“Evolutionary biologists have noticed an interesting pattern among organisms that immigrate from a large land mass to an island. Many evolve into miniaturized forms — a phenomenon known as island dwarfism or insular dwarfism”…
https://evolution.berkeley.edu/evo-news/evolutionary-history-in-a-tiny-package/
https://evolution.berkeley.edu/evo-news/evolutionary-history-in-a-tiny-package/