system
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human
ELI5 Why are animals (and our old relatives) so small on the island of Flores?

Been wondering for a while why so many animals and our old relative the homo Floresiensis grew to be so small on this particular island. Is it to do with natural predators or maybe the food? Anyone have any clue?
gpt
The are two phenomena that often affect species that get onto islands - island dwarfism and island giantism.   
Small species that get onto islands often leave large descendants. If they can arrive early with little competition and / or few predators then there's an opportunity for them to get much larger. There's a reason you get giant tortoises on multiple different islands.   
Large species though often get smaller. Limited resources for a population of large animals means that selection for smaller individuals who need less food etc. means they tend to shrink.   
Occasionally these can come together and you get the amazing phenomena on ancient Malta of giant swans with dwarf elephants (there's art online of this).  


In the case of Flores, this tended to be dwarfism with things like miniature humans, and also today you can see the anoa (dwarf buffalo) but there are also giant extinct storks that lived alongside H. floresiensis.   


TLDR limited resources means evolution selects for smaller individuals who can survive on little.