In an area in Africa, temporary pools form where rivers flow during the rainy months. Some fish have developed the ability to use their ventral fins as "feet" to travel on land from one of these temporary pools to another. Other fish in these pools die when the pools dry up. What can be expected to happen in this area after many years?

(1) The fish using ventral fins as "feet" will be present in increasing numbers.
(2) "feet" in the form of ventral fins will develop on all fish.
(3) The fish using ventral fins as as "feet" will develop real feet.
(4) All of the varieties of fish will survive and produce many offspring.