Shellfish Gene: One piece of mobile DNA has spread itself throughout the oceans
theatlantic.com
theatlantic.com
https://www.ncbi.nlm.nih.gov/nuccore/KF319019
We've got a bunch of similar viral-like DNA within our own genomes. And it appears some of those sequences might actually 'fight' each other over evolutionary time scales (dominant negative variants expressed from common viral-promoters) - to the point where their infighting actually is in some sense part of our own immune system's ability to ward off incoming viral sequences in favor of existing sequences we're playing host to.
Lots more biology for us to learn!
There's a lot to learn, but we also know a lot. To me it seems more like a nice middle ground right now - enough to get a truly solid toehold, but also much more to go :)