Page 119 - The Errors the American National Academy of Sciences

The NAS's Errors in Portraying Common
Structures as Evidence of Evolution

color of a rat's fur also determines its dimensions. The gene which de-
termines the color of the fruit fly Drosophila's eyes also controls the fe-
male's sex organ. Nearly all the genes in higher organisms have more
than one function. The evolutionist biologist Ernst Mayr admits that
there are very few or even no genes controlling only one feature. 11

Denton cites examples of a pleiotropic gene (having more than
one effect) from chickens. The effects of a rather harmful mutation in
a single gene may include irregular wing development, lack of toes,
sparse feathers, and lung and air-sac deficiencies. The importance of
this is that while some affected features such as wings and feathers
are specific to birds, others, such as the lung, apply to many other ver-
tebrates, including human beings. Denton stresses "that nonhomolo-
gous genes are involved to some extent in the specifications of
homologous structures." 12

The exact opposite of this—that is, the emergence of non-homol-
ogous structures from identical genes—is also frequently encoun-
tered. For instance, the gene known as Distal-less is related to the
development of limbs in mice, moths, spiny worms, velvet worms,
and sea urchins, and yet the appendages of these creatures are all

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