Population can be used for Study. Study is a synonym of Attention. 
Mushroom is a synonym of Spread. Invasion is a type of Spread. Invasion is related to Attack. Attack is related to Jump. 
Population --UsedFor--> Study <--Synonym--> Attention 
Mushroom <--Synonym--> Spread <--IsA-- Invasion <--RelatedTo--> Attack <--RelatedTo--> Jump 