 Bafuputsi ba tswang Princeton University naheng ya United States le Uppsala University mane Sweden ba tlalehile mofuta o motjha o qalehileng melokong e mmedi feela, leha tshebetso ena ho dumelwa hore e nka nako e telele haholo, ka lebaka la ho qhotsa dipakeng tsa Darwin finch e atileng haholo, Geospiza fortes, le o tswang kantle wa cactus finch, Geospiza conirostris. 