evolution


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Related to evolution: theory of evolution, Evolution of Man

evolution

 [ev″o-lu´shun]
the process of development in which an organ or organism becomes more and more complex by the differentiation of its parts; a continuous and progressive change according to certain laws and by means of resident forces.
convergent evolution the development, in animals that are only distantly related, of similar structures or functions in adaptation to similar environments.

ev·o·lu·tion

(ev'ō-lū'shŭn),
1. A continuing process of change from one state, condition, or form to another.
2. A progressive distancing between the genotype and the phenotype in a line of descent.
3. The liberation of a gas or heat in the course of a chemical or enzymatic reaction.
[L. e-volvo, pp. -volutus, to roll out]

evolution

/evo·lu·tion/ (ev″ah-loo´shun) a developmental process in which an organ or organism becomes more and more complex by differentiation of its parts; a continuous and progressive change according to certain laws and by means of resident forces.
convergent evolution  the appearance of similar forms and/or functions in two or more lines not sufficiently related phylogenetically to account for the similarity.
organic evolution  the origin and development of species; the theory that existing organisms are the result of descent with modification from those of past times.

evolution

(ĕv′ə-lo͞o′shən, ē′və-)
n.
1. A continuing process of change from one state, condition, or form to another.
2. Change in the genetic composition of a population during successive generations, often resulting in the development of new species. The mechanisms of evolution include natural selection acting on the genetic variation among individuals, mutation, migration, and genetic drift.

evolution

[ev′əlo̅o̅′shən]
Etymology: L, evolvere, to roll forth
1 a gradual, orderly, and continuous process of change and development from one condition or state to another. It encompasses all aspects of life, including physical, psychological, sociological, cultural, and intellectual development, and involves a progressive advancement from a simple to a more complex form or state through the processes of modification, differentiation, and growth.
2 a change in the genetic composition of a population of organisms over time.
3 the appearance over long periods of time of new taxonomic groups of organisms from preexisting groups. Kinds of evolution are convergent evolution, determinant evolution, emergent evolution, organic evolution, orthogenic evolution, and saltatory evolution. evolutionist, n.

ev·o·lu·tion

(ev'ŏ-lū'shŭn)
1. A continuing process of change from one state, condition, or form to another.
2. A progressive distancing between the genotype and the phenotype in a line of descent.
[L. e-volvo, pp. -volutus, to roll out]

evolution

The theory that all living organisms have developed in complexity, from a simple life form. Evolution occurs by the natural selection of those who, by the fortune of spontaneous random changes (mutations), happen to be best suited to their contemporary environment, to survive and reproduce. It does not occur by the passing on to offspring of characteristics acquired during the lifetime of an individual. Characteristics are passed on by the transmission of DNA from parents to offspring and, unless mutation has occurred, this DNA is an identical copy of the DNA of preceding generations.

evolution

an explanation of the way in which present-day organisms have been produced, involving changes taking place in the genetic make-up of populations that have been passed on to successive generations. According to DARWINISM, evolutionary MUTATIONS have given rise to changes that have, through NATURAL SELECTION, either survived in better adapted organisms (see ADAPTATION, GENETIC), or died out. Evolution is now generally accepted as the means which gives rise to new species (as opposed to SPECIAL CREATION) but there is still debate about exactly how it has taken place and how rapidly changes can take place. See LAMARCKISM.

evolution

the process of development in which an organ or organism becomes more and more complex by the differentiation of its parts; a continuous and progressive change according to certain laws and by means of resident forces.

convergent evolution
the development, in animals that are only distantly related, of similar structures or functions in adaptation to similar environment.
divergent evolution
the development of different characteristics in animals that were closely related in response to being placed in different environments.

Patient discussion about evolution

Q. How the bacterias are produced?

A. The Bacteria are a large group of unicellular microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals. (The name comes from the Greek bakterion, meaning small staff.) Bacteria are ubiquitous in every habitat on Earth, growing in soil, acidic hot springs, radioactive waste,[2] water, and deep in the Earth's crust, as well as in organic matter and the live bodies of plants and animals. There are typically 40 million bacterial cells in a gram of soil and a million bacterial cells in a millilitre of fresh water; in all, there are approximately five nonillion (5×1030) bacteria on Earth,[3] forming much of the world's biomass.[4] Bacteria are vital in recycling nutrients, with many important steps in nutrient cycles depending on these organisms, such as the fixation of nitrogen from the atmosphere and putrefaction. http://en.wikipedia.org/wiki/Bacteria Hope this helps.

More discussions about evolution
References in periodicals archive ?
In a survey of Oklahoma biology teachers, for example, 12% favored omitting evolution from biology classes and teaching creationism in its place (Weld & McNew, 1999).
We know what they are taught in school -- evolution -- (and) we want them to question this.
He had assumed that it was "a done deal" that religion could not be taught in the science curriculum and that public schools could not take actions to undermine the teaching of evolution for religious reasons.
With "critical analysis," creationists evidently hope to sow enough doubts in people's minds to convince them that the theory of evolution should be treated with more skepticism than it currently is.
Evolution, on the contrary, is a totally different matter, because it is an ideology, it is not ordinary science; so if you are a professor of biology in a university, especially in the Anglo-Saxon world, less so in Italy, France, and Germany, and if you oppose the theory of evolution on purely scientific grounds, you are rejected and even ejected from your position, your colleagues think you are insane, you do not get promotions, and so on.
Of special note are 2 chapters that are often missing in traditional medical microbiology books: 1 describes how long-term experimental evolutionary studies in the laboratory can contribute to our understanding of microbial pathogen evolution in the environment and clinics, and the other describes how gene inactivation and gene loss can be creative forces during the evolution of many microorganisms, especially obligate intracellular pathogens.
Father Rafael Pascual's interview on "Creation and evolution can be compatible" makes the false assumption that evolution is a viable theory, though he explains clearly that it does not necessarily detract from our Catholicity.
For information on evolution, including teacher resources, visit this Web site: http://evolution.
State boards in Kansas and Ohio, among others, have adopted science standards that call for critical analysis of evolution.
Kansas, of course, has been the firestorm capital of the struggle surrounding evolution teaching in this generation--even though its new science standards approved in November 2005 do not even advocate intelligent design per se.
Schonborn further argued that a 1996 letter by John Paul II, in which the late pope referred to evolution as "more than a hypothesis," did not mean that John Paul gave full support to the theory of evolution, as some have claimed.
CRITICAL THINKING: Refer students to the comment of biology teacher Jen Miller, who says she sees no contradiction between the teaching of evolution and a belief in God.