Is macro evolution the cumulative result of micro evolution?

Question

Does most speciation occur gradually, or is there a major "leap" at the point of speciation?
I am confused when creationists say they accept microevolution but reject speciation-- it seems like enough small changes would result in speciation eventually... am I wrong?

thanks for explaining what macroevolution means scientifically, vorenhutz. I thought it was just another word for speciation.

Answer 1

vorenhutz hit it beautifully.

A key point is that this is a distinction of *focus* as far as human scientists looking at nature ... but it is NOT a division within nature itself. Microevolution *usually* (but not always) involves "short-term" evolutionary change that can be seen, in some species, within a few generations, and thus can studied using direct experiment. Macroevolution *usually* (but not always) involves much longer-term evolutionary changes that take hundreds to thousands of generations, and thus thousands to millions of years, and thus is more appropriately studied through observation of evidence (such as genetic evidence, fossils, morphological structures, etc.).

However,
(1) this is not a firm distinction (some microevolutionary changes take millions of years to manifest, while some macroevolutionary change ... such as speciation ... can occur in time periods occuring in the lab with certain fast-reproducing species (like fruit-flies)); and;

(2) Observation is absolutely just as legitimate a method for doing science as direct experiment. There are entire sciences built upon observation ... astronomy, astrophysics, geology, long-term climatology, meteorology, paleontology, archaeology, anthropology, and large parts of theoretical physics.

I liken it to terms like 'microbiology' and 'macrobiology' ... the only difference is that the former uses microscopes ... there is no firm division IN NATURE between the two.

As far as speciation, that can either be considered part of microevolution or macroevolution depending on your viewpoint. Creationists who reject speciation, are just not up on the science. Speciation has been demonstrated *in nature*, and reproduced *in the lab*. (See sources.) As such, by equating (wrongly) speciation with macroevolution ... they have set themselves up for the fact that macroevolution itself has been demonstrated in nature and in the lab. (I.e. it was a bad strategic move to draw the line in the sand there.)

Answer 2

> Is macro evolution the cumulative result of micro evolution?
It appears so. It's the best explanation we have, certainly.

> Does most speciation occur gradually, or is there a major "leap" at the point of speciation?
In animals, gradually. Plants, with their polyploidy and self-fertilization, are more likely to make a sudden change.

> it seems like enough small changes would result in speciation eventually
Yup, correct. That does appear to be the way it happens.

Answer 3

Because species that microevolve can still mate with the same species, and any other evolution would have the problem of not having anything to mate with. Theres alot of gene theory invovled, and I definately see where you're coming from. The truth is, we can either go with books written by people who wittnessed something and didnt understand alot about the world,, and got some historical things right, or we can go by a bunch of people who basically made really educated guesses and have alot of theories. Both are very flimsy. It's up to you and what you think is right. And, by the by, theres alot more then timescale that seperates them. But that would take many hours and sevral books to explain. In the end, evolution still doesnt explain how we got here, and the big bang theory has finally been revoked. Its an insult to scientists and theorists...

Answer 4

perhaps you're confused because creationist usage of the word macroevolution has little relationship with scientific usage. to the creationists it apparently means 'that degree of change that has not been directly observed'. because they are skeptical of any conclusion that involves the slightest amount of theoretical inference from evidence, they naturally don't believe in "macroevolution".

macroevolution in scientific usage though is the pattern of evolution - common descent and large changes of form, things like the origin of flight. macroevolution isn't even about mechanism, it's about pattern (obviously there are mechanisms involved, but questions about macroevolution are questions about pattern, not mechanism).

speciation is a different thing again, it is the generation of new species (in evolutionary theory, it is generation from ancestor species rather than the creationist "model" of spontaneous generation, aka "magic"). as you point out, there is nothing to prevent speciation from happening by accumulation of small changes - the species eventually changes so much that we call it a new species (anagnesis), or sometimes it can be relatively sudden, due to migration or environmental changes (cladogenesis).

Answer 5

You're not wrong at all. Microevolution leads to macroevolution.

There is some disagreement as to how quickly it happens. Proponents of the idea of gradualism believe that changes (and new species) accumulate slowly, over great periods of time. People who favor the idea of punctuated equilibrium believe that bursts of speciation occur in relatively short periods of time, followed by long periods of stability. But regardless of what either camp believes, both accept the reality of evolution.

Answer 6

Those are terms coined by creationists in an attempt to reconcile evidence of change with their religious beliefs. The creationist position sometimes is that change can happen within a particular "kind" of creature, i.e. a dog, but that what they call macroevolution does not happen. This contradiction with evolutionary theory is justified in their mind by the lack of fossils of transistion species. This is flawed logic AND a misunderstanding of fossils, but that's another story.

To a scientist, its just evolution.

Answer 7

No - you're not wrong.
Macroevolution is anything above the species level, whereas micro is below it. Accounting for this - it seems almost common sense to realize that *most* changes below the species level should have *some* affect above it as well.
Whether it's additive or not depends on the two situations and the complexity of the relationships between the two levels.

Answer 8

I am among those seemingly shirking number of biologists who do not use the terms, " micro " and " macro " evolution. I was trained by those of the synthesis and they always referred to the seamless process of evolution and speciation.