The influence of area on the number of species

[Chiabete]

Yello everyone,

So my biology book states (free translation) : " The surface area of an area influences the biodiversity. The number of species doubles when the area grows ten times. Or the other way; when the area reduces to 10% the number of species drop to half."

That's cool and all..but I can't wrap my mind around it. If the area is only 10% of what is used to be, how can the amount of species be even half? I can't see the mathematical pattern here:0 I hope someone can explain this in a way that a noob like me can understand.

[JackBean]

Because it's the same like when you grow area 10-times (10% -> 100%) and get double number of species.