Any ideas how to raise babies more efficent?
Evolution does not optimize for the individual, but the species.
As the RQ shows, this process often leads to a dead end. Such as a short term success for cancer, but no long term success. Deadly infections lose their deadliness over time, as killing the host does not lead to propagation.
Evolution often falls into a local optima, which will inevitably lead to extinction.
Covid seems to have its mortality dramatically shrunk.
Our genomes are full of bits and pieces of ancient disease DNA. Our bodies are full of bugs that have evolved into peaceful coexistence. Some bugs even became part of us (mitochondria).
That does not support your argument that there is a adaptive advantage for reduced deadliness. The fact that it was exceedingly deadly to non co-evolved hosts indicates it was not the disease that became less deadly, but that the co-evolved hosts developed better defenses.
> Our bodies are full of bugs that have evolved into peaceful coexistence.
That is a argument that there is a continuous adaptive advantage to reduced deadliness down to ~0%. Again, Rabies had and continues to have a nearly 100% fatality rate in co-evolved hosts for thousands of years. Smallpox had a 10-30% fatality rate. Any magical inherent adaptive advantage for reduced deadliness failed to materialize to continue pushing down their deadliness.
Or put another way, a disease can have a 30% mortality rate and still do a really bang-up job at propagation with limited adaptive pressure to reduce that further for thousands of years. Peaceful coexistence is more likely a artifact of the specific dynamic than any sort of meaningful fundamental advantage to reduced deadliness.
