Scientists One Step Closer to Artificial Life and the Best Case for ID
Mary Shelley’s famous Gothic horror story presents a fascinating character: Victor Frankenstein. As a burgeoning scientist, Victor becomes obsessed with discovering the “principle” that distinguishes life from inanimate matter. After many long hours of study and laboratory work he uncovers “the cause of generation and life,” and becomes “capable of bestowing animation on lifeless matter.”
Frankenstein exercises his newfound ability by bringing a humanoid monster to life, only to abandon it in disgust. Victor’s moral failings lead to several tragic deaths at the hands of his creature, including those of his brother, his best friend, and, later, his wife on their wedding night. Even though the scientist and the creation are somewhat sympathetic figures, it’s not clear who’s the true monster—Victor, the creature, or both.
If there is a real life Frankenstein, he might very well be Craig Venter.
Venter stands as perhaps one of the most important scientists in the last decade or so. (In 2008, Time magazine voted him one of the world’s 100 most influential people.) As a major player in the emergence of the science of genomics, he is a scientific maverick who thinks big and has little patience for the red tape and bureaucracy that characterize many scientific programs. And like Victor, he is a polarizing figure, much admired and much hated by people within and outside the scientific community.
Recently, Venter founded a company called Synthetic Genomics. As with Shelley’s protagonist, Venter wants to create life in the laboratory. The new company is devoted to creating artificial, nonnatural life microbes that have commercial utility, particularly for the production of ethanol, hydrogen, and other forms of renewable energy. Once again, Venter has generated a mixture of excitement and horror among the scientific community, and the public at large.
Scientists like Venter who pursue the creation of artificial and synthetic life claim that these novel life-forms will benefit humanity. If they accomplish the desired breakthrough, it could go a long way toward resolving the energy and climate crises.
The very real prospect of scientists creating life in the lab raises all sorts of theological questions. Should human beings “play God”? Some conservative Christians worry that the genesis of novel life-forms by human hands eliminates the need for a Creator by substantiating the evolutionary paradigm. Many theists and atheists, alike, believe that if scientists can create life in the lab, then there is nothing special about any life. Therefore, the origin-of-life could have easily taken place on the early Earth without God’s necessary involvement.
The latest work by Venter’s team stands as another milestone in the quest to create an artificial life-form in the lab. Ironically, instead of supporting an evolutionary origin of life, this research demonstrates that life’s beginnings and transformation cannot happen apart from the work of an intelligent agent.
This week I will discuss the progress Venter and his team at Synthetic Genomics have made toward achieving their goal. In the next couple of weeks I’ll describe the details of their most recent accomplishment and will eventually explore the implications of this work for the intelligent design (creation)/evolution controversy.
The Path to Artificial Life
Venter and his coworkers became interested in creating artificial life as an outgrowth of another project. Initially, they were interested in determining the minimum genome for life. The term “genome” refers to an organism’s entire hereditary information, stored in the nucleotide sequences of DNA. The information housed in genomes exists in units called genes. These units contain the information that the cell’s machinery uses to make proteins.
Proteins take part in virtually every biochemical process and play critical roles in nearly every cell structure. Cataloging the number and types of proteins present in an organism gives biochemists important insight into its structures and operations. Venter’s team hopes that identifying the minimum genome will provide them with an understanding of life at its most fundamental level.
In their attempts to reach that target, Venter’s group has focused attention on a bacterium called Mycoplasma genitalium. This microbe has one of the smallest, if not the smallest, genome known to scientists. M. genitalium parasitizes the human genital and respiratory tracts. Its genome possesses about 480 gene products. Because its genome is so extensively pared-down, it’s ideally suited as a model system to determine the absolutely indispensable requirements for life—the “non-negotiable” biochemical systems that must be present for an entity to be recognized as a form of life.
The researchers reasoned that it is quite likely that the bare essential genome is much smaller than 480 gene products. It turns out that a significant fraction of this parasite’s genome is dedicated to mediating interactions between the parasite and its host and can be considered as nonessential to a strictly minimal life-form.
Using an experimental approach, Venter’s team worked to ascertain the minimum number of genes needed for life. Their protocols involved both the random and systematic mutation of M. genitalium genes to determine those that are indispensable for life. (Biochemists refer to these procedures as knock-out experiments.) If a gene is nonessential, M. genitalium will still grow after the gene is mutated.
Once the essential or minimum gene has been determined via the knock-out experiments, the scientists hope to confirm their result by preparing a synthetic minimal genome and introducing it into a cell to see if the cell with the transplanted genome grows. They realized that in the process of identifying the minimum genome, they came just a few short steps away from making artificial life in the lab.
Steps to Creating Artificial Life
Venter and collaborators’ approach to creating an artificial life-form is called a top-down strategy. It involves starting with a naturally occurring microbe and stripping it down to its bare genetic and biochemical essence, and then modifying it by adding nonnative genes to the minimal genome to generate a nonnatural form of life.
The major stages in this effort involve:
- systematically eliminating genes from the M. genitalium genome to identify all the essential genes;
- synthesizing the building blocks of DNA from the minimal genome from nucleotides,;
- introducing the minimal genome into the cytoplasm of a M. genitalium cell that has had its original genome deleted;
- growing and then replicating the organism harboring the synthetic genome.
Once these steps are accomplished, a nonnatural organism, called Mycoplasma laboratorium, will have been created. At this point, the researchers will have the genetic foundation in place to build an organism with any biological properties they desire. For example, they currently plan on adding genes to the minimal genome that will produce proteins that can generate hydrogen.
A Brief Progress Report
To date Venter’s team has made remarkable progress toward their goal of producing Mycoplasma laboratorium. They have identified the essential gene set (which consists of about 380 genes). They have also synthesized from scratch the entire genome of a wild-type M. genitalium and cloned it (made copies) in yeast. Additionally, they have transferred the wild-type genome of M. genitalium into a closely related Mycoplasma species.
The next step is for the researchers to put all of these steps together to synthesize, clone, and introduce a synthetic minimal genome into M. genitalium.
Though this last milestone seems rather trivial, it is technically quite challenging. Next week I’ll illustrate these technical challenges by describing their most recent efforts to improve upon the efficiency of synthesizing and cloning a synthetic genome in yeast, a vital step in “bestowing animation on lifeless matter.”
originally posted 1/22/09