And that's just the beginning: https://www.cshl.edu/the-non-human-living-inside-of-you/
Barbara McClintock discovered viral activity of our DNA in the 1940s. In 1983 she received a Nobel Prize for that discovery: a lot of our genes are from viruses.
Since 2014, we’ve known that at least TEN-TO-ONE there are MORE microbial cells in the human body than human cells: https://web.archive.org/.../faq-series/5122-humanmicrobiome. Now, keep in mind that we’ve known for almost eighty years that a portion of the DNA in those human cells is virus DNA.
The math is pretty clear. 91% or more of our cells are microbes. Of the remaining 9% or less that are human cells, half of their DNA is viral. Every tissue in the body is replaced often, with the longest outliers lasting about seven years, except for some optic, possibly cardiac and definitely cerebral cortex cells. Altogether, those ever-persisting and never-replaced cells are fewer than twenty billion. There are about ten trillion human cells in you, and one-hundred trillion microbe cells. Two-hundredths of 1% of the human cells (the ones that survive anyway) remain with you indefinitely. Inside these cells reside the viral DNA as well. And, as they die off, and as the rest of you is replaced again every seven to ten years, you are increasingly less "you" than ever. What we think of as the ongoing physical human “us” is about half of two-hundredths of 1% of 9%. And that infinitely miniscule fraction of "humanity" becomes vanishingly small through the course of our lives.
All of a sudden, several religious ideas become palpable truth. In Christian theology, our body is not actually ours. In Hebrew theology, our body is not actually ours. In certain forms of Buddhism and Hinduism, sometimes this is communicated as “the self is an illusion.” Across many ideologies, this concept that we must take care of the “temple” implies that whatever we call “us” is a mix of caretaking and the practices for which we must take care. There are no objects. And there is certainly nothing in a fixed frozen snapshot.
I like to talk about us as shifting-states or wending-paths. There is no object. We cannot objectify the human. To talk about ourselves as unchanging objects is both heretical sin and unscientific nonsense. As a physical specimen, my body is less than half of two-hundredths of 1% of 9% of what it was when I was in my twenties. And the same could've been said in my twenties about my teens, and the same in my teens about my adolescence. My skeleton may remain similar ratios; but the cells have gone. All are replaced. Most are bacteria. Half of the DNA in the rest is virus.
Every behavior, decision, activity, and even thought has a physical consequence of changed genetic expression. We flip switches in our DNA all the time. Even changes in our sleep alter our genetic expression and which mRNA we will use: https://www.pnas.org/content/110/12/E1132. We activate and deactivate microbes and viral genes all the time as well. DNA shifts. Which mRNA we use and how we use them in transcription is a moment-to-moment changing landscape. Just a drink of alcohol makes you activate tumor necrosis factor in the brain and a litany of other mRNA alterations: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6875773/.
None of it was ever frozen in time. And half of your DNA was always virus DNA. Catch up to the 1940s at least. You weren't born this way. You aren't destined to never change. Things don't have to stay the same. All of us are always changing... well, except for that less-than half of two-hundredths of 1% of 9%. But you really want a mind-bender? The minerals and substrates and atomic particles which comprise those persistent cells have also come and go, degraded, bonded, and more. Change isn't just coming. Change was here long ago.