Macroevolution - Macroevolution Confusions Ways in which...

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Macroevolution Confusions Ways in which the term "macroevolution" is used by scientists. Some are exact in the way they use it, while others are less exact. These usages are not all the same, and this causes some confusion. Why do scientists not agree on the meaning of their terms? The meaning modern authors give to the terms "macroevolution" and "microevolution" is often confusing, and varies according to what it is they are discussing. This is particularly the case when "large-scale" evolutionary processes are being discussed. For example, R. L. Carroll, in his undergraduate textbook ( 1997 : 10) defines microevolution as "involving phenomena at the level of populations and species" and macroevolution as "evolutionary patterns expressed over millions and hundreds of millions of years". Eldredge says, "Macroevolution, however it is precisely defined, always connotes "large-scale evolutionary change" (1989: vii) and throughout his book speaks of macroevolution as roughly equivalent to the evolution of taxa that are of a higher rank than species, such as genera, orders, families and the like. In his book Evolution , Mark Ridley defines the terms thus ( 2004 : 227): Macroevolution means evolution on the grand scale, and it is mainly studied in the fossil record. It is contrasted with microevolution, the study of evolution over short time periods, such as that of a human lifetime or less. Microevolution therefore refers to changes in gene frequency within a population . ... Macroevolutionary events events are much more likely to take millions of years.
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Macroevolution - Macroevolution Confusions Ways in which...

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