mountain_hare

After all of my debates against creationists, I am still clueless about the difference between microevolution and adaptation?

From a foe in another forum...

Notice how he capitalizes the term. It appears that he is saying that because microevolution = adaptation, it is no big deal.

Does all evolution result in adaptions? Or is adaptation a process? GRRRR. Stupid semantics!!!

Steinsky

An adaptation is a bit of anatomy or physiology etc, microevolution is the process.

But I know biologists who also use adaptation as a verb, so you can't really blame the foe this time.

Jet Black

adaptation is regarded as the changes in an organism over it's lifetime in order to better cope with its environment. for example if you take up a job as a lumberjack, your hands will become calloused and you will develop muscles like arnie. This is the result of the bodies reaction (based on genes) to the environment. Now adaptation does not result in any genetic change, and cannot be inherited. evolution however is the change in ratio of alleles in the population, and is a result of the environmental effects on phenotypical traits that arise as a result of the genotype. For example your genes might allow you to survive a diesease, or perhaps allow you to become muscular more rapidly, so no, micro-evolution is categorically not adaptation.

N.Wells

An adaptation is a modification that offers an obvious benefit, an improvement that is easily explained by natural selection. Microevolution is a more formal and more inclusive term that includes additional types of change, not only beneficial mutations, but also selectively neutral and even disadvantageous mutations (bearing in mind that "advantageous", "disadvantageous", and "neutral" are dependent on the organism's ecology & environment, etc., which may change). Microevolution also includes changes in gene frequency without innovation (e.g. the founder effect & genetic drift).

Creationists like to make a big deal of distinguishing micro-evolution from macro-evolution, with the goal that micro-evolution is just plain, old, every-day adaptation (not evolution, no serious innovation, no new species created), whereas macro-evolution is innovative change that results in new taxa at significantly elevated taxonomic levels, which they view as entirely theoretical. They want to accept evolution at the "baramin" level (whatever that is - close to humans, it's at the species level, but by the time you get as far away as insects it seems to have risen well above the level of orders).

Many biologists have talked about differences between lower-level evolutionary change versus higher level change, and whether different processes are involved at different levels or not. Some have used the terms micro and macro-evolution, but "macro-evolution" is a very flexible and informal term, and does not have a consistent, uniform, widely accepted definition. At least some high-level evolutionary change, if not most, seems to be just "micro", continued for a long time, but there are certainly many other interesting possibilities, such as mutations in the homeobox gene sequence, causing major, instantaneous, coadapted changes resulting from changes in the rate and timing of development of different features in the growing organism.

Edited to add: in common parlance, "adaptation" can have a Lamarckian connotation (as Jet Black just noted), but it can certainly be used to talk about evolutionarily or genetically caused changes in morphology, behavior, physiology, and so forth.