Macro-evolution

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'''Macro-evolution''' and '''micro-evolution''' are terms sometimes used in a [[scientific]] context, but more often thrown around by [[creationist]]s to get around some of the instances in which [[evolution]] has been observed. "Macro-evolution" means evolution on a large scale, while "micro-evolution" means evolution on a small scale. A common creationist claim is that micro-evolution has been observed, but macro-evolution never has.
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'''Macro-evolution''' and '''micro-evolution''' are terms that are sometimes used in a [[scientific]] context, but are more often thrown around by [[creationist]]s to get around some of the instances in which [[evolution]] has actually been observed. The basic idea is:
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*''Macro-evolution'' is evolution on a large scale.
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*''Micro-evolution'' is evolution on a small scale.
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Unfortunately, there is no clear dividing line between the "large" and "small" scales being referred to.
  
In science, however, there is no clear dividing line between the two.  To the extent that "micro-evolution" is a recognized term at all, it generally means change within species, while macro-evolution means change between species. Unfortunately for creationists, speciation '''has''' been observed in laboratory conditions -- scientists have successfully induced the evolution of new species that cannot breed with the original strains.
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== A problem of definition ==
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A common creationist claim is that micro-evolution has been observed, but macro-evolution never has. In fact, if any type of evolution is actually observed, it is likely to be ''called'' micro-evolution simply because of that fact. Thus, in this sense, the terms have little use beyond anti-evolution apologetics.
  
While it is obviously the case that nothing can be ''directly'' observed when it occurs on a large enough scale (i.e., longer than a human lifetime), macro-evolution is well confirmed through various tests and models.
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In science, to the extent that the terms are used at all:
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* ''Micro-evolution'' generally means change ''within'' a species.
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* ''Macro-evolution'' generally means change ''between'' species.
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The word ''species'' typically refers to a group of individuals that can interbreed with each other. So, for example, the huge variety of dog breeds that have resulted from hundreds of years of human influence would be an example of ''micro''-evolution, since different breeds of dog can still interbreed (though it may be physically awkward in some cases). However, since dogs and foxes, for example, cannot interbreed, the split of the two species from a [[common ancestor]] was an example of ''macro''-evolution.
  
==Biblical "Kinds"==
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Does this mean that speciation (a split of one species into two) cannot be directly observed? Certainly not. Speciation '''has''' been observed under laboratory conditions: scientists have successfully induced the evolution of new species<!-- in particular...? --> that cannot breed with the original strains.
Because speciation is an observed phenomenon, creationists like to redefine terms by talking about "macro-evolution" not in terms of species but in terms of "kinds."  But a kind is not a scientific notion, and creationists are notoriously vague when it comes to defining what it means.
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* For instance, is a chihuahua the same kind as a Saint Bernard?
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== Biblical "kinds" ==
* How about a chihuahua and a dire wolf?
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Because speciation is an observed phenomenon, creationists like to redefine terms by talking about macro-evolution not in terms of species but in terms of "kinds."  But a ''kind'' is not a scientific notion, and creationists are notoriously vague when it comes to defining what it means:
* How about a wolf and a house cat? They're both mammals and both in the carnivora family.
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* Is a chihuahua the same "kind" as a Saint Bernard?
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* How about a chihuahua and a fox?
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* How about a wolf and a house cat? (They're both mammals, after all — and even in the same family, ''carnivora''.)
  
In science, there is no clear dividing line between "kinds" beyond species (and even species can be a fuzzy term). Creationists do not agree with one another about exactly what "kind" means, either, and have never proposed a rigorous definition.  They only agree on the [[ad hoc]] sense that whenever it can be agreed that evolution is solidly proved between two species, they must not be the same kind. This is an example of [[moving the goalposts]].
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To some extent, the same difficulty arises in biological taxonomy above the level of species (i.e. genus, family, order, class, phylum and kingdom, to use the classical [[Wikipedia:Linnaean taxonomy|Linnaean system]]). However, biologists have spent hundreds of years fine-tuning the system so that new species can be fit into the "tree of life" on the appropriate branch to a great degree of precision. The same cannot be said for sort of "Biblical taxonomy" suggested by the word ''kind''.
  
==External Links==
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Creationists do not agree with one another about exactly what "kind" means, and have never proposed a rigorous definition. They only seem to agree on the [[ad hoc]] sense that whenever it can be agreed that evolution is solidly proved between two species, they must not be the same kind. This is an example of [[moving the goalposts]].
  
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==External link==
 
* [http://www.talkorigins.org/faqs/comdesc/ 29+ Evidences for Macroevolution: The Scientific Case for Common Descent] at [[Talk Origins]]
 
* [http://www.talkorigins.org/faqs/comdesc/ 29+ Evidences for Macroevolution: The Scientific Case for Common Descent] at [[Talk Origins]]
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[[Category:Evolution]]
 
[[Category:Evolution]]

Revision as of 14:25, 24 October 2007

Macro-evolution and micro-evolution are terms that are sometimes used in a scientific context, but are more often thrown around by creationists to get around some of the instances in which evolution has actually been observed. The basic idea is:

  • Macro-evolution is evolution on a large scale.
  • Micro-evolution is evolution on a small scale.

Unfortunately, there is no clear dividing line between the "large" and "small" scales being referred to.

A problem of definition

A common creationist claim is that micro-evolution has been observed, but macro-evolution never has. In fact, if any type of evolution is actually observed, it is likely to be called micro-evolution simply because of that fact. Thus, in this sense, the terms have little use beyond anti-evolution apologetics.

In science, to the extent that the terms are used at all:

  • Micro-evolution generally means change within a species.
  • Macro-evolution generally means change between species.

The word species typically refers to a group of individuals that can interbreed with each other. So, for example, the huge variety of dog breeds that have resulted from hundreds of years of human influence would be an example of micro-evolution, since different breeds of dog can still interbreed (though it may be physically awkward in some cases). However, since dogs and foxes, for example, cannot interbreed, the split of the two species from a common ancestor was an example of macro-evolution.

Does this mean that speciation (a split of one species into two) cannot be directly observed? Certainly not. Speciation has been observed under laboratory conditions: scientists have successfully induced the evolution of new species that cannot breed with the original strains.

Biblical "kinds"

Because speciation is an observed phenomenon, creationists like to redefine terms by talking about macro-evolution not in terms of species but in terms of "kinds." But a kind is not a scientific notion, and creationists are notoriously vague when it comes to defining what it means:

  • Is a chihuahua the same "kind" as a Saint Bernard?
  • How about a chihuahua and a fox?
  • How about a wolf and a house cat? (They're both mammals, after all — and even in the same family, carnivora.)

To some extent, the same difficulty arises in biological taxonomy above the level of species (i.e. genus, family, order, class, phylum and kingdom, to use the classical Linnaean system). However, biologists have spent hundreds of years fine-tuning the system so that new species can be fit into the "tree of life" on the appropriate branch to a great degree of precision. The same cannot be said for sort of "Biblical taxonomy" suggested by the word kind.

Creationists do not agree with one another about exactly what "kind" means, and have never proposed a rigorous definition. They only seem to agree on the ad hoc sense that whenever it can be agreed that evolution is solidly proved between two species, they must not be the same kind. This is an example of moving the goalposts.

External link

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