A zombie apocalypse wipes out almost the entire human specie…

A zombie apocalypse wipes out almost the entire human species before the zombie threat is eliminated. Only a group of 100 people who were at a family reunion on an uninhabited island survived. They returned to the mainland completely unaware of what had happened to everyone. Answer the following question(s) regarding the few survivors who now begin to rebuild the human population.Despite an abundance of habitat, why will it be difficult for the human species to recover?