Eliminate human-tropic viruses: We have to monitor for outbreaks when new viruses mutate and jump species to successfully infect humans. If there's zero mass immunity across the population at every outbreak, we're still in a high-risk situation.
This is also why there is a big focus now to seek out underrepresented populations in genetic analysis, because there may be population specific biomarkers that are relevant in disease that you miss if you limit yourself to the handful of widely sequenced homogeneous populations (e.g. there are Utah and Iceland datasets that are popular to use for this).
* An increase in autoimmune diseases (related to the hygiene hypothesis).
* Decreased resistance to future viral pandemics, since the body wouldn't have practice since childhood in fighting viral disease.
It could be chaotic, I think.
https://m.youtube.com/watch?v=SbvAaDN1bpE
Are we also eliminating transposons? We would not survive that.
Strong statistical signals but no sharp lines between groups - we as a species like travel and sex.
For example the Basque population has clear genetic differences to the rest of the Iberian and Westerner population [1] but that doesn't make them a different race.
Race is just a social construct, mostly based on visual traits.
[1] https://www.ibe.upf-csic.es/news/-/asset_publisher/PXTgqZXxl...
And there's not even the only one (there are other syncitins).
Disclaimer: I'm not a medical professional
There is more genetic variation within a what we might call a race than between them. And it's interesting to note that the genetic diversity of Eurasian populations is in large part contained within the much greater diversity of Africa. In some sense we're all Africans. On top of that there has been a good amount of mixing, both historically and in the present day.
To think in terms of "races" might lead one to hold a mental model of impermeable boundaries between populations that in many cases were never present, and certainly aren't today. Geneticists tend to use the word "population" instead, since it doesn't connote any unhelpful assumptions about uniform or fixed phenotypes within a well-defined species subgroup.
Of course there are certain obvious environmental adaptations that have been selected for in different geographies/climates, as well random genetic drift between distant populations. Sometimes those difference might have medical relevance, and you can make statistical generalisations about the prevalence and distribution of genetic markers within any group you like. But for most medical and public policy applications it is likely most useful to focus on populations within an administrative area, and increasingly, individualised medicine.
If you map out the reproductive connections betweeen these various small groups, they all connect quickly in terms of evolution.