What's the distinction between microevolution and macroevolution?
Traditionally the distinction is supposed to be at the species level. Micrevolution involves evolutionary changes within a species, while macroevolution involves evolutionary changes beyond a species. Such as when one species becomes another species. Or one species becomes two species (speciation).
- Yet, today, many scientists disagree with how to define a species. What, precisely, makes a species a species?
- Also, why is the focal point of macroevolution at the species level? Why is species where we draw the line between microevolution and macroevolution? After all, isn't evolution supposed to be akin to climbing Mt. Improbable? If so, then evolution is simply a gradual but continuous series of changes in one direction (give or take). Hence, why couldn't the line be drawn elsewhere?
- In fact, is it even a line so much as an outline or sketch? A fuzzy boundary?
- Moreover, aren't there multiple blurred lines?
- As such, the traditional demarcations between microevolution and macroevolution seem to overemphasize the significance and roles of species and speciation.
- Yet, if the borders are hazy enough between microevolution and macroevolution, then that could potentially affect the theory of evolution as a whole. After all, of what use are concepts like microevolution and macroevolution if the borders are so hazy? We might as well simply call microevolution "small change" and macroevolution "big change" for all the explanatory power these terms have.
- Macroevolution is supposed to be reducible to microevolution. Macroevolution is supposed to be the accumulation of small genetic changes over time (microevolution). Macroevolution is a continuous spectrum of microevolutionary changes.
All this requires genetic changes. How do genetic changes occur? There are several ways, but the primary driver of these small genetic changes is supposed to be random mutations. In addition, these genetic changes can't be deleterious mutations, or even neutral mutations, but they must be beneficial mutations, in order to drive phenomena like speciation. However, the vast majority of mutations are not beneficial mutations. And according to mathematicians, the problem isn't solved even if given hundreds of millions of years to work with.
> "Traditionally the distinction is supposed to be at the species level."
ReplyDeleteAccording to whom? I've often read evolutionists projecting this belief onto creationists (for the purposes of the next move, of finding fault); but can't recall ever reading a respected creationist who takes this position. That's because it's a position that falls apart instantly. Plainly the "species" level in the Linnean taxonomy is not the Genesis "kind", since there are different species which can inter-breed. Such species, at least, must be the same "kind".
"According to whom? I've often read evolutionists projecting this belief onto creationists (for the purposes of the next move, of finding fault); but can't recall ever reading a respected creationist who takes this position. "
DeleteI think you answered your own question! I'm simply rehearsing the standard view from the perspective of the evolutionist. If you want more, the most common view is Ernst Mayr's BSC.
"That's because it's a position that falls apart instantly. Plainly the "species" level in the Linnean taxonomy is not the Genesis "kind", since there are different species which can inter-breed. Such species, at least, must be the same "kind"."
Of course I agree with the criticisms inasmuch as I'm quite skeptical about neo-Darwinian fundamental concepts and neo-Darwinism as a whole. I've written a lot in the past and present which casts doubt on neo-Darwinism.