IMO, I (the mind) do exist at nanoscale. i.e. an emergent product of microtubule networks.
You correctly address evolution via natural selection as the creative process, but we must also remember that life itself began with the self-organization of a single self-replicating polymer.
And the halfway stage was/is a virus, a self-organizing polymer that is unable to self-replicate. It is called non-living for its inability to self-replicate.
Are viruses alive?
The usual answer to this question (and usually for the purpose of passing your Biology GCSEs) is that viruses are not alive, because they do not complete all of the seven life processes: Movement, Respiration, Sensitivity, Nutrition, Excretion, Reproduction and Growth.
However, viruses have genetic information coded in DNA or RNA, a characteristic shared by every other living thing. So does that mean they can be considered ‘alive’? Let’s take a look at what biologists mean by ‘alive’.
We can agree that dogs, for example, are living creatures; they grow, reproduce, release energy from nutrients, move and respond to the world around them. They also excrete waste products (including poo). But viruses don’t show all these characteristics.
Viruses can’t move, grow, convert nutrients into energy or excrete waste products. But viruses certainly reproduce, infecting people and causing illnesses. It’s how they reproduce that’s unusual.
Viruses lack essential machinery needed to reproduce by themselves. In fact, viruses can only reproduce after infecting a living cell - a process called viral replication. Once inside a living cell, viruses re-program the cell’s machinery to produce viral proteins and genetic material to make new copies of themselves. Viruses with an envelope steal a fatty layer from the cell. Then, new virus particles infect other cells, turning them into virus production factories too.
The tobacco mosaic virus was the very first virus to be discovered.
It infects chloroplasts in the leaves of plants
Where did viruses come from?
Viruses have been around for a few billion years, but it’s not clear which evolved first: viruses or cells. Three theories try to explain where viruses came from. The first suggests that genes encoding viruses might originally have come from cells, like bacteria. Small sections of DNA may have escaped from a cell’s genome, eventually gaining a protein coat: bingo! The first virus.
The second theory suggests viruses evolved from an ancient single-cell organism that stopped being able to reproduce by itself, becoming dependent on host cells instead.
The final hypothesis proposes that viruses existed before cells; ancient viruses may have evolved over time to produce membranes and cell walls, giving rise to living cells. It’s possible that all these theories are right.
What would happen if all viruses disappeared?
Viruses have led to pandemics and death, which has caused them to have, it’s fair to say, a pretty bad reputation. But not all viruses are harmful. Millions of years of evolution alongside host cells mean that viruses are very selective about which type of cells they infect (for example, plant viruses don’t cause disease in humans), and some viruses may provide benefits to their hosts.
In fact, some scientists think that if all viruses magically disappeared one day, it would end life as we know it.
Viruses help maintain ecosystems by making sure that individual populations (such as insects) don’t outcompete other populations, causing a huge crash in biodiversity. Viruses kill around 20% of microbes in the oceans daily, releasing nutrients from dead cells which help feed other microbes. This is essential because microbes in the oceans produce about half of the oxygen on Earth. Viruses also affect carbon dioxide levels on Earth by helping to hide carbon deep in the oceans.
You’ve probably heard of ‘good bacteria’ which help keep your guts healthy. Viruses may help to regulate bacteria in your guts and train the immune system to fight some infections. Viruses can be used as tools in medicine, for example bacteriophages - viruses which infect bacteria. There should, in theory, be a bacteriophage capable of killing every single bacterium on Earth. If we can match the right bacteriophage to an antibiotic-resistant bacterium, we could treat untreatable-infections. Viruses can be used to deliver correct copies of defective genes into cells during gene therapy and research even suggests that viruses that specifically kill tumour cells might help us to fight cancer.
We’ve probably only discovered a tiny fraction of the viruses on our planet, with most research focusing on disease. But the more we learn about viruses, the more we understand their importance in the life of the planet.
So when we speak of life, we must include the entire spectrum of connecting parts.
Sputnik virophage
Mimivirus-dependent virus Sputnik (from Russian спутник “satellite”) is a subviral agent that reproduces in amoeba cells that are already infected by a …
Virology · Structure · Other viruses of Sputnik genus · (Sputnik virophage - Wikipedia)
Genome sequence analysis showed that Sputnik has genes related to viruses infecting all three domains of life. Here, we report structural studies of Sputnik, which show that it is about 740 Å in diameter , has a T=27 icosahedral capsid, and has a lipid membrane inside the protein shell.
Evolution of viruses
Key points:
Viruses undergo evolution and natural selection, just like cell-based life, and most of them evolve rapidly.
When two viruses infect a cell at the same time, they may swap genetic material to make new, “mixed” viruses with unique properties. For example, flu strains can arise this way.
RNA viruses have high mutation rates that allow especially fast evolution. An example is the evolution of drug resistance in HIV.
Evolution of viruses (article) | Khan Academy
IMO. the meaning of the term “life” includes all stages of living expression in nature.
