[[If anything, single celled organisms are as robust as they have ever been.]]
Well we don’t really know that- it could well be that they have ‘degraded’ from species that, like htose that live al ong time, they too lived very long times- In the old testament, man lived hundreds of years- one living 900 some odd years- we’ve degraded over time due to mutaitons (somethign the ‘Mitochondrial EVE’ Project confirms)
Feel free to post your data supporting this conjecture.
In the meantime, single celled organisms chug merrily along with undimished ability to live and adapt.