To call the natural process of mutation, literally one of the requirements for any genetic evolutionary progress, "deteriorating" is, at best, short sighted. Most mutations do nothing, most of the ones that do something don't occur in the one sperm that makes it into the ovum, and most of those that do something and make it into the ovum cause an early termination before birth. Some of those that get through all of these hurdles are the ones that cause random genetic variation and increased diversity, without which we actually DO get things like Hemophilia or other sex-linked issues going rampant in any given gene pool. Evolution takes a LONG time to work, but it requires wet and moldable clay to sculpt.