It's alive! The significance of artificial life

It's here at last: synthetic life. Or, at least, self-replicating life based on a synthetic DNA sequence that mimics one from nature.

Writing in Science, Craig Venter and his team at the J. Craig Venter Institute have announced their design, synthesis and assembly of the genome of Mycoplasma mycoides, a relatively simple organism known for causing lung disease in ruminants, such as cows.

Venter's team have been working on the project for several years, first working to understand the inner workings of Mycoplasma and determining the minimal number of genes required for it to function properly as a part of the Minimal Genome Project.

They were left with only 382 of the 482 original genes in the bacterium making up around 580,000 base pairs.

The new synthetic genome is twice as large, at 1.08 Mbp, including a few designed 'watermarks' and polymorphisms, and was transplanted it into an existing Mycoplasma capricolum cell, after first removing the host cell's own DNA.

The new cells with the synthetic genome had all the expected phenotypic traits of Mycoplasma mycoides, and the cells were able to self-replicate.

Venter hopes that such 'artificial life' might one day be used to create bacteria that can produce biofuels or to develop new drugs.

However, not unexpectedly, the prospect of made-to-order organisms that can be designed in a computer and synthesised, has significant ethical and biosecurity implications.

"This is a remarkable advance as it now provides a ‘proof of concept’ that we can chemically synthesise and assemble full genomes and transplant them into recipient cells, which after selection contain only the synthetic genome, and after rounds of cell division become a new and one might argue synthetic cell," said Professor Paul Freemont, Co-Director of the EPSRC Centre for Synthetic Biology at Imperial College London.

"The applications of this enabling technology are enormous and one might argue this is a key step in the industrialisation of synthetic biology leading to a new era of biotechnology."

Others question whether the synthesis of a genome that appears in nature truly deserves the moniker 'artificial life.'

"The work reported by Venter and his colleagues is an important advance in our ability to re-engineer organisms; it does not represent the making of new life from scratch," said Jim Collins, Professor of biomedical engineering at Boston University, writing in Nature.

"It turns out that it is very hard to design even a two-gene network that performs in the way that you would like. Biology is messy and complicated, and often gets in the way of clever engineering."

Some, such as Martin Fussenegger, Professor of biotechnology and bioengineering at ETH Zurich, Basel, writing in Nature, question whether designing organisms from scratch will be possible.

"Venter’s technical tour de force extends advanced genetic engineering to organisms that thus far have been inaccessible to modification. He calls this 'going from reading our genetic code to the ability to write it'.

"It may sound scary, but there is no guarantee that what will be written will make sense. It may end up as a fairy tale, a drama, a science-fiction novel or a documentary on new therapies."

According to Arthur Caplan, Professor of bioethics at the University of Pennsylvania, one implication of the synthetic genome is that it puts the final nail in the coffin of a philosophical notion called 'vitalism.'

This is the idea that life isn't just a mechanical process, but there's an additional vital force, something Henri-Louis Bergson called "elan vital."

"Venter and his colleagues have shown that the material world can be manipulated to produce what we recognise as life. In doing so they bring to an end a debate about the nature of life that has lasted thousands of years," he said in Nature.

"Their achievement undermines a fundamental belief about the nature of life that is likely to prove as momentous to our view of ourselves and our place in the Universe as the discoveries of Galileo, Copernicus, Darwin and Einstein."

Venter's paper also opens up the possibility of the creation of life that is not directly shaped by natural selection, possibly resulting in organisms that would otherwise be impossible in the natural world.

"Tomorrow’s synthetic cell could be radically unlike anything encountered in the history of life," said Mark Bedau, Professor of philosophy and humanities, Reed College, Oregon.

There are also those who have taken the opportunity of the synthesis of an artificial genome to delve into gormless hyperbole.

“Venter is creaking open the most profound door in humanity’s history, potentially peeking into its destiny," gushed Professor Julian Savulescu, Uehiro Chair in Practical Ethics and Uehiro Centre Director, University of Oxford.

"He is not merely copying life artificially as Wilmut did or modifying it radically by genetic engineering. He is going towards the role of a god: creating artificial life that could never have existed naturally.

"We need new standards of safety evaluation for this kind of radical research and protections from military or terrorist misuse and abuse. These could be used in the future to make the most powerful bioweapons imaginable. The challenge is to eat the fruit without the worm.”

There is no question that this a landmark paper in biology - synthetic and natural. The implications may yet be years or decades away, but they are more likely to be profound than banal.