Science Memes @mander.xyz fossilesque @mander.xyz 2w ago Foster's Rule https://en.m.wikipedia.org/wiki/Foster's_rule
Ok I think if you replace in with on maybe it is easier to understand
That's a regional thing. Some places say on an island, others in an island.
Ok I am not a native speaker of English but I never heard in an island until I saw your meme.