Synthetic biology is an emerging field of study that applies engineering principles to biology to solve a wide range of real-world problems – from extinctions to malaria to invasive species.

From bioluminescent algae to self-fertilizing banana slugs and carnivorous plants that can count, the natural world shows a phenomenal diversity of functions and abilities.

Now, science is uncovering more about how these features are expressed at the genetic level – and giving us a new set of tools to play with.

The possibilities within the field are vast and ever-expanding, but its risks are similarly huge, and regulators are lagging behind the new developments at hand.

That’s why this year, at its recent World Congress, the International Union for the Conservation of Nature (IUCN) adopted the first global policy on synthetic biology and nature conservation.

In this explainer, we take you through exactly what synthetic biology is, how it works, how it differs from genetic engineering, what it can be used for and some of the risks and concerns around it – from practical impacts to some of the biggest philosophical questions about the nature of life itself.

What is synthetic biology?

Synthetic biology is an area of science that combines biology, chemistry, engineering and computer science to design and build new biological organisms and systems – or to give existing ones new abilities.

Essentially, it makes use of the principles of engineering to ‘program’ living things to solve problems in predictable, robust and efficient ways.

How does synthetic biology work?

The key technology in synthetic biology is DNA synthesis.

That means figuring out which sequence of adenine (A), guanine (G), cytosine (C), and thymine (T) – the four chemical ‘building blocks’ of DNA – gives the function that you’re interested in, synthesizing that in a lab, and then putting it in a biological host.

“Just as computers speak in the language of ones and zeros and can be programmed, life speaks in the letters of A, T, C and G – and it can similarly be programmed, just as we program code on computers,” said futurist academic Amy Webb in a World Economic Forum video on the topic.

How does synthetic biology differ from genetic engineering?

Synthetic biology is often described as ‘genetic engineering 2.0’. While the two fields overlap, there are some important differences in their respective scopes, approaches and ambitions.

Genetic engineering modifies existing organisms by inserting, deleting or altering specific genes – for example, making a plant resistant to pests by inserting a bacterial gene.

Synthetic biology, meanwhile, designs and constructs entirely new genetic systems or organisms – such as creating new bacteria that can remove pollution from water and then break down without a trace.

Essentially, you could say that genetic engineering edits nature’s existing code, while synthetic biology writes new code.

What can synthetic biology be used for?

The potential applications of synthetic biology are vast and broad: from healthcare to climate adaptation to agriculture, industry and beyond.

For instance, the mRNA vaccines used globally against COVID-19 are a form of synthetic biology, as are the plant-based meats used in the iconic vegan ‘beef’ Impossible Burger, which are made from engineered yeast.

Within the field of conservation, the topic of whether or not to make use of synthetic biology “has long attracted debate,” noted the IUCN in a press release, “with a small proportion of the conservation community supportive, a small proportion opposed, and most conservationists until now unsure or undecided on the subject.”

The organization highlighted that synthetic biology cannot and should not replace existing efforts to combat the climate and biodiversity crises – though it could complement them.

For instance, the science could be used to build genetic diversity within endangered populations, making them more resilient to disease and adaptable to different food sources and the changing climate.

Scientists in Australia, for instance, are currently considering how to bioengineer coral to be more resilient to rising sea temperatures.

Synthetic biology could also be used to help eradicate invasive species – a major threat to native biodiversity across the planet – by doing things like making all of such species’ offspring a single sex, or making them only produce infertile males.

As such, the field “gives new hope for saving the many threatened species which face as-yet-unmanageable threats,” said Maria Julia Oliva, a member of the IUCN World Commission on Environmental Law and director for policy and sector transformation at the Union of Ethical BioTrade.

Beyond the conservation sector, synthetic biology is already being used to explore how to recreate the plethora of things we currently craft out of polluting petrochemicals.

For instance, scientists are creating microorganisms that can produce biofuels from sustainable feedstocks like plant biomass and even plastic waste.

Others are exploring how to change the properties of natural fibers like cotton and hemp – such as by making them waterproof, quick-drying or UV-proof – so they can be used in place of petroleum-derived synthetic fibers like polyester and nylon.

Also within the fashion industry, scientists are already ‘programming’ microbes to produce fabric dyes using a fraction of the water and none of the pollutants or petrochemicals used in conventional large-scale manufacturing.

What are some risks and concerns around synthetic biology?

Alongside all of these inspiring possibilities, the field of synthetic biology carries significant ecological, security, health and ethical risks.

Unintended consequences are a hallmark of so many of humanity’s attempts to solve problems in nature.

Think the introduction of invasive cane toads to control pests devouring sugarcane plantations in Fiji, or the EU’s policies to promote biofuels, which instead incentivized the felling of old-growth tropical forests for palm oil plantations.

Because the impacts of unleashing a synthetic biological system or organism are far-reaching, it’s also critical to consider who gets to decide about doing so – and who reaps the benefits.

“Synthetic biology applications have implications for all sectors of society – in particular for Indigenous Peoples and local communities,” noted the IUCN press release.

“The policy spells out in clear terms considerations for ensuring input into planning and decision making, including through the principle of free, prior and informed consent.”

The significance of such decisions is culturally mediated, too.

For Aotearoa New Zealand’s Māori, for instance, synthetic biology presents a particular challenge to whakapapa, the genealogical connections through which they frame the universe and understand their relationships within it.

That doesn’t mean that all Māori are opposed to synthetic biology, but it does necessitate particular kinds of precautionary frameworks that safeguard Indigenous interests and values.

Futurist Webb raised a similar concern to that of many Māori.

“We live now in a world in which a new type of life exists, whose parents were not living organisms – the parents were computers, and the scientists entering code into those computers,” she said. “It does beg the question: what is life?”

How we choose to answer this question will have major implications for our values, laws, institutions and economy, she added.

In this context, the new IUCN policy’s “balanced posture” that “allows innovation but insists on scrutiny” seems key – and similar policies and frameworks are now needed across sectors and at local, national and international levels,

“This technology is already here,” said Webb. “It’s not somewhere off in the distant future – it’s now, and there’s not a single industry that [it] will not at some point touch.”