The first question is whether phenotypic changes driven by artificial selection are an apt analogy for adaptation in nature.

Wallace found fault with two aspects of domestication as a heuristic
for understanding adaptation in nature. He argued first that the analogy
was flawed: artificial selection requires an intelligent selector, whereas no
such force acts in natural systems. Additionally, he insisted that the selection
itself was fundamentally different, leading to intrinsically different
kinds of variation. Domesticated species, he wrote, ‘‘are abnormal, irregular,
artificial; they are subject to varieties which never occur and never
can occur in a state of nature: their very existence depends altogether on
human care; so far are many of them removed from that just proportion
of faculties, that true balance of organization, by means of which alone an
animal left to its own resources can preserve its existence and continue its
race’’ (Darwin and Wallace, 1858).

It is tempting to conclude that observable phenotypic differences
are adaptive, particularly in domesticated organisms where selection is
strong and the direction of selection can be surmised. However, many of
the differences between domesticates and their progenitors may not be
adaptive. A number of alternative processes can explain observed
phenotype–genotype associations, including genetic drift, selection on a
correlated trait, pleiotropy, or even natural selection working in opposition
to anthropogenic selection. It therefore behooves us to endeavor to
test adaptive hypotheses rather than assume them to be true (Gould and
Lewontin, 1979).

Ross-Ibarra, J., Morrell, P. L., & Gaut, B. S. (2007). Plant domestication, a unique opportunity to identify the genetic basis of adaptation. [included in:]

Avise, J. C., & Ayala, F. J. (2007). In the light of evolution I: Adaptation and complex design. Proceedings of the National Academy of Sciences

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