As seen in the picture, John white is very excited about the gold they will find. While the crew was shocked to see there was a new world, which if you can imagine was probably was very scary. Also they brought lots of people with so they have a town.
Someone is staying to help supply the the crew when they get back from trying to find food. Even though there is only one man here doesn't mean he isn't capable of doing things on his own. So they kept rotating positions to see who stays back and who goes hunting, to bring back to the camp.
As the crew followed the Indians to croatoan island they were talking until night fell. When the Indian snuck up behind them in the night dagger in hand. They killed the Americans, so when john white comes back he will know they are not wanted there. So the Indians had to be clever about where to put the bodies. They must have purposely left one body to make sure they got the message to never come back yet, so they threw the bodies in the ocean where no one can find them that why they left the marking in the tree with the objects on the island so they didnt sleep with it on..