Although a
post of this nature is perhaps best discussed in the
talk.origins newsgroup, I'll
take a stab at your comments, though I'll invite Larry
Moran to correct me or put in his own two cents as he sees
fit.
It is true that evolution is not defined in the Evolution is a Fact and a
Theory FAQ. It is, however, defined in the What is Evolution?
FAQ, also by Mr. Moran. It is defined by biologists as
any change in the frequency of alleles in a population over
time. As we observe genetic change taking place, it is hard
to classify it as anything but a fact.
To explain why allele frequencies change, we have
theories of evolution. Those theories include mutation and
natural selection. They also include common descent,
genetic drift, gene flow, and other theories. What you are
objecting to, I suspect, is the theory of common descent,
the idea that all current life on Earth originates from
common ancestry. This is a part of evolution, and an
important part, but only a part.
You provide no indication why defining evolution in this
manner makes it unable to "explain anything beyond the
species level." Indeed, I see no reason for such an
assumption. We know that speciation takes place, as we have observed it.
Higher taxonomic classifications are man-made conveniences,
artificially imposed by us humans. We know that small
changes can add up to large changes. No one has yet to
propose a reasonable barrier to diversification. I'm not
sure what else is required.
I can't judge the quotation you provide, not knowing its
context. However, I suspect that Medewar was trying to
explain that in science, nothing is 100% proven. In
mathematics or logic, statements can be proven true or
false given a particular set of initial assumptions and
rules for deriving new statements. But in science, proof
means much the same thing as it does in law. Evidence is
amassed to support or contradict a proposition, and the
proposition is "proven" or "disproven" once the weight of
the evidence falls one way or the other. Even the most
tested and solid theories in science could be wrong,
just as the man found holding the smoking pistol over the
dead body could be innocent, but at some point we
have to say there is enough evidence to accept it as true.
(Actually, confirming a major theory in science requires
much more evidence than we use to convict people of
crimes.) By this meaning of "proof," the theory of
evolution, including the theory of common descent, has been
proven for over a century.
I'm not sure why you think that the goalposts have been
moved. This understanding of evolution has been present
since at least the 1930s and 1940s, when Mendelian genetics
was fused into evolution during the period of the "Modern Synthesis."
If you had the idea that evolution meant something else,
okay, but that doesn't mean anyone moved any goalposts.
I'm also not sure who you think should decide whether
the theory of evolution is scientifically accurate. If not
biologists, then who? Architects? Taxi drivers? Your local
greengrocer? Who knows more about genetics, a plumber or a
geneticist?
And it's not simply a "majority vote" of biologists. It
is peer-reviewed papers containing observations and
experimental data. It is the process of cross-checking and
rechecking results. It is skepticism applied to new
hypotheses. It is an arduous process of investigation. It
is not just a group of biologists sitting around
saying, "Yep, sounds good to me."
As for what Christians believe, I'm sure the large
number of biologists who are devout and practising
Christians would be insulted by the implication that they
must abandon their faith to accept evolution as the
explanation for the diversity of life on Earth. This would
seem to imply that they must be stupid, gullible, or
hypocrites; I'm not sure which is worse.
Mutations in and of themselves are not destructive,
beneficial, or neutral. The effect of mutations depends on
the remainder of the genome and the environment that the
creature bearing that genome is in. A mutation which is
harmful in one context may be beneficial in another.
Finally, with regards to qualifications: As I have
stated before and as is plain from my postings to talk.origins, I am (currently,
though not for much longer) a law student at the University
of Chicago. I did at one time, however, study space physics
and mathematics at Rice University. I have been posting to
talk.origins for several years now, and was asked to help
with feedback to this Archive by its maintainer, Brett
Vickers. As far as I know, I have just as much (if not
more) scientific background as law professor Phillip Johnson
does, yet he is considered "qualified" by many creationists
to speak about evolution. I only ask for equal
consideration.
Most of the FAQs on the Archive were authored by regular
contributors to talk.origins. Almost all of them are either
graduate students or professors in the field that their FAQ
covers. If you are interested in the qualifications of a
particular author or feedback respondent, please contact
that person using the email address attached to their name
on the FAQ or feedback page.