Assembling Life From Scratch
In the search for a deeper understanding of the nature of life, some
scientists have recently focused their research on developing self-replicating
cells assembled from nonliving organic and inorganic matter.
In his laboratory, Steen
Rasmussen, team leader of the Self-Organizing Systems section at Los
Alamos National Laboratory, combines organic and inorganic materials in
an attempt to develop such protocells. These basic units show very little
resemblance to modern life. For example, the current protocell design
does not have a single biomolecule in common with a modern living cell
and exists on the nano-scale, about a million times smaller than a bacterium.
It is hypothesized that after these protocells form, they have the potential
to replicate like other forms of life, Rasmussen said during a recent
lecture at AAAS. If this path can be scientifically viewed and verified,
it may shed light on physical and chemical processes that led to the origins
of life both on Earth and throughout the Universe as well as enable new
The minimal Los Alamos protocell design consists
of three different molecules: lipid container molecules (fatty acids)
that self-assemble to form a container, genes (modified peptide
nucleic acid (PNA)) that attach to the container surface, and metabolic
molecules (pinacol) that are attached to the backbone of the gene.
None of these molecules exist in modern cells. Theoretically, the
protocell container will split into two containers (as in the picture)
when the metabolism has produced too many lipid molecules.
“The kind of questions this work seeks to address include: What
is minimal life?” Rasmussen said at the lecture sponsored by the
AAAS’s Dialogue on Science,
Religion and Ethics (DoSER) as part of its autumn series on evolution
and the origin of life. “How can minimal life be useful, are we
alone in the universe, and where do we come from?”
“While there is a rich body of research findings that support contemporary
understanding of the evolution of life,” noted Jim Miller, DoSER
senior program associate, “two of the great mysteries of science
are the questions what constitutes life and how does life originate.”
Possibly the most intriguing aspect of Rasmussen’s research is the
shattering of discrete distinctions between nonliving and living matter.
Rasmussen was quick to point out that although this research has the
potential to shed light on the origins of life on Earth, at this stage
it is more general inquiry into the undefined and poorly understood topic
of artificial life. “It’s too early to say where this research
will bring us. We need wheels on a bus before it can drive us anywhere.
We are in the process of making the wheels,” he said.
If his designs are successful, his work will have great implications
for technology and industry. Specifically, it will be possible to engineer
living-technologies, which will be robust, autonomous, adaptive, and even
self-replicating, if necessary.
Rasmussen notes that most people assume a sharp division between technology
and living systems. “Imagine the watch… if it breaks, someone
has to fix it; but if you scratch your arm, it heals,” he explained.
But “if we can understand how to make self-replicating materials…
we will then be able to make powerful technology based on the same principles
as living systems.”
With the appearance of this enabling technology, a number of societal,
ethical and religious issues emerge. Peter
Madsen, executive director for the Center for the Advancement
of Applied Ethics and Political Philosophy at Carnegie Mellon University,
pointed out that the implications of scientific research must be examined
to ensure that they are principled and ethical. But he also noted that
there are a variety of ethical frameworks that can be used.
He identified utilitarian ethics as the dominant one in contemporary
culture. He defined an act as ethical in a utilitarian sense if “it
achieved the greatest good, for the greatest number.”
In addition, Madsen, who served as the lecture’s respondent, pointed
out that the development of a new area of science and technology —
nanotechnology, for example — should proceed with prudence. Specifically,
Madsen highlighted the fact that when dealing with the scientific frontier,
previous guidelines and protocols, in addition to literature addressing
cautionary issues, may be scarce. This leads some to suggest that the
guiding ethical perspective should be the “precautionary principle”
— that is, where little is understood about the outcome of research
applications but some possible outcomes could be extremely bad, great
caution should guide the research and development.
Although Rasmussen’s research falls into the category that Madsen
classifies as frontier research, the ethicist made clear that the application
of the precautionary principle should not cause nanoscience and technological
development to cease.
Rasmussen suggested that it is in the best interest of society to engage
the various social stakeholders early in consideration of the broader
societal implications of such new and possibly profound scientific and
technological innovation. This ensures a more transparent process of information-sharing
and can reduce the likelihood of unintended consequences either through
error or malicious intent.
AAAS established DoSER in 1995 to facilitate communication between scientific
and religious communities. DoSER builds on AAAS’s long-standing
commitment to relate scientific knowledge and technological development
to the purposes and concerns of a society at large. The objectives of
the program are to contribute to the level of scientific understanding
in religious communities and to promote multidisciplinary education and
scholarship of the ethical and religious implications of advancements
in science and technology.
8 Decmber 2005