This blog is intended for posting of news and information about science as related to the fact of biological evolution. ▼ Site Map ▼
Biological evolution is a fact that is demonstrated by an abundance of evidence too voluminous to list. Theories concerning mechanisms of biological evolution, which have moved beyond the Darwinism that creationists attack in strawman arguments, are empirically supported explanations for the operation of biological evolution.
"God did it by performing miracles" is no explanation at all, though it seems adequate for those with an inculcated, emotional insistence that they are God's special creations. Such people, in failing to employ critical thinking, cannot reasonably claim to be the product of 'intelligent design' because they demonstrate an emotion-distorted failure of understanding.
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Darwinism
Charles Darwin accurately predicted that his theories would evoke skepticism from scientists and ridicule from the religious. Happily, scientists came to accept his ideas, and his breakthrough insights have proved highly influential. Unhappily, those biblical literalists who insist that "Genesis" is an accurate description of life's origins, continue to unjustly vilify Darwin's theories.
Summary of Darwin's observations and his Theory of Evolution by Natural Selection:
1. Most animals have such high fertility rates that their population size would increase exponentially if all individuals were to reproduce.
2. Yet, except for seasonal fluctuations, populations remain relatively stable in size.
3. Because environmental resources are limited, individuals compete for resources, limiting survival and reproduction.
4. Individual characteristics vary within populations and those members of a population that are better adapted for survival in the face of competition are more likely to pass their characteristics on to the next generation.
5. Thus, species gradually accumulate inherited adaptations that best suit them for their environment, passing these on to progeny. Speciation involves gradually accumulated differentiation of characteristics.
Darwin was not aware of the existence of DNA, nor of the mechanisms that alter genotype. Darwin focussed on the inheritance of adaptive individual characteristics that had ensured reproductive success, and the resultant slow accumulation of adaptive phenotypic change. Darwin did not say that all species are gradually evolving (cf. quote.)
Subsequent evolutionary theorists first disputed Darwin's concept of gradual evolution. Gould and Eldredge introduced the concept "phyletic gradualism " which they discredited through the concept of punctuated equilibria. The Theory of Punctuated Equilibria was proposed in order to explain patchiness in the fossil record and the the localized adaptive radiation of species observed following extinction events. This stage of thinking about evolutionary mechanisms has been termed "Neo Darwinism".
Modern advances in molecular genetics, coupled with studies of population genetics have led to the "Modern Synthesis" of understanding concerning mechanisms of evolution. Current understanding incorporates knowledge of genetic drift, gene flow, mutation, recombination, and natural selection mechanisms.
Creationists and defenders of "intelligent design" theory commonly attack a "strawman" depiction of Darwinism or Neo-Darwinism as representing current thinking in their attempt to discredit evolutionary science. It is important for any person wishing to defend evolution-as-fact and modern evolutionary theories to attain a thorough understanding of modern evolutionary theory as well as fallacious creationist arguments.
