Why would animals lose survival abilities through evolution?
It seems like humans would've had to evolve from an ancestor that had good survival skills before the brain developed. Other animals that exist now (and in the past) have great survival skills, like speed, claws, horns, strength, etc. If you put a human without intelligence in proximity to a predator, how would the human possibly protect himself? We aren't that fast or strong compared to lions, tigers or bears (sorry, couldn't resist!), and we don't have much in the way of defense capabilities, like shells or claws. So if our ancestors used to have better defense mechanisms (and wouldn't they have had to have them to survive and breed to make us?), why would we lose them? Yes, our brains are great, but isn't evolution all about improvement and survivability? If we had those defenses along with the brain power, we would be that much better off.
Also, I just want to mention that I am a Christian and I do believe in God-directed evolution. I just don't believe that everything evolved from random mutations. Honestly, even with the accepted time frame for mammals, it doesn't seem like there would be enough time for random evolution to account for everything.