https://youtu.be/PDkvrWt7qN8

Only 4% of our genes make up who we are. The other 96% were considered 'junk DNA', until we found out that 8% of that 'junk DNA' is there as a result of gene transfer via virus, retroviruses, between our DNA and the DNA of other species.

What are viruses? Are they alive?
Viruses are not life forms, but precede life.
But they can replicate molecules w/o metabolic processes.
They are parasites.
They have always been a fundamental part of life.

Mimoviruses, found in nuclear cooling towers, mimic bacteria.

If you don't have 26 minutes to watch the Whole History of the Earth on YouTube, skip to the 21st Century, Part 3 about 12 minutes in, about viruses and what we know about them thanks to mapping the human genome and comparing their DNA.

How viruses came to be.

There are 3 theories,
Either they are regressive, they came from life and shed junk DNA to become the most simple form of RNA. or

they are progressive, like retroviruses that Transfer genes between species.

Both could be right.

Or they did not regress or progress,
They preceded life.
Viruses are singularly well adapted for the earliest form of genetic information, they are a replicating molecule without metabolism.
viruses existed before life
then they evolved with life.
viruses are a fundamental part of life on Earth.

Written and researched by Leila Battison, University of Oxford, Earth Sciences Grad Student.

Whether viruses are alive depends on the definition one employs. It's not a black-and-white issue.

It is certainly incorrect to say that viruses "preceded life." They could not exist before life since they need other life forms in order to reproduce.

Lot's Wife Wrote:
-------------------------------------------------------
> Whether viruses are alive depends on the
> definition one employs. It's not a
> black-and-white issue.
>
> It is certainly incorrect to say that viruses
> "preceded life." They could not exist before life
> since they need other life forms in order to
> reproduce.

Nobody knows. It's just a theory, but a pretty good one.

I agree with you, and will add the following:

Most biological definitions of "life" involve as a minimum some kind of "autopoietic" (self sustaining, reproducing) biochemical system; if not an outright reproducing metabolic "organism." In order for a virus to qualify as life in this sense--since it is not strictly an organism, it must have self-sustaining biochemical properties. Notwithstanding its complex biochemical components, a virus lacks such a property; and therefore is not a "living" system.

https://www.merriam-webster.com/dictionary/autopoiesis

"Some things that reproduce, such as viruses, are not autopoietic, because they are too simple to maintain themselves biochemically."

Second, if by definition viruses cannot precede life, then any theory that suggests that they do precede life is false by definition. (logical deduction!)

You’d have to watch the video but it talks about Mimoviruses, found in nuclear cooling towers, which mimic bacteria and therefore could have mimicked early cellular life.
https://www.newscientist.com/article/dn3559-massive-virus-discovered-in-water-tower/