Speaking strictly in the context of evolutionary biology, humans appear to be devolving. From hereditary heart defects to cystic fibrosis, the human genome is being shot through with mutation after mutation, almost all of which are degenerative. In nature, individuals with these mutations would eventually be weeded out by the process of natural selection, but with our advanced modern healthcare, nature loses at least some of her selective power.
Natural selection is a brutally efficient process. It acts to keep good genes in a population and bad genes out. For example, if a crippled wildebeest is born, it will invariably die within a matter of days, thereby keeping those genes out of the population gene pool. Conversely, if a wildebeest is born with strong, healthy legs it has a better chance of passing on its genes. Even minor physical defects or advantages cannot escape the reach of natural selection.
Humans are something of an evolutionary enigma. If a baby is born with defective legs, rather than allowing it to die we care for it all the more. That baby then has the chance to grow into an adult and live a relatively normal life. Likewise, if a congenital heart defect is discovered in an individual, we simply perform a surgery to repair it. Now it is important to remember that while we can allow the crippled individual to live a good life or successfully treat the individual with the heart defect, we cannot remove the defective genes that resulted in their errant physiologies. Through these actions, we have effectively preserved faulty genes in the human population.
It has even been shown that in countries with poor or non-existent healthcare infrastructures, individuals are genetically healthier than in wealthier nations with well-funded healthcare programs. The populations in these poorer countries have fewer mutations in their genomes as well as more genetic diversity, which in biology translates to a healthier gene pool. However, while most of the human population may have very limited access to adequate healthcare, it still has more than your average mammal.
Some would argue that while our genome may be plagued by degenerative mutations, our minds are constantly evolving to compensate. The major problem with this argument, besides being scientifically unsound, is that it mistakes intelligence for knowledge. To the best of our knowledge, we are no more intelligent than the ancient Egyptians (many would argue that we're actually dumber than they are, but that's a topic for another day). What we have is an extensive database of knowledge that we have been building since the dawn of humanity. It speaks nothing of our intelligence as a modern society. Rather, it speaks of the ingenuity of previous cultures and civilizations that has paved the way to allow us to enjoy the delicious-although sometimes bitter-fruits of the age of technology and information.
So is it a bad thing that we protect the weak and preserve their faulty genes in the human population? Absolutely not. It's part of what makes us great as a species. Empathy and reverence for all human life are the very qualities that make us, well, human.