fish hunter, kisumu

Lake Victoria is relatively young; its current basin formed only 400,000 years ago, when westward-flowing rivers were dammed by an upthrown crustal block. The lake's shallowness, limited river inflow, and large surface area relative to its volume make it vulnerable to climate changes; cores taken from its bottom show that Lake Victoria has dried up completely three times since it formed. These drying cycles are probably related to past ice ages, which are times when precipitation declined globally. The lake last dried out 17,300 years ago, and filled again beginning 14,700 years ago; the fantastic adaptive radiation of its native cichlids has taken place in the short period of time since then.