RufusAtticus

All the distinctions I've encountered, are simply artifacts made my humans. For instance on distinction between macro and microevolution is the scale at which we look. Microevolutionary differences are those between closely related individuals and macroevolution differences are those between distantly related individuals. That operational difference arrises two different methods of studying the diversity of life: compare similar organisms and study their differences, compare dissimilar organisms and study their similarities.

pz

Have you read Gould's Structure? Open with me to pages 717-719 (about halfway through the book!). That's a 3 page table in which he lists all the differences between micro and macro evolution, which he characterizes as evolution at the level of the organism vs. evolution at the level of the species. It is not an artificial distinction to say that death of an individual and extinction of a species are different processes, yet death and extinction also have comparable roles in micro and macroevolutionary processes, respectively.

RufusAtticus

pz, I have it on the shelf beside me. I'm going out to eat with the misses and reply later tonight.

RufusAtticus

Sorry, but I don't think Gould's ideas of "species selection" classify as macroevolution. It all comes back to the fact that different fields use the term differently. I won't bother to repeat my discriptions again.

I disagree; death is death, whether it is a single individual dying or a group of them dying.

Lobstrosity

I disagree with this disagreement. The evolution occuring at the individual level does couple in non-trivial ways to produce macroscopic changes that are more complex than simple the sum of the parts. More simply, I do not think it's a fair assessment to say that the principle of superposition holds when refering to evolution beyond a simple first-order approximation of the phenomenon. I like to think of macroevolution as akin to statistical mechanics. Though the effects of statistical mechanics are driven by microscopic molecular interactions, these interactions macroscopically couple in non-trival ways to produce observable trends that are important to our understanding of physics as a whole. Furthermore, one could never produce these trends by trying to just add up all of the microscopic interactions as the problem simply becomes too complex to solve. Complex problems cannot always be tackled by complete reductionism, asserting that one need only look at the most basic root cause of a phenomenon. Though "microevolution" drives all evolution, its course is sculpted by both intra- and inter-population interactions in ways scientists should be interested in characterizing. To me these characterizations would be "macroscopic" evolution, but then again, I'm talking out of my ass here so what do I know.

Vorkosigan

I am on the "no difference" side of this divide, but I don't have Gould. Does his definition involve his understanding of evolution as a "fits and starts" process that proceeds by jerky steps?

Vorkosigan

pz

He certainly doesn't phrase it that way.

His explanation is based on part that punctuated equilibrium emphasizes stasis in species, which means that we can treat them as coherent actors in higher level interactions. The most accepted modes of speciation, either allopatric in its various flavors or sympatric, all propose that populations and species compete with each other at some point in their histories -- the only mode that would contradict it is anagenetic change, which is almost certainly rare. Basically, he's saying that there is another level of evolution at the species level that is documented in the fossil record, but which has been poorly analyzed.

pz

I don't see the objection. Gould has given an internally consistent and useful definition of micro and macro evolution. That there are poor definitions floating around is indisputable, but there are also poor definitions of evolution as a whole around, that doesn't mean it is nonexistent.
And chemistry is chemistry, whether its going on in a flask or a cell. That doesn't mean that the phenomena biologists study are indistinct from what chemists do.

Principia

Ugh. You and Malachi are taking this debate to a completely unscientific, pseudo-philosophical level. The topic as stated is asking if there's an ontological difference between microE and macroE. What you and Malachi end up talking about is there is an epistemological utility in distinguishing between micro- vs. macro-evolution. My beef is that you guys rushed into this without even agreeing on what to debate. Take Malachi's initial salvo. It's substanceless rhetoric, most of which does not even come close to your take on the subject. Furthermore, he's picked a set of definitions before you did -- now what? You guys are simply going to duke out which of your definitions is better? On what criteria?

My prediction: you guys will end up talking past each other, and the debate is wasted.

PS: Color me cynical -- but this is why I strongly disagree with 1 on 1 debates with IDiots/Creatos anyways.

RufusAtticus

You've missed my point. Gould's table doesn't really address my point because he has a different view of what macroevolution is than I do. Therefore, when I say that the distinctions between macroevolution and microevolution are artifacts, I'm refering to the divisions as I and for the most part other populaiton biologists recongnize them.

Just for the sake of the lurkers:

Evolution is the change in the characteristics of populations of organisms over time.
Microevolution is evolution apparant within a species.
Macroevolution is evolution apparant between species.

Of course there is a lot of distinction between the study of chemistry and the study of biology. Just as there is distinction between the study of macroevolution and the study of microevolution. However, that doesn't mean that distinctions aren't artifacts resulting from how we study them.

But how is the death of a species distinct form the cummulated death of the individuals belonging to that species. The distinctions that Gould is making are simply artifacts of his decision to treat them as the unit of study. Similar artifacts occur when one pulls a Dawkins and goes the other way.