Macro-evolution vs. micro-evolution/adaptations is not a real distinction. They are a difference of degree and not kind.
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12]
Macro-evolution **
is** nothing but lots and lots of “micro-evolution”!** Such a point of view is simply untenable, and it denotes a complete misunderstanding of the nature of function. Macroevolution, in all its possible meanings, implies the emergence of new complex functions. A function is not the simplistic sum of a great number of “elementary” sub-functions: sub-functions have to be interfaced and coherently integrated to give a smoothly performing whole. In the same way, macroevolution is not the mere sum of elementary microevolutionary events.
A computer program, for instance, is not the sum of simple instructions. Even if it is composed ultimately of simple instructions, the information-processing capacity of the software depends on the special, complex order of those instructions. You will never obtain a complex computer program by randomly assembling elementary instructions or modules of such instructions.
In the same way, macroevolution cannot be a linear, simple or random accumulation of microevolutionary steps.
Microevolution, in all its known examples (antibiotic resistance, and similar) is made of simple variations, which are selectable for the immediate advantage connected to them. But a new functional protein cannot be built by simple selectable variations, no more than a poem can be created by random variations of single letters, or a software written by a sequence of elementary (bit-like) random variations, each of them improving the “function” of the software.
Function simply does not work that way. Function derives from higher levels of order and connection, which cannot emerge from a random accumulation of micro-variations. As the complexity (number of bits) of the functional sequence increases, the search space increases exponentially, rapidly denying any chance of random exploration of the space itself.
****13] Real Scientists Do Not Use Terms Like Microevolution or Macroevolution ****
The best answer to this claim, which is little more than an urban legend, is to cite relevant cases. First, textbooks:
(4th Ed.) *Biology *states: “macroevolution: Evolutionary change on a grand scale, encompassing the origin of novel designs, evolutionary trends, adaptive radiation, and mass extinction.” [By contrast, this book defines “microevolution as “a change in the gene pool of a population over a succession of generations”]
Futuyma’s
Evolutionary Biology, in the edition used by a senior member at UD for an upper division College course, states, “In Chapters 23 through 25, we will analyze the principles of MACROEVOLUTION, that is, the origin and diversification of higher taxa.” (pg. 447, emphasis in original). [Futuyma contrasts “microevolution” – “slight, short-term evolutionary changes within species.”]
In his 1989 McGraw Hill textbook,
Macroevolutionary Dynamics, Niles Eldredge admits that “[m]ost families, orders, classes, and phyla appear rather suddenly in the fossil record, often without anatomically intermediate forms smoothly interlinking evolutionarily derived descendant taxa with their presumed ancestors.” (pg. 22.) In
Macroevolution: Pattern and Process (Steven M. Stanley, The Johns Hopkins University Press, 1998 version), we read that, “[t]he known fossil record fails to document a single example of phyletic evolution accomplishing a major morphological transition and hence offers no evidence that the gradualistic model can be valid.” (pg. 39)
The scientific journal literature also uses the terms “macroevolution” or “microevolution.”
In 1980, Roger Lewin reported in
Science on a major meeting at the University of Chicago that sought to reconcile biologists’ understandings of evolution with the findings of paleontology:
“The central question of the Chicago conference was whether the mechanisms underlying microevolution can be extrapolated to explain the phenomena of macroevolution. At the risk of doing violence to the positions of some of the people at the meeting, the answer can be given as a clear, No.” (Roger Lewin, “Evolutionary Theory Under Fire,” Science, Vol. 210:883-887, Nov. 1980.)
**Two years earlier, Robert E. Ricklefs had written in an article in
Science entitled “Paleontologists confronting macroevolution,” contending: **
“The punctuated equilibrium model has been widely accepted, not because it has a compelling theoretical basis but because it appears to resolve a dilemma. … apart from its intrinsic circularity (one could argue that speciation can occur only when phyletic change is rapid, not vice versa), the model is more ad hoc explanation than theory, and it rests on shaky ground.” (Science, Vol. 199:58-60, Jan. 6, 1978.)
So, if such terms are currently in disfavor, that is clearly because they highlight problems with the Modern Evolutionary theory that it is currently impolitic to draw attention to. In the end, the terms are plainly legitimate and meaningful, as they speak to an obvious and real distinction between (a) the population changes that are directly observationally confirmed, “microevolution,” and (b) the major proposed body-plan transformation level changes that are not: “macroevolution.”