Biological evolution
From CreationWiki, the encyclopedia of creation science
Biological evolution, not to be confused with the theory of evolution, is the observable process through which the characteristics of organisms change over successive generations, by means of mutation, genetic recombination, natural selection, and genetic drift.
Changes such as metamorphosis or embryonic development are not considered biological evolution. Biological evolution transcends the lifetime of a single individual. The changes in populations that are considered evolutionary are those that are inherited through genetic information from one generation to the next.
Biological evolution may be minimal 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 to the diversification of the created kinds to countless unique species.
Many also use the term biological evolution to refer to the common descent of living organisms from shared ancestors. However, since this extrapolation of the process is highly theoretical, it is better addressed as part of the general theory of evolution.
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Mechanisms
Biological evolution can be summarized as a change in allele frequency in a population over time, and involve the following as explanatory mechanisms:
Genetic Diversity
- Main Article: Genetic recombination
Genetic recombination encompasses a number of mechanisms by which DNA is reshuffled in each generation, so that children are genetically distinct from the parents. It includes both the reorganization of genes that occurs in sexual reproduction, as well as the creation of new alleles. It is the primary source of genetic diversity and variation in gene pools.
The observable facts of genetic recombination are not in dispute between creationists and evolutionists. In fact, the principles of heredity and recombination were first discovered by Gregor Mendel, a creationist, a monk, and a scientist. Subsequent research has determined that recombination takes place even below the level of the gene, so that new alleles can be formed by the reshuffling of genetic material.
Evolutionists and creationists disagree, however, on the nature of this reshuffling. Evolutionists view it as random, accidental mutations. Creationists, on the other hand, believe that organisms were designed with the ability to reshuffle genetic material to introduce genetic diversity to a gene pool.
In support of their view, creationists point to the observable fact that genetic recombination does not follow a random pattern. On the contrary, some sections of the genetic code vary and recombine a great deal, while other sections vary little if at all. Sections that vary a great deal include skin color, height, muscle mass, intelligence, etc. Sections that do not vary much, if at all, include those controlling metabolism, cellular structure, and similar fundamental, structural components. Creationists argue that if variation were random, then we would expect to see variation at an equal rate across the genome. They argue that the fact that recombination occurs in a non-random pattern indicates that there is some mechanism controlling the variation to allow it only in places that are advantageous to the genome, a possibility that supports the creationist hypothesis.
Speciation
- Main Article: Speciation
Creationists would also agree with evolutionary biologists that the processes of genetic recombination and natural selection can result in the formation of new species. In fact, creationists believe that extremely rapid evolution occurred after the Flood to create the species that we see today from the smaller number of species that were on the ark.
Creationists find themselves at odds with evolutionists in regards to naturalistic abiogenesis and common descent. These aspects of the theory of evolution are simply unsupported by the scientific method, and largely the result of atheistic philosophy. As such, the belief that evolution alone is responsible for all organisms on earth is better classified as evolutionism.
Natural Selection
- Main Article: Natural Selection
Traits are found to exist within a population in a variety of forms, and these differences will afford individuals a greater or lesser chance of success. If the trait is beneficial to the organism, then its genes will be passed to the next generation at a higher frequency, or vice versa if it is harmful. This is said to be the "natural selection" of a trait.
The fact that natural selection happens is not open for dispute. Organisms do adapt to their environment and the role of natural selection in this process is certain. However, evolutionists do not view genetic information nor the cellular mechanisms responsible for genetic diversity as being the result of intelligent design. The theory of evolution assumes that random mutations are responsible for this information or the variability from which nature selects.
Common Descent
- Main Article: Common Descent
When referring to biological evolution it is important to make a clear distinction between the process that induces change in a population and common descent as purported through the general theory of evolution. The process itself is an obvious, observable, empirical fact that organisms vary genetically and morphologically through successive generations. On the other hand, the theory of evolution is the historical speculation that life originated naturalistically without any creative act (abiogenesis), that all life on Earth is related (common descent), and that all the complexity, adaptability, and artistry of life on Earth is due solely to random change and natural selection. Creationists acknowledge the process of biological evolution, but they assert that the theory of evolution is a farce, contradicted by enormous amounts of scientific evidence.
Explanatory power of biological evolution
The theory of evolution holds that every characteristic of every organism arose through genetic variation and natural selection. In contrast, creationists believe that biological evolution can explain some characteristics, but that others bare the hallmarks of intelligent design.
The process of biological evolution can only exist within organisms already able to reproduce, and each appears only able to evolve within the bounds of their original framework. For example, biological evolution can lead to a change in the size of a bird's beak or a change in a population's skin tone, add fur, allowing the organism to adapt and find its niche. It cannot explain major irreducibly complex aspects of biology, like sexual reproduction or blood clotting. Nor can it account for evolutionary predictions such as molecules-to-man, fish to amphibian or ape to man massive change.
Creation scientists credit major structural characteristics to God's creation, and credit variation within that structure to the designed process know as biological evolution.
Origin of biological evolution
Creationists and evolutionists disagree on the origin of biological evolution: that is, how life came to have the ability to reproduce and vary over generations.
The theory of evolution holds that life's capacity for biological evolution came about by chance and natural selection: that chemicals moving randomnly in the universe reached a certain (as yet unknown) configuration that allowed them to reproduce, and that through the process of reproduction, those chemicals came to vary by chance after each copy, and the variations of those chemicals which encouraged reproduction spread more than those that did not.
Creationists, on the other hand, believe that life was created and intentionally given the capacity for biological evolution. Thus, the capacity to reproduce and vary is itself credited to God's creative act. God endowed life with the capacity for biological evolution so that life could thrive and spread over the earth: so that it could adapt to changing conditions. Creationists see genetic recombination as strong evidence for this: specifically, the fact that certain areas of the genome (such as those controlling body shape) vary a great deal, while others (such as those controlling the operation of cellular organelles like the mitochondria) vary little if at all, indicates that there is some mechanism guiding the process of variation itself, causing the genome to vary where variation is useful, and remain virtually unchanged where variation will most likely be harmful.
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