Microevolution and Macroevolution

By Do-While Jones

Microevolution is the process that is responsible for the many variations of some species of living things, such as dogs and finches. Macroevolution is the mythical process by which one kind of creature, such as a reptile, turns into another kind, such as a bird. It is argued by evolutionists that given enough time, the small changes caused by microevolution can add up to big enough changes to create entirely new species. Although this argument may seem reasonable on the surface, closer examination shows that it must be false.

When Darwin was on the Galapagos Islands, he correctly observed that some finches, which had been separated from other finches of the same species, had acquired distinctive characteristics (unusual beaks or feathers). He correctly concluded that these birds had evolved, in a particular sense of the word. They truly had undergone microevolution.

Most creationists agree that microevolution does occur. In fact, Biblical creationists ¹ insist that it does. Microevolution is their explanation for how all the human races came from Noah's family. They say the races of men are the result of microevolution. Let's see how microevolution works.

Selective Breeding

Imagine that a Boeing 747 full of people crashes safely on an uncharted tropical island. Most of these people have brown eyes, but a few have blue eyes. At the risk of over-simplifying the genetics, this is because brown-eye genes are dominant, and blue-eye genes are recessive. If a child inherits brown-eye genes from one parent, and blue-eye genes from the other parent, then the child will have brown eyes. If a child inherits brown-eye genes from both parents, the child will have brown eyes. The only way for a child to have blue eyes is to inherit blue-eye genes from both parents.

Suppose that the passengers in our illustration aren't rescued for several generations. Suppose further that a blue-eyed leader gains supremacy shortly after the crash and decrees that all children who aren't born with blue eyes will be killed immediately. After several generations, all the people on the island will have blue eyes. No more brown-eyed children will ever be born because the brown-eye gene has been eliminated from the population. This new race of people will probably have other distinguishing characteristics that result from this ruthless selection process because one gene often has several effects, and other genes might be lost in the selection process, too. A new race of people will have evolved through the process of microevolution.

Now let's consider this analogy. Suppose you have a Scrabble game. You can draw seven letter tiles from it and make a wide variety of English words. But suppose you and your spouse divorce, and the judge rules that all community property must be evenly divided. You get half of the tiles and half of the board. If you happen to get the one Q tile, you will tend to form words like quick, queen, quiet, and acquire whenever you play the game. Your spouse will never be able to form these words. When you die, your property is evenly divided among your four children. Each child gets ¼ of your tiles and ¼ of your half of the board. Each child will be even more limited in the selection of words that can be formed when the child plays the game. Each child will have a different set of possible words that can be formed because each child has a different set of letter tiles. As the number of available tiles decreases, a distinctive set of possible words evolves for each child's game. There comes a point, however, when you just can't take away any more tiles and still be able to make words.

In both examples, particular results become inevitable because of a loss of possible variations. Microevolution can (and does) result in a group of individuals with distinctive characteristics. Dog breeders, pigeon breeders, and horse breeders have all discovered that there is a limit to how many distinctive characteristics they can produce through selective breeding. Once they get rid of all the dominant genes that were preventing the desired recessive genes from surfacing, there is nothing more they can do.

One can breed a race of blue-eyed people by removing all the brown-eye genes from the gene pool. One can't breed a race of blue-haired people, though, because there isn't any blue-hair gene already existing in the population. Acquiring a totally new feature, like blue hair, requires new genes. Since microevolution is the process of losing genes, it cannot produce any new features.

Mutations

Mutations are caused by random changes in genes. Is it possible that a mutation could produce new genes that would create a new species? Let's consider that possibility.

It is possible that somewhere there could be a colony of flying ants. It might happen that the queen of this colony might suffer some genetic accident that damages the gene that causes wings to form. Her offspring would not have any wings, and naturally would not be able to fly.

The inability to fly is certainly not an advantage, so one would not expect that natural selection would cause them to beat the flying ants in the battle for survival. This mutation would be a disadvantage. But inability to fly might not be such a large disadvantage that the non-flying ants could not survive. These non-flying ants might not mate with the flying ants, and so they would be considered to be a new species. This is not evolution in the Darwinian sense because a "higher" (or superior) species has not been created. Quite the opposite. This hypothetical new species of ant is a step backwards, not forwards. It has lost the ability to fly because it has lost a required gene. It now also has some left-over "junk DNA" designed to control the wings it no longer has. This junk DNA no longer serves any purpose.

It could be said that the ant "devolved" because the new species is inferior. Devolution is consistent with the second law of thermodynamics. Given enough time, and left to themselves, things fall apart. Things don't naturally fall together. So it is possible that flying ants could devolve into ordinary ants because one of the genes needed for flying could be lost or damaged.

For flight-challenged ants to evolve into flying ants, at least one new gene would have to be added. There is no evidence that this happens now, or has ever happened in the past. "Gene-jockey" scientists have transplanted genes to create novel characteristics in laboratory animals, but new beneficial genes don't just appear by magic in a natural process. Genes naturally get worse, not better.

If you write a document, then let someone change some of the letters at random, the document will make less sense, not more sense. If you randomly change op codes in a computer program, the program will not improve. Random mutations do not make things better.

Loss is Not Gain

Scientific studies have shown us that species can lose genetic information either through loss of genes from selective breeding, or from mutation. As a result, the new species has only a subset of previously existing characteristics. The loss of characteristics may make the new species so much inferior to the previous species that it may not be able to survive, and may become extinct. There is abundant evidence that extinction has happened to most of the species that have ever lived.

It is possible, however, that a new species will survive despite its handicap. The new species devolves from a higher life-form to a challenged life-form. Some of the species we see today may not be as capable as their ancestors were, but they are not extinct because they have learned some way to compensate. There are blind fish that live deep in the ocean. Their blindness isn't much of a handicap because there isn't much light down there anyway, so they survive.

It is easy to see how one who doesn't understand the process might think that the cumulative effects of small changes from eons of microevolution could result in macroevolution. But microevolution removes genes from the gene pool. Macroevolution requires adding new genes with special capability. You can't get more of anything by removing some of it.

In the 20th century we have learned many things about genetics, thermodynamics, probability, and information theory that weren't known when Darwin developed his theory. These new discoveries give abundant evidence that lower forms of life can't evolve into higher forms. In the 19th century, Darwin could be excused for thinking that what he saw on the Galapagos Islands could explain how life appeared on Earth. Today there is no excuse.

Footnote:

¹A Biblical creationist is a special kind of creationist. A creationist is anyone who believes that life as we know it is the result of an unspecified intelligently guided process. A Biblical creationist is one who believes that the process that created life is the one described in the book of Genesis. (Ev)

 

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