Life is a peculiar thing
What is life – where does it begin and where does it end? It is not easy to define life even if you are a researcher in the biosciences and medicine.

Professor Hannu Sariola is a doctor, pathologist, and researcher in developmental biology. You would be forgiven for assuming he is a man with a clear understanding of both life and death. However, when asked “what is life”, he answers: I don’t know.

– We only know life as it exists on our planet, and maybe we could define it like this: All living things consume energy, Sariola says.

According to Sariola, the great division of biological life runs between plant and animal: these two kingdoms diverged long ago, even though they still share certain basic characteristics. Fungi are placed between the two kingdoms, although Sariola would locate them closer to animals than plants, based on their biology. 

In the microbiological realm, Sariola draws the line of biological life at viruses. – Viruses do not have independent life.

Whether viruses are alive is a controversial topic in the scientific community, says Sarah Butcher, professor of microbiology.

– From the perspective of biology, life involves certain processes, such as respiration and energy metabolism. In this sense, viruses are not alive, she states.

If a virus which exists as a parasite of a cell were considered alive, would that not mean that a computer virus would also be alive? It can also be transmitted to other computers, replicate itself and spread, Sariola ponders.


Interesting things are happening on the borderlines of biological life and machines. With strides in robotics, artificial intelligence, and biological materials, the border is becoming increasingly nebulous.  

According to Butcher, the current classifications of life may well change in the future. For example, synthetic biology, which combines biology with technology, is only getting started. Researchers are now able to build completely new molecules which can reproduce either independently or through parasitism. – In the future, we may be able to create entire living organisms for research or biotechnology, she says.

Academician of Science, professor Ilkka Hanski, who studies ecology and evolutionary biology, calls the current life-forms on Earth “old life”, and self-replicating artificial intelligence “new life”.

– Personally, I consider the development of artificial intelligence and robotics a threat to old life, Hanski says, but points out that he is not an expert in this field.

If a sophisticated artificial intelligence were combined with state-of-the art synthetic biology, the result could be a completely new type of life somewhere between old life and robotic life.

According to Hanski, some synthetic biology researchers think that the disappearance of “old life” is not a problem, as new life can always be created. – This is an incredibly naïve idea which reveals lack of understanding about ecological interactions and the complexity of their evolution. Some think that we can just build new ecosystems! They do not understand that an interactive relationship involving just three different organisms generates highly complex dynamics.

The question of what should be studied to ensure life on our planet is a serious one for the professor.

– To maintain life on Earth, we should find solutions to huge issues. Personally, I consider global capitalism based on constant growth to be one of the most difficult challenges. It is the foundation upon which everything else rests. No feasible alternative to a global market economy currently exists, but we should try to find one quickly, Hanski muses. – We must find a path to a stable economy which would not rely on continuous growth. A stable economy is a necessity for seriously embarking on the work to find the solutions to environmental problems.

Read more: Life in a nutshell