That may be true, but as defined mechanisms of change they are not. Lets take your arguement and see how it applies to evolution.
It could be an easy to counter your arguement to point out that redefinition applies to any science. However, the changing definition of evolution over time has some interesting fodder for this discussion.
As defined, the one part of evolution that used to conflict with creationism has since been changed.
Evolution of a Definition
A god slayer evolution isn't, nor should be.
by Glen W. Wolfrom, Ph.D.
[Note: This information was taken from various sources, including Religion News Service stories and an Internet special report from the NCSE.]
The National Association of Biology Teachers (NABT) issued in 1995 their official "Statement on the Teaching of Evolution." Not surprisingly, it is blatantly anti-creation and pro-evolution in its message. One of the tenets was the following statement:
"The diversity of life on earth is the outcome of evolution: an unsupervised, impersonal, unpredictable and natural process of temporal descent with genetic modification that is affected by natural selection, chance, historical contingencies and changing environments."
This definition of evolution in terms of an "unsupervised" and "impersonal" process has been seized upon by creationists as further evidence that evolution is purely naturalistic and materialistic (i.e., it is godless). UC-Berkely law professor Phillip E. Johnson has been particularly effective in the last few years (with major books published in 1991, 1995, and 1997) in documenting this fact.
This brings us to the NABT annual meeting held October 8-11 in Minneapolis. At the board of directors meeting on October 8, a letter was presented from two "scholars" (a Notre Dame philosophy professor and a Syracuse University religion professor) who argued against inclusion of the words "unsupervised" and "impersonal." They maintained that:
"Science presumably doesn't address such theological questions ... How could an empirical inquiry possibly show that God was not directing evolution?"
These theistic evolutionists were obviously not arguing against evolution; rather, they suggested that using these two words "gives aid and comfort to extremists in the religious right for whom it provides a legitimate target." Further, they said that eliminating these two words would "help defuse tensions which, as things stand, are causing problems in our collective life."
However, after a nine-hour meeting the board voted against altering the statement. The executive director noted that changing the statement would give the creationists just the aid and comfort the scholars had argued against. However, the story does not end here.
NABT member Eugenie Scott (who is also executive director of the National Center for Science Education, NCSE, a watchdog group of anti-creationists) apparently urged the directors to reconsider, saying in a later interview that the change in wording was "a matter of staying religiously neutral." Just before the annual meeting was adjourned on October 11, the board reconvened and reversed its earlier vote.
Ms. Scott admitted that "it's no more proper to present naturalistic philosophy as valid science than it is to present religiously based arguments."...