Nature Census

Someday you'll be able to type in "Dublin Ireland 16 June 1904" at a website and get a detailed inventory of likely species of plant and animal that could have been found there then.

Ulysses is wildlife-poor: a spiderweb, two flies, a moth, gulls, ferns...

A similar database could track people in places over time. Ireland was pretty advanced to take detailed censuses, with names and addresses and other biographical data, in 1901 and 1911.

Older times have to be estimated algorithmically.

A SimCity-like algorithm can guess neighborhoods past growth.