There's more to interaction than meets the eye: some issues in manual input

Imagine a time far into the future, when all knowledge about our civilization has been lost. Imagine further, that in the course of planting a garden, a fully stocked computer store from the 1980's was unearthed, and that all of the equipment and software was in working order. Now, based on this find, consider what a physical anthropologist might conclude about the physiology of the humans of our era? My best guess is that we would be pictured as having a well-developed eye, a long right arm, uniform-length fingers and a "low-fi" ear. But the dominating characteristic would be the prevalence of our visual system over our poorly developed manual dexterity.