Re: Peppered Moths - in black and white

Kevin O'Brien (
Fri, 2 Apr 1999 11:58:47 -0700

>Kevin O'Brien wrote:
>>It is not a matter of being wedded to anything; "microevolution" is
>>legitimate evolution, as Darwin established and subsequent research has
>>continuously demonstrated.
>Does this temporary change in allele frequencies really satisfy your
>wish to know how evolution occurred? Is it fair to call it an example of
>how complex organisms evolved?

Yes to both, because any new organism created by some "macroevolutionary"
mechanism must still successfully interact with its environment to survive
and propogate; this involves natural selection. Also, virtually any
"macroevolutionary" mechanism would have to use such "microevolutionary"
mechanisms as gene duplication and mutation to operate; this would thus
produce a change in allele frequencies, which is the definition of
evolution. Any kind of gross morphological change must be accompanied by
genetic changes, which are the same kinds of changes we see in such
scenarios as the peppered moth and the recently documented changes in the
beak sizes of Galopogos finches, not to mention such scenarios as antibiotic
and pesticide resistence. By understanding these temporary changes we
better understand the "permanent" changes, because the same mechanisms that
govern these temporary changes also govern the "permanent" changes as well.

It should, however, be pointed out that as Don Frack explained, no gross
morphological change is truely irreversible. Some morphological changes
that reverse do so because the genes that control them revert to their
original frequencies, but this only happens when the underlying genetics is
fairly simple. Gross morphologies that are based on more complex genetic
changes can still appear to reverse, but in those cases the original genetic
changes do not reverse. Instead, new changes either eliminate the old
changes or work cooperatively with the old changes to revert the gross
morphology. This is called a phenotypical reversion, because the phenotype
(the morphology) of the organism has reverted to "wild type" but the
genotype (the genome) of the organism has not. (Subsequently, the peppered
moth would be an example of a genotypical reversion, one in which the
genotype itself reverts.) The point is that no evolutionary change need be
permanent, if there is a way to revert it, either phenotypically or

It should be pointed out also that a phenotypical reversion need not involve
a complete reversion back to original structures; it can in fact involve the
creation of new structures that create a morphology that appears
indistinguishable from the old morphology using a gross examination, but has
significant underlying differences. Don Frack's example of the shark fin
versus the whale flipper is an excellent example of this kind of
phenotypical reversion.

>>True, but by restricting any discussion of evolution in general to
>>"macroevolution" they hope to eliminate the clear evidence based on
>>"microevolution" that evolution is a real phenomenon and instead force all
>>debate into an arena where they think there is no evidence to support
>There may be no direct evidence of macroevolution; but it's not logical to
>dismiss it. Macroevolutionary theory is necessary to save evolutionary
>theory; it's not a creationist plot.

No, no, you keep missing the point. Let's step back a moment. First of
all, the distinction between "microevolution" and "macroevolution" is a
false dichotomy. It was originally used by some evolutionists as a casual
(i.e., not scientifically rigorous) way to distinguish between evolutionary
change like we see in the peppered moth and evolutionary change like we see
in speciation and beyond. These terms were never meant to be an official
division of evolution into two separate types, and those who promoted them
as a convenience were also quick to point out that "macroevolutionary"
change is still dependent upon "microevolutionary" change, thus reaffirming
for their colleagues that "micro-" and "macroevolution" were really all one
and the same under evolution as a whole.

At that time, mainstream creationists were claiming that there was no
evidence for natural selection or speciation, so they didn't care about this
convenience; they were claiming that evolution as a whole was false. Later,
however, when they began to realize that there was enough evidence to
establish natural selection and speciation as facts, and that they were thus
in danger of loosing the war to the evolutionists, they switched tactics.
They started claiming that natural selection and speciation were true, that
they had always believed it, but that these were simply examples of natural
variation within a species, not evolution. That's when they adopted the
terms "microevolution" and "macroevolution", to try to argue that there were
actually two separate kinds of evolution, one that governed variation and
one that governed increases in complexity (to use "Cummins" choice of
words). Whereas the evolutionists who first developed these terms used them
as labels of convenience, the creationists began to use them as if they
represented separate phenomena that had little or no relation to each other.
In this way they hoped they would be able to isolate the "microevolutionary"
evidence that demonstrated that evolution as a whole was a fact from the
debate by shifting the debate to "macroevolution", which they felt had
virtually no evidence to support it. In this way they hoped to still
"prove" that evolution was impossible without looking so foolish as to deny
the clear fact of "micro" evolutionary change.

This tactic has in fact been so successful that even many contemporary
evolutionists believe the false dichotomy. This tactic makes it possible
for creationists to deny the classical definition of evolution as well as
the clear evidence that demonstrates evolution as a whole is a fact while
they demand proof of "macroevolution", proof they believe can never be
found. It has even gotten to the point where they are dropping the old
"micro" and "macro" prefixes and are using "variation" in place of
"microevolution" and reserving "evolution" for "macroevolution", thus
finalizing the false division of evolution into two separate unrelated
phenomena. If evolutionists in turn begin to accept these new labels, the
creationists will have succeeded in redefining the debate to their advantage
as well as giving themselves a new lease on life, when they should have been
defeated a decade ago.

No, this is not a concious plot, though the decision to use the false
dichotomy and to claim to accept "microevolution" as true were conciously
made. However, you can prove to yourself that this shift in tactics has
occurred, though it will take some work. All you have to do is read
creationist literature, including discussion group posts like these, for the
last three decades to see this shift in their writings. Meanwhile, there is
of course lots of evidence that establishes "macroevolution" as a fact, but
this evidence is more difficult to explain and requires a greater expertise
in various sciences to fully appreciate, unlike peppered moths. This,
coupled with the new emphasis on "biological information", "complexity" and
the attacks on abiogenesis, in turn makes it harder to demonstrate how
creationist arguments are wrong and how evolution is a fact.

The bottom line, though, is that "macroevolution" is not necessary to "save"
evolution; "macroevolution" combined with "microevolution" ARE TOGETHER BOTH
evolution as a whole. They are one and the same, so that the "micro"
evidence which shows that evolution is real also demonstrates that
speciation and beyond are also real.

Epilogue: To avoid the inevitable question regarding mechanisms, I need to
point out that evolution as a whole does involve a number of different
mechanisms that operate at different stages of evolutionary development.
These mechanisms, however, are not mutually exclusive and they do not
operate independently. As such, a ("macro") mechanism that may utilize
changes in the genes that control development would still have to work
cooperatively with the ("micro") mechanisms of gene duplication, mutation
and natural selection to create a new viable organism, otherwise it would
fail to survive and propogate itself.

Kevin L. O'Brien