Thanks for the info.
My remark about agriculture was in response to remarks about the Picts and Celts in note 5.
The elephants they were hunting were also downsized (about 4 feet tall) as is common for species marooned on an island with limited food supply.
There are several arctic islands where whoolly mammoths survived for thousands of years after their continental cousins died out, by downsizing themselves (through selection) in just this way.