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 EVOLUTION

In biology, evolution is the process by which novel traits arise in populations and are passed on from generation to generation. Its action over large stretches of time explains the origin of new species and ultimately the vast diversity of the biological world. Contemporary species are related to each other through common descent, products of evolution and speciation over billions of years. The phylogenetic tree on the right represents these relationships for the three major domains of life.

The understanding of evolution is based on the theory of natural selection, which was first set out in a joint 1858 paper by Charles Darwin and Alfred Russel Wallace, and achieved a wider readership in Darwin's 1859 book, On The Origin of Species. Natural selection is the idea that individual organisms which possess variations giving them advantageous heritable traits are more likely to survive and reproduce and, in doing so, increase the frequency of such traits in subsequent generations.

Here's a general term encyclopedia.

In the 1930s scientists combined Darwinian natural selection with the theory of Mendelian heredity to create the modern evolutionary synthesis (often simply called the modern synthesis). The modern synthesis understands evolution to be a change in the frequency of alleles within a population from one generation to the next. The mechanisms that produce these changes are the basic mechanisms of population genetics: natural selection and genetic drift acting on genetic variation created by mutation, sex, and gene flow. This theory has become the central organizing principle of modern biology. It helps biologists understand topics as diverse as the origin of antibiotic resistance in bacteria, eusociality in insects, and the staggering biodiversity of the living world.

Because of its potential implications for the origins of humankind, the evolutionary theory has been at the center of many social and religious controversies since it was first introduced.

The idea of biological evolution has existed since ancient times, notably among Greek philosophers such as Epicurus and Anaximander, however, the modern theory was not established until the 18th and 19th centuries, by scientists such as Jean-Baptiste Lamarck and Charles Darwin. Transmutation of species was accepted by many scientists before 1859, but the publication of Charles Darwin's On The Origin of Species by Means of Natural Selection provided the first cogent mechanism by which evolutionary change could occur: his theory of natural selection. Darwin was motivated to publish his work on evolution after receiving a letter from Alfred Russel Wallace, in which Wallace revealed his own discovery of natural selection. Accordingly, Wallace is sometimes given shared credit for originating the theory that evolution could be explained through natural selection.

Darwin's theory, although it succeeded in profoundly shaking scientific opinion about the development of life, could not explain the source of variation in traits within a species, and Darwin's proposal of a hereditary mechanism (pangenesis) was not compelling to biologists. Although the occurrence of evolution of some sort became a widely-accepted scientific belief, Darwin's specific ideas about evolution — that it occurred gradually by natural and sexual selection — were actively attacked and rejected. From the end of the 19th century through the early-20th century, forms of neo-Lamarckism, "progressive" evolution (orthogenesis), and an evolution which worked by "jumps" (saltationism, as opposed to gradualism) became popular, although a form of neo-Darwinism (led by August Weismann) also enjoyed some minor success. The biometric school of evolutionary theory resulting from the work of Darwin's cousin, Francis Galton, emerged as well, using statistical approaches to biology which emphasized gradualism and some aspects of natural selection.
 

INTELLIGENT DESIGN

Intelligent design (ID) is the concept that "certain features of the universe and of living things are best explained by an intelligent cause, not an undirected process such as natural selection." Its leading proponents, all of whom are affiliated with the Discovery Institute, say that intelligent design is a scientific theory that stands on equal footing with, or is superior to, current scientific theories regarding the origin of life.

An overwhelming majority of the scientific community views intelligent design not as a valid scientific theory but as pseudoscience or junk science. The U.S. National Academy of Sciences has stated that intelligent design "and other claims of supernatural intervention in the origin of life" are not science because they cannot be tested by experiment, do not generate any predictions and propose no new hypotheses of their own.

A United States federal court recently ruled that a public school district requirement for science classes to teach that intelligent design is an alternative to evolution was a violation of the Establishment Clause of the First Amendment to the United States Constitution. In Kitzmiller v. Dover Area School District (2005), United States District Judge John E. Jones III also ruled that intelligent design is not science and is essentially religious in nature.

Intelligent design is presented as an alternative to natural explanations for evolution. The stated[8] purpose is to investigate whether or not existing empirical evidence implies that life on Earth must have been designed by an intelligent agent or agents. William Dembski, one of intelligent design's leading proponents, has stated that the fundamental claim of intelligent design is that "there are natural systems that cannot be adequately explained in terms of undirected natural forces and that exhibit features which in any other circumstance we would attribute to intelligence."

Proponents of intelligent design look for evidence of what they term "signs of intelligence" — physical properties of an object that they assert necessitate design. The most commonly cited signs include irreducible complexity, information mechanisms, and specified complexity. Design proponents argue that living systems show one or more of these, from which they infer that some aspects of life have been designed. This stands in opposition to mainstream biological science, which relies on experiment and collection of uncontested data to explain the natural world exclusively through observed impersonal physical processes such as mutations and natural selection. Intelligent design proponents say that while evidence pointing to the nature of an "intelligent cause or agent" may not be directly observable, its effects on nature can be detected. Dembski, in Signs of Intelligence, states: "Proponents of intelligent design regard it as a scientific research program that investigates the effects of intelligent causes. Note that intelligent design studies the effects of intelligent causes and not intelligent causes per se." In his view, one cannot test for the identity of influences exterior to a closed system from within, so questions concerning the identity of a designer fall outside the realm of the concept.