sentences:  Until about 14,000 years ago, it was connected to Ireland, and as recently as 8,000 years ago it retained a land connection to the continent, with an area of mostly low marshland joining it to what are now Denmark and the Netherlands.In Cheddar Gorge, near Bristol, the remains of animal species native to mainland Europe such as antelopes, brown bears, and wild horses have been found alongside a human skeleton, 'Cheddar Man', dated to about 7150 BC.Great Britain became an island at the end of the last glacial period when sea levels rose due to the combination of melting glaciers and the subsequent isostatic rebound of the crust.