Page 151 - The Errors the American National Academy of Sciences

The NAS's Error in Portraying Molecular Biology as
Evidence of Evolution

difficulties for the theory of evolution and re-
veal its inconsistencies. Before examining the
contradictions and errors of the NAS and the the-
ory of evolution in this area, let us provide some in-
formation about molecular comparisons.

The protein molecules on which
the structures and functions of living
things depend consist of amino acids.
There are 20 kinds of amino acids in pro-
teins. One particular sequence of amino
acids might give rise to a fat-digesting pro-
tein in the stomach, while another chain of
amino acids might cause an oxygen-bind-
ing protein molecule to form. Generally

speaking, the amino-acid sequence is the same for the
same kind of protein in the same species. However, the
amino-acid sequence can change between species. This is
the case, for instance, with the hemoglobin molecule, which
allows oxygen to be carried in the blood. The practice of com-
paring the differences in a particular protein molecule be-
tween species in order to draw conclusions about

evolutionary relationships is known as "molecular homology."
For instance, the amino-acid sequences of the hemoglobin
molecules in human beings, mice, and horses can be identi-
fied and compared. According to evolutionists, the protein sequences
of species assumed to have a closer evolutionary relationship should
be closer to one another. For instance, the sequences in the hemoglo-
bins of human beings and horses should be closer to each other than
to those of rats. Yet, research in this field has revealed a conflict be-
tween comparisons at the molecular level and the claims of the theory

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