Biomedical Engineering Reference
In-Depth Information
The Unity of Life
Concepts that refer to the “unity of life” and our “rootedness in nature”
may invoke a historical premise, namely, that all life-forms are descended
from a common source, or at least that human beings are related to other
life-forms through the long historical processes of evolution. Ironically,
however, the results of genomic research suggest that humans are related
to the rest of life—or rooted in nature—in unexpected ways.
First, just as the Copernican revolution led humanity to recognize that
it did not stand at the center of the universe, so the genomic revolution
shows us that we do not reside anywhere near the trunk of the tree of
life. Astronomers locate the earth somewhere in a minor galaxy in an
undistinguished spot at the periphery of celestial events. Similarly, geneti-
cists locate multicellular eukaryotic organisms, such as human beings, in
a most undistinguished spot at the periphery of evolution. For the most
part, living nature consists in prokaryotes, bacterial creatures not bur-
dened, as are eukaryotes, with nuclei in their cells. Eukaryotes, and par-
ticularly the multicellular eukaryotes of which plants and animals are
familiar examples, “form an outlying twig on a tree of life whose trunk
and branches are otherwise largely bacterial.”
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Second, once one manages to locate the outlying twig where multi-
cellular eukaryotes are found, one finds that they resemble each other.
Seen in the context of genetic variation across all life, little distinguishes
human beings, say, from yeast. Researchers can find only three hundred
human genes that have no recognizable counterpart in the mouse.
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The
striking similarities between humans and their close genetic cousins, such
as worms, and the differences between them and almost all other living
things lead one to ask whether humanity has anything to learn from these
relations besides humility.
Third, ethicists have begun to question the extent to which historical
concepts, such as the unity of life, can remain meaningful as biotech-
nology increases its power to alter genomes for instrumental purposes
and, eventually, to create genomes artificially. These artificial creatures,
after all, would have to count as living—as part of the unity of life—
even though they have a different history. The Ethics of Genomics Group,
in a thoughtful essay published in
Science
, discuss the ethical and reli-
gious issues raised by efforts to build new organisms, beginning with
