2" = "...tornado...junkyard...jumbo jet..."
"C3" = "...evidence...intermediate species..."
"C4" = "Psalm 139"

and...

"E1" = "And I am not...I repeat...I am NOT medved!"
"E2" = "...billions of years..."
"E3" = "...original horizontality...climate change...fossil record..."
"E4" = any picture sequence like this:

I love Articles like this. I always point out two simple facts

1. Go out to the country on a clear night and look up. What do you see, lots of stars. If you know where to look and it's relatively dark enough, you can easily see The Andromeda galaxy. Andromeda is the closest large galaxy(like the Milky Way). The photons of light that register on your retina have been traveling for roughly 2.3 million years. And this is the closest large galaxy. The most distant galaxy/object spotted so far is roughly 15 Billion light years away(Granted, with constantly moving away, the exact distance will vary but even with an order of magnitude, that's 1.5 billion light years). So what does that mean? We are dealing with vast periods of time. Not the six thousand years the Wacko Creationists believe.

2. Go out the front door and stand on the closest peice of dirt/grass you can find. Not start digging to look for fossils. I'd bet that 99.999999% would find nothing after a very long time searching. What does this mean? Well, I'd bet that in that very spot, there has been some form of life living in/on/over it for at least one billion years. So in all that time, you can find no fossil evidence of past life(I'm not talking about candy wrappers or other garbage, pure simple fossils like in the museums). What does that tell you? Simple, fossils are very, very rare. Sure you can go some places and find them all over the place, but the total of what you find is from millions of years of growth on that land. Do you think you could find enough fossils to reconstruct a garden bed at one time, let alone millionsof square miles of constant growth for hundreds of millions of years? Little know fact for you people - Before 1990 there were only ever 6 incomplete T-Rex's found in the entire world. I wonder how many actually existed through out history?

All of this boils down to refute the simplist of Creationist theories. You can't get from animal A to animal Z by evolution. The only reason they are able to say this is because we havn't found the very rarest evidence(fossils). Ahh but what happens when there is an animal(M) found that is between A and Z? Well, in the creationist argument you get the following. You can't get from animal A to animal M, nor from M to Z. Wash, Rinse, Repeat

Believe me, I'm a devout Christian, but that doesn't mean I have to check my brain at the door when it comes to Where/When/How/Why it all began. Unless God is playing a trick on us by craeting the Universe six thousand years ago and making it appear that it is > 13 Billion years old, I'll believe in an old Universe with a constant, omnipotent, loving caretaker making sure things work the way they do.

So, is evolution true?

Is the theory of gravity "true"?

Science doesn't concern itself with apparently unresolvable theological questions, generally. Evolution is a pretty good story that seems to explain quite a lot, and we'll probably persist in telling it until a better story comes along. What you've called cladistic theory has not been seriously on the table, aside from the occasional freak accident, even for life's origins, for a couple of years now, ever since Woese's rearrangement of the basic roots of the Tree of Life, about 3 years ago, from Ribosomal mutational distance calculations over the domain of one-celled critters. You might recall that about 15 years ago, the micro-biologists were confidently predicting the demise of the osolote cats because their numbers had shrunk down below critical reproduction mass, with the consequent catastrophic loss of genetic variety. By the way, this argument fares very poorly if you restrict your attention to asexual reproducers, who can (at least, so we at first thought) only evolve by mutation--no sex means no dominent and recessive genes to mix&match with--and probably isn't nearly as much fun.

Those who like to mull such things over, now generally subscribe to hot, weakly cohesive pre-cellular RNA communities, organized around energy-capturing enzymatic cycles (such as the citric cycle you digest your food with) gradually getting fixed into cellularity as the available energy became less available as the earth's mean temperature decreased. I can give you pointers, I think, if you are interested.

A tiny bit of the famous "list-o-links" (so the creationists don't get to start each new thread from ground zero).

01: Site that debunks virtually all of creationism's fallacies. Excellent resource.
02: Creation "Science" Debunked.
03: Creationi sm and Pseudo Science. Familiar cartoon then lots of links.
04: The SKEPTIC annotated bibliography. Amazingly great meta-site!
05: The Evidence for Human Evolution. For the "no evidence" crowd.
06: Massive mega-site with thousands of links on evolution, creationism, young earth, etc..
07: Another amazing site full of links debunking creationism.
08: Creationism and Pseudo Science. Great cartoon!
09: Glenn R. Morton's site about creationism's fallacies. Another jennyp contribution.
11: Is Evolution Science?. Successful PREDICTIONS of evolution (Moonman62).
12: Five Major Misconceptions about Evolution. On point and well-written.
13: Frequently Asked But Never Answered Questions. A creationist nightmare!
14: DARWIN, FULL TEXT OF HIS WRITINGS. The original ee-voe-lou-shunist.

The foregoing was just a tiny sample. So that everyone will have access to the accumulated "Creationism vs. Evolution" threads which have previously appeared on FreeRepublic, plus links to hundreds of sites with a vast amount of information on this topic, here's Junior's massive work, available for all to review:
The Ultimate Creation vs. Evolution Resource [ver 16].

I've seen that link about abiogenisis a couple of times, though it's proponents will mount fierce arguments to the contrary, it just recapitulates the "windstorm can't build a 707" argument. If you want to make an argument that the odds don't favor an occurance, than I want to see the stochastic calculation: what is the state-space, exactly, and what were to criteria for successful selection from the state-space?

If you don't show me that math, this argument is so much wind. It amounts to saying that, because I can't conceive how something occured, therefore the odds against it are astronomical. This would be transparent nonsense if it were not so often accompanied by polysyllabic scientisms and apparent examples concocted from the imagination, as with Behe et. al.

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