What's the difference between macro-evolution and micro-evolution?

Answer 1

Microevolution is defined as evolution at or below the species level.

Macroevolution is defined as evolution at or above the species level.

Speciation can be considered part of either microevolution or macroevolution ... so there is obvious overlap.

As for whether it is "short-term" vs. "long-term" ... microevolution is *usually* associated with "short-term" changes (within a few dozen to several hundred generations or so ... as long as the descendant is not considered a "new species") ... but that means that "short-term" can mean tens of thousands of years for some slow-breeding species (like humans). And macroevolution is usually associated with "long-term" evolution, but as speciation can occur in some very fast-reproducing species like fruit-flies in as little as a dozen or so generations, "long-term" can mean as little as a few years. So it's hard to pin down a difference between "short-term" and "long-term" ... even in terms of generations.

There is also no firm division between where microevolution "ends" and macroevolution "begins". You would think that this at the moment of speciation ... but it is even difficult to pinpoint when this occurs. Even consider a species evolving over time ... at some point the descendant species has enough differences from the ancestor species that they would generally be called different species (i.e. microevolution has produced macroevolution). Sometimes the differences are just enough that some biologists still call them the same species, while others would disagree. And even when branching occurs (the defining moment of speciation), there is still a period where some hybrids might still be fertile enough to keep the species consistent.

For all these reasons, it's *really* important to remember that this distinction between microevolution and macroevolution is just one made for purposes of the *study* of evolution ... it is not a difference in *nature* itself ... there is no "dividing line" between the two. Microevolution is *usually* easier to examine using experiment (because it is *usually* short-term enough that the process occurs within the lifespan of a human scientist), while macroevolution *usually* is examined using *observation* (rather than experiment) because it *usually* occurs over thousands to millions of years ... but first, that is not always the case, and second, observation is just as legitimate a way of doing science as experiment.

In other words, it's like the difference between "microbiology" and "macrobiology" ... the main difference is that microbiology needs a microscope ... but this is just a difference in the way we *study* it, not a division that has any significance in nature.

This is the error made by creationists (perhaps deliberately, as an effort to *confuse*). They have taken a legitimate term ... a conceptual distinction for purposes of *study* ... and twisted its meaning in a very non-scientific way, to suit a specific agenda.

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P.S. The length of my answer (and of the two sources I list) is a great example of why creationists make teaching biology three times harder. What could be a very short and simple answer, has to be three times longer because it has to clear up a lot of creationist misinformation about a topic. The same applies to words like "theory", "fact", "evolution", "mutation", etc. Every explanation we give has to be 3x longer that it should be ... just to pre-empt creationist *misinformation* about these terms.

That's one reason so many students find biology (or evolution) "confusing." Creationsists are doing *such* a great service for science education.

Answer 2

In actually evolutionary biology micro-evolution means variation within a species (for example brown eyes and blue eyes) and macro-evolution is variation between species. For the most part it is not necessary to make a distinction since you're analogy is quite correct there is no objective barrier between the two. Macro is just a lot of micro if I can walk 20 feet the same process will take me 20 miles given enough time. Creationists use the terms differently. To them micro-evolution is "adaptation" or variation within "kinds". Where macro-evolution is one "kind" changing into a different "kind". Of course if you ask them what exactly a "kind" is they will change the subject.

Answer 3

micro-evolution is normal genetic variance that occurs within a species, for instance in humans it is possible to have blue or brown eyes... in a hypothetical situation, a toxin is released that kills all brown-eyed people and all the blue-eyed people survive. There is suddenly a reduced frequency of brown-eye genes in the population, and only blue-eyed people can propagate because they survived. Microevolution has occured. (Usually this is less drastic, such as a bird's beak shape favoring survival under conditions of relative abundance of a certain type of feed, etc.... but the example works.)

Macroevolution can be thought of in terms of not changes within a species, but emergence of an entirely new species as a result of other smaller-scale evolutionary changes. Such as, evolutionary adaptations that may have favored development of a turtle from a lizard... or some such example.

Answer 4

They're basically defined as micro-evolution being simple changes in genotype while macro-evolution is a lot of small changes over a longer period of time that gives substantial variation from the original organism.

Put simply:

Micro: small changes over shorter time
Macro: large changes over longer time.

Additionally, a lot of religious nuts will tell you that macro evolution is impossible. Please don't fall for it, there is nothing to prevent small changes accumilating over time into large changes.

Answer 5

the dude aboves got it mixed up

Micro evolution is changes in a gene pool over a long period of time EX color size

Macro evolution is when the changes in a organism are significant enough to make it a new species.

for more information go to my link im just summing your question up