th1bill #fundie

th1bill #fundie baptistboard.com

Originally Posted by webdog
I think there needs to be clarification on what is termed evolution. Micro evolution is a scientific fact, macro evolution is the silly darwinism theory.

In the reading of the OP you will find that I did just that. I'll go one step further, when I was a junior high student, what you call Micro Evolution, was known by the term of Adaptation. The act of redefining Adaptation to lend some path down to slide into Darwin's theory is just a cheap trick of the Revisionist culture of today.

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old comment by David B.

@A Pedant: "Who should I be blaming for the spread of this so called difference between "macro" and "micro" evolution?"

That would be Ernst Meyr...

"Among all the claims made during the evolutionary synthesis, perhaps the one that found least acceptance was the assertion that all phenomena of macroevolution can be reduced to,' that is, explained by, microevolutionary genetic processes. Not surprisingly, this claim was usually supported by geneticists but was widely rejected by the very biologists who dealt with macroevolution, the morphologists and paleontologists" (Toward a New Philsophy of Biology, 1988).

...and Theo Dobzhansky.

"Nothing in the known macroevolutionary phenomena would require other than the known genetic principles for causal explanation" (Genetics and the Origin of Species, 1951).

"The only people who ever use it are those who deny that evolution happens but cannot bring themselves to ignore the vast evidence of evolution in short life-span lifeforms such as bacteria."

People like Nick Matzke and Eugenie Scott perhaps?

"In evolutionary biology, microevolution refers to evolutionary processes operating within a species. Although scientists sometimes colloquially refer to macroevolution as “evolution above the species level,” this definition does not do justice to the complexity of topics included within the concept. Macroevolution refers to patterns that emerge as species and lineages branch through time, including the rate and pace of evolutionary change, adaptive radiation, morphological trends in lineages, extinction or branching of a lineage, concepts such as species sorting, and the emergence of major new morphological features (such as segmentation, or shells, or the fusion or loss of bones)" (PNAS 104:8669-8676 (May 2007)).

Or Katzourakis, Gifford, et al?

"Macroevolution of Complex Retroviruses. [...] Our analysis highlights the role of evolutionary constraint in maintaining viral genome structure and indicates that accessory genes and mammalian mechanisms of innate immunity are the products of macroevolutionary conflict played out over a geological time scale" (Science 325:1512 (September 2009)).

Or David N. Reznick and Robert E. Ricklefs?

"Evolutionary biologists have long sought to understand the relationship between microevolution (adaptation), which can be observed both in nature and in the laboratory, and macroevolution (speciation and the origin of the divisions of the taxonomic hierarchy above the species level, and the development of complex organs), which cannot be witnessed because it occurs over intervals that far exceed the human lifespan" (Nature, 457:837-842 (February 2009)).

old comment by Reverend Jeremiah

AH.. The Baptist Board..where all TRUE Biologists go to get their study material.

P.S. there is only ONE evolution. By saying "micro" evolution exists, you are DEFAULT saying that evolution exists. Can you not see that? Can you not taste the bitter hypocrisy of your own words? You are basically saying that walking is VERY possible, and walking a mile to the store is scientific, but walking 100 miles is impossible. If you accept "micro" evolution, then how many "micro" evolutions do you need to get a "macro" evolution? One? A hundred? A million? If something has "micro" evolved once, then that species has evolved by decent with modification.. the EXACT definition of Darwins theory of natural selection.

old comment by Alencon

Microevolution and macroeolution are both valid scientific terms. Microevolution refers to changes within a species and macroevolution refers to changes at or above the species level.

However, and this is the big however, the processes are the same. Subject two offshoots of the same initial species to enough microevolutionary changes and they will become seprate species distinct from the original species. At that point macroevolution is considered to have occurred.

Creationists seem to believe that the processes are different when they are not. To say that microevolution occurs but macroevolution does not would require some barrier preventing speciation. No such barrier is known to exist. Perhaps the creationists might tell us what they think it is.

old comment by David B.

@A Pedant: "(I)t seems that only creationists view micro- and macro-evolution as wholly distinct phenonema rather than as two aspects of the same process, with one being a part of the other. The implication being, as Doubting Thomas rightly points out, that macro-evolution requires the existence of crocoducks."

Very much so. As Matzke and Scott put it, in the same paper referenced earlier:

"Decades ago, creationists began to use microevolution and macroevolution idiosyncratically. Creationists' use of “microevolution” is not dissimilar to that of evolutionary biologists, although they apply it not just to species but to evolution within the limits of a specially created “kind” of organism. When ID supporters and other creationists claim to accept some evolution, they generally mean it in this limited sense of evolution “within the kind.” A larger distinction occurs in the creationist definition of macroevolution, which to them refers to (unacceptable) common ancestry of different created kinds. It also refers to the acquisition of major morphological features or body plan changes, also considered impossible without the direct involvement of God. Both creation science and ID approach the micro/macro divide similarly: microevolution is accepted, and macroevolution (their definition) is rejected."

Creationists might regularly abuse the terms, but they were not smart enough to invent them.

old comment by David B.

(Paraphrasing) "There's no such thing as macro-evolution, it's all micro-evolution."

No, there's a technical difference between micro-evolution, which refers to evolutionary processes operating within a species, and macro-evolution, which refers to patterns that emerge as species and lineages branch through time, including the rate and pace of evolutionary change, adaptive radiation, morphological trends in lineages, extinction or branching of a lineage, concepts such as species sorting, and the emergence of major new morphological features (such as segmentation, or shells, or the fusion or loss of bones) [to quote Nick Matzke again].

While "microevolution + time = macroevolution" is generally true, it is a very broad and imprecise statement. Not all "microevolution + time" leads to macroevolution (i.e. morphological change), as the very long lineages of some species and the existence of living fossils shows. Nor even is all macroevolution a product of "microevolution + time", since there are several known instances of new species emerging from hybridisation of existing ones (many of the examples of observed macroevolution listed on the talk.origins site are of this type). These are cases where the 'evolution' took place above the species level, and it was not a result of the accumulation of small changes over time. Hybridisation is even thought to have played a part in our own evolution.

A second problem with claiming all macroevolution is just microevolution plus time is evidence. We frequently infer "macroevo" from fossil lineages (which we have lots of, hence we win), and can do so with enough accuracy to predict where an when specific intermediates occurred, hence identify the best places to look for them. However we can't show what microevo was responsible for these changes, DNA doesn't fossilise and while parsimonious genetic trees can help confirm common descent in living species they are no help for extinct ones.

So while it is generally okay to say that "microevolution + time = macroevolution", the two terms are not (IMO) exactly synonymous.

It's all evolution, but it's not necessarily all microevolution.

Nice reference:
"Hybridization, ecological races and the nature of species: empirical evidence for the ease of speciation"
- James Mallet, Philosophical Transactions of the Royal Society, September 2008, 363:2971-2986 (available online).

th1bill #fundie baptistboard.com

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