It could be the lack of genetic culling, but would you imagine that in a single generation that would lead to an epidemic of epic proportions? If not due to lack of culling, then wouldn't you suspect that the same environmental force that is saving babies from death is dooming them to disability?
Julia Hanna and I are doing livestreams every Friday night at around 8:00pm Central Standard Time on both our channels. For notifications, please make sure that you are subscribed to my channel. Click on the link below, and if you are not yet subscribed, it will give you a chance to do so.