[mig39]

I think the rule of thumb is that small animals tend to get larger when isolated, and larger animals tend to get smaller.

[shusaku]

… that’s literally written in the first paragraph of the original linked article.

[mkl]

Yes. Island gigantism and insular dwarfism (https://en.wikipedia.org/wiki/Insular_dwarfism).

[fireflies_]

It's a shame that these aren't parallel. Why couldn't it be "insular gigantism" or "island dwarfism"? (But not both!)

[messe]

What’s even worse is that Island Gigantism is a Germanic derived word followed by a Latin derived word, while Insular Dwarfism has the etymologies the other way around.