A future physical anthropologist who knows nothing about the human race and would dig up a contemporary desktop computer, might conclude homo desktopus must have been the user of the device.
Funny picture? Gross? Seriously: from a sensorial point of view, the computers we currently use are extremely limited machines. The average desktop computer setup consists of a mouse, keyboard, a flat 2D screen and two small speakers. They engage only a fraction of the human sensory bandwidth.
If evolution would naturally select the human race on desktop computer use, people would evolve towards one-eyed blobs with tiny ears, a small mouth, no nose and a large click finger and no other sensory organs.
Will this be your grand-grand-grand-... son? Now seriously: Creating computer interfaces that better fit our bodily properties, will probably work quicker that evolutionary adapting to our current computer interfaces.
See also: Fake-space race, Third life, Study finds humans still evolving.