Definitions (Evolution)

by George Jelliss , Crewe, Saturday, March 29, 2008, 16:47 (5872 days ago)

In the "Quotation from Darwin" thread dhw asks for definitions of various terms. These are my understanding of them, and some others: - Science = The application of logical reason to data obtained by observation and experiment (this is called the scientific method), with the aim of developing systematic understanding of the whole of human experience (this is called scientific knowledge). The degree of confidence to be attributed to this knowledge will vary according to the evidence. Absolute certainty is impossible. - Ockham's razor = The principle that one should not make unnecessary extra assumptions. I consider this to be an important principle of logical reasoning, and therefore of science, though others of more baroque sensibilities may say it is a matter of aesthetics. - Evolution = The step by step changes over time that take place in any system. This is it's most general sense. Thus it can apply to the history of the whole universe from the big bang through the evolution of heavy elements in the stars, to the evolution of self-replicating molecules (i.e. the origin of life), to the evolution of the simplest life forms into varied species. - Darwinism = Evolution of life on Earth, from a single original form, by natural selection acting on variation, as expounded by Charles Darwin in his 1859 book "Origin of Species". The word was possibly first used by Alfred Russel Wallace, the co-discoverer of the theory, who wrote a book with this title. - Natural selection = The process described by Darwin whereby new species originate from earlier species, due to variations in the genetic characteristics within a population leading to those who carry the changes being better adapted to their environment and thus passing on their genes to the next generation (while those less well adapted do less well). - Chance = The happening of some event in an unpredictable manner. Whether we call something chance may depend on our knowledge of the circumstances leading to its occurrence. Examples: Someone is injured in a road accident. The impact of a radioactive emanation on a molecule alters its structure to produce a mutation (change) that makes it's chemical properties different. A quantum fluctuation in the void results in the appearance of a new universe. - Random = The happening of a chance event which is one of a set of possible events all of which could occur with equal probability. - Determinism = The belief that everything has a cause, and that with sufficient knowledge all chance events would have an explanation. - Indeterminism = The belief that there are events that have no cause, and are purely random. This is one of the bases of quantum theory. - Belief = The confidence one is prepared to place in various propositions about the nature of human experience. - Faith = Willingness to believe in something for which there is inadequate evidence. This may be for emotional or aesthetic reasons, and no doubt from other causes. It may often result from a strong "Trust" in the integrity of one's teachers. Faith is sometimes used when Trust would be a better term. Faith may be strong or weak. - Theism = Various forms of belief in the existence of supernatural forces that create, design or guide the phenomena humans experience, and possibly have intentions towards human beings and their history and future. - Atheism = Non-belief in theism. This may be from various motives, rational or emotive. For example someone brought up in a religion who has had bad experiences with the practitioners of the religion may hate the whole idea without having thought it out intellectually. - Scientific Atheism = Non-belief in theism because of the lack of scientific evidence for the truth of the claims of theists. (This of course is my position.) Since theistic claims are varied, the strength or weakness of the evidence for or against is also varied. In the weakest cases the non-belief may be simply an application of Ockham's Razor. - Agnosticism = Sitting on the fence between theism and atheism.