It will be interesting to see what kind of in universe explanation they come up with for that, but for now, I love the fact that Taylor survived on his own in a dinosaur infested jungle for four months. As I said in a previous post, I have feeling that the portal operates on principles that are somewhat similar to that of a Stargate. Radio waves can travel in both directions at once, but solid matter can't. That's an interesting notion. A notion that has occured to me is that maybe they should find plants an animals that don't appear in Earth's fossil record.