In many areas of the Radivan universe, there is a strong prejudice against bio-technology. There are vivid memories of the assorted disasters the technology -- or its application -- has caused. Entire planetary populations have died of plagues, intentional or not. In most places, as long as the changes aren't too visible, they're ignored. Few people even consider how far human basic has shifted since humans left Earth. Normal lifespan has more than doubled, and with good medical care, more than trippled. Nearly all genetic disease has disappeared, long-term exposure to zero-gravity doesn't cause bone loss, the ability to repair damage from radiation is dramatically increased.

In some places, bio-tech has been embraced, either out of necessity, or shear local eccentricity. There are pan-humans adapted for nearly every environment found in the Nexus, from dedicated heavy-worlders, to gilled amphibians, to winged fliers on low-gravity worlds.