If beneficial mutations are a basis of evolution, what proportion of
them are beneficial? There is overwhelming agreement on this point
among evolutionists. For example,

Carl Sagan declares: "Most of them are harmful or lethal."

Peo Koller states: "The greatest proportion of mutations are
deleterious to the individual who carries the mutated gene. It was
found in experiments that, for every successful or useful mutation,
there are many thousands which are harmful."

If beneficial mutations are a basis of evolution, what proportion of
them are beneficial? There is overwhelming agreement on this point
among evolutionists. For example,

Carl Sagan declares: "Most of them are harmful or lethal."

Peo Koller states: "The greatest proportion of mutations are
deleterious to the individual who carries the mutated gene. It was
found in experiments that, for every successful or useful mutation,
there are many thousands which are harmful."

Excluding any "neutral" mutations, then, harmful ones outnumber those
that are supposedly beneficial by thousands to one. "Such results are
to be expected of accidental changes occurring in any complicated
organization," states the Encyclopędia Britannica. That is why
mutations are said to be responsible for hundreds of diseases that are
genetically determined.

Because of the harmful nature of mutations, the Encyclopedia
Americana acknowledged: "The fact that most mutations are damaging to
the organism seems hard to reconcile with the view that mutation is
the source of raw materials for evolution. Indeed, mutants illustrated
in biology textbooks are a collection of freaks and monstrosities and
mutation seems to be a destructive rather than a constructive
process." When mutated insects were placed in competition with normal
ones, the result was always the same.

As G. Ledyard Stebbins observed: "After a greater or lesser number of
generations the mutants are eliminated." They could not compete
because they were not improved but were degenerate and at a
disadvantage.