Macroevolution and microevolution

[otseng]

One of the points brought up before, and a key point in C vs E debates, is the difference between macroevolution and microevolution.

Both creationism and evolutionism believe in microevolution. There is no dispute that microevolution occurs.

But evolutionism believes in macroevolution, whereas creationism does not. This is the key point in the difference between C and E.

Here are some definitions:

Macroevolution

TalkOrigins

A term introduced by Theodosius Dobzhansky in 1937, referring to evolution at levels higher than the populational. Macroevolution in his view was evolutionary change at the level of speciation and above. Recently, the term has been used simply to refer to large scale change, mostly at the superspecies level, eg, by Niles Eldredge.

Hyperdictionary

Evolution on a large scale extending over geologic era and resulting in the formation of new taxonomic groups

Microevolution

TalkOrigins

A term referring to evolutionary changes beneath the level of the species. It includes, but is not limited to, adaptation to local environments. See also macroevolution.

Hyperdictionary

Evolution resulting from small specific genetic changes that can lead to a new subspecies

However, some evolutionists believe that there are no differences between microevolution and macroevolution.

So, is there a difference? Why or why not?

[otseng]

Greetings, all. I discovered this forum through a google advertisement on www.iidb.org, where I am administrator and moderator of our own EvC forum. I happen to be particularly interested in this debate topic, so I hope no-one will mind if I crash in here with a few half-baked thoughts.

Didymus, I just wanted to extend a welcome to you to our humble little forum. (I'm also glad to see my google ad attracting quality debaters).

[Didymus]

Well how kind. I'm sure we can find all sorts of interesting stuff to natter about. My interests are usually fairly constrained to biology but if the rest of this place is as generally pleasant as I've seen so far, who knows.

First one has only to settle on a definition of macro-evolution to debate. In my response I did say that if macroevolution is speciation, speciation is demonstrable.

Indeed, a definition is needed, but all too often this is an impossible ask. As you say, speciation is almost always a macroevolutionary phenomenon, but then on the other hand when someone who does not accept evolution claims that their problem is with 'macroevolution', they usually aren't thinking of the possibility or otherwise of a reproductive barrier arising in a drosophila population. Generally (and any evolution denyers who disagree must correct me if I'm wrong) the thing that's being rejected is the idea that humans came from apelike ancestors, that mammals and birds are descended from reptilian ancestors, and that all these ancestors themselves descended from unicellular progenitors. The term for this idea is common descent, which is as common and unambiguous as 'macroevolution' is nebulous and vague.

[otseng]

Generally (and any evolution denyers who disagree must correct me if I'm wrong) the thing that's being rejected is the idea that humans came from apelike ancestors, that mammals and birds are descended from reptilian ancestors, and that all these ancestors themselves descended from unicellular progenitors. The term for this idea is common descent, which is as common and unambiguous as 'macroevolution' is nebulous and vague.

Yes, the main point is the rejection of common descent. Would you mind starting a new thread to debate this?

[Didymus]

Yes, the main point is the rejection of common descent. Would you mind starting a new thread to debate this?

A new thread specifically to debate whether all organisms share common descent, is that right?

[otseng]

A new thread specifically to debate whether all organisms share common descent, is that right?

Correct. Also, as a note to those who don't know, you get an extra token for every post that anybody makes for a topic that you start. So, it's one nice way to accrue tokens.

[Mightor]

Mightor say microevolution + time = macroevolution.

Mightor say these terms worthless. Is all evolution. Mightor say puny humans hear more puny creationists use these terms than puny biologists because is divisive.

[Illyricum]

Mightor, if you want people to take you seriously, than I suggest that you act seriously.

[Mightor]

Mightor, if you want people to take you seriously, than I suggest that you act seriously.

Mightor say read your own sig. Mightor dead serious.

[Didymus]

Actually, as I pointed out earlier, macroevolution is currently used to refer to qualitatively different phenomena than can be explained by microevolution + any amount of time. Most of them are extremely important and interesting concepts that could well be completely overlooked if they weren't classified in this way.

Furthermore, biologists, particularly those in fields relevant to evolution, use the term constantly. In fact, no textbook on the subject fails to devote huge chunks of its volume to macroevolution. And there are, of course, massive tomes devoted entirely to macroevolution such as Levintons 'genetics, paleontology and macroevolution' - 617 very full small-print pages devoted entirely to the subject. Other big names writing whole books or texts on macroevolutionary topics include Peter W. Price and Mary Jane West-Eberhard, no less.

Of course, (as I also pointed out already), the modern biological use of the term is not very similar to the popular one. Common descent is what really comes under debate by laymen, and I started a new thread about that recently, as requested.