I can imagine it starting off as noticing the the Antelope follow natural ridges in the land and lying in wait at the end of a ridge to ambush the animals. Later they build artificial ridges and then low walls. Finally, they add the kill pits and iterate on the wall layouts to produce the sophisticated guiding shapes shown in the article. Interesting stuff.
Or it could have started by building a kill pit at the end of a natural ridge/wall/stream, and using dozens of men to force the antelopes along the path to the pit. Then someone said "wait, if we build another barrier on the other side, we could do this with fewer men...
But either way, I doubt they were just chasing antelopes across flat land and one dude said "Eureka! I've got it!"
