Wait, before everyone starts considering the inevitable future of bad genetic diversity, are we starting on an island with NOTHING?
Here's the hypothetical situation.
Everyone on earth is killed except for the people who have registered accounts on the forums.
You get 10 minutes and then you're teleported to a subtropical island populated by the other people of the community with the objects on your person (what you are wearing and holding).
Other GMOD communities are alive and on different places of the archipelago. So, naturally, the populace depends on the continents.
The Earth's atmosphere is no longer fucked up, and all the resources on the Earth have been restored to record levels. Long-extinct plants and animals live once more, although the island would have a limited large predator population.
Garry is dead, and we don't have means of communicating with other islands. The communities with <20 people are randomly distributed amongst the bigger communities.