"In biology, evolution is the measurable change in the heritable traits (allele frequency) of a population over successive generations. Evolution is ultimately the source of the vast diversity of the biological world. Over time, it may result in the origin of new species (speciation). Contemporary species are related to each other through common descent, products of evolution and speciation over billions of years." translation organisms change over time due to adapting to their environment and selective breeding, though natural selection plays the largest role in evolution, in natural selection the animal that is best fit to live in and survive in its environment will be able to live on and reproduce. Also known as "survival of the fittest"
2006-06-17 19:26:35
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answer #1
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answered by ecceromani! 1
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A theory first proposed in the nineteenth century by Charles Darwin, according to which the Earth's species have changed and diversified through time under the influence of natural selection. Life on Earth is thought to have evolved in three stages. First came chemical evolution, in which organic molecules were formed. This was followed by the development of single cells capable of reproducing themselves. This stage led to the development of complex organisms capable of sexual reproduction. Evolution is generally accepted as fact by scientists today, although debates continue over the precise mechanisms involved in the process.
2006-06-18 02:34:43
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answer #2
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answered by Jane M 2
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Common usage of the word "evolution" is the idea that living things in our world have come into being through unguided naturalistic processes starting from a primeval mass of subatomic particles and radiation, over approximately 20 billion years.
A more precise understanding of the above statement divides the "atoms to people" transition into four realms:
Cosmology is the branch of astronomy which deals with the origin and formation of the general structure of the universe.
Abiogenesis refers to first life - the production of living organisms from inanimate matter.
Micro-evolution or speciation refers to populational and species change through time. There are many published examples of speciation, if by the development of a new "species" we mean the development of a new population of individuals which will not breed with the original population to produce fertile offspring. Micro-evolution is a scientific fact which no one, including creationists, dispute.
Macro-evolution or general evolution refers the progression to more complex forms of life. The mechanisms of macro-evolution, including whether or not micro-evolution over a long enough time leads to macro-evolution, can be regarded as a "research topic" (Berra 1990, 12).
The popular mechanisms for explaining micro-evolution are "mutation" and "natural selection".
Mutations are "mistakes" introduced into the genetic material used for reproduction, which can occur for example as a result of exposure to radiation. Naturally occurring mutations are very rare, and it is acknowledged that of those that do occur, almost all have a negative effect (in fact, some creationists argue there is not a single known case of a truly positive mutation, one having no negative side-effects). The occasional positive mutation, giving some benefit to the organism, provides the "new material" for natural selection to operate on.
Natural selection is based on the observation that there is variation among individuals in a population. Natural selection states that those individuals which posses some advantage in the environment (such as being a faster runner) are more likely to leave more offspring, thereby increasing the probability of passing the advantage on to future generations. Natural selection is what "retains" the occasional positive mutation and causes the population to "advance" is some way. Creationists note that this mechanism can only "select" among already existing traits - it cannot create something new.
A classic example of natural selection is the peppered moth changing its predominant color in response to environmental pollution from in industrial era of England. Here, the predominance of white moths was shifted to dark moths, allowing for camouflage against predatory birds, as the trees darkened. Before the population shift occurred both light and dark moths were present. The environment allowed one shade to flourish. However, what if the pollution covering the trees on which they rested was a bright purple, making both the light and dark moths highly visible. Would the moths become purple?
Experiments and knowledge to date demonstrate that adaptation has limits beyond which no more change is possible. Selective breeding of roses has never been able to produce a blue-colored rose.
2006-06-18 02:27:01
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answer #3
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answered by Harsh 2
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#1. Living things (organisms) have physical and behavioral characteristics (adaptations), which help them to survive and reproduce.
#2. Adaptations are passed down from one generation to the next through a hereditary mechanism (DNA, RNA, RNA precursors).
#3. The hereditary mechanisms are imperfect, producing occasional changes (mutations) to the encoding for adaptations.
#4. Mutations are either preserved or eliminated depending on how any changes effect an organisms ability to survive and reproduce.
That's the basics, the specifics of mutation, heredity, population genetics, and natural history are far more complicated. More so than can be explained comfortably in this format.
2006-06-18 11:00:41
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answer #4
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answered by corvis_9 5
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The theory, simply put, is that all living things evolve to fit their ever changing environment. If the going gets tough, the tough get going.
2006-06-18 02:24:18
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answer #5
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answered by oneblondepilgrim 6
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theory of evolution accdg. to charles darwin is that man came from apes and that every living organism today had a predecesor
2006-06-18 02:26:34
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answer #6
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answered by ang_kulit49 2
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the word evolution has been derived 4rm latin word evolvere which means to unroll. it is defined as "the gradual unfolding of organisms 4rm pre existing organisms through change since the beginning of life"
2006-06-18 04:31:56
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answer #7
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answered by nora 3
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I am afraid the only person who can answer this question is a man(or woman, for those feminist) who has evolved.
2006-06-18 02:26:52
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answer #8
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answered by itwasntme_x2 1
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absoltely bull shitorino
2006-06-18 07:23:55
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answer #9
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answered by je l 1
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im just guessing, but I think it's every generation it evolves more?
2006-06-18 02:23:28
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answer #10
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answered by laurennn 3
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