In 500 years later, I believe that birds will be obese in a very alarming way. There will be too much garbage and animals will confused it for food and eat it. Toxins in their body will make their intestines ill and cause obesity. THey will loose their ability to fly. Little by little generations will continue to live with birds walking rather than flying all over, and they will adapt to the environment in that way. I think that we aren’t being conscious of how animals will evolve in a bad way because we are living in a contaminated world, and I don’t believe it will get better as years pass.