Changing Feet Due To Barefooting

"Standing between these tribes and the rest of the world is Possuelo, 59, who has pinpointed 7 new tribes in his 40 years as a sertanista, the peculiarly Brazilian occupation of Indian tracker. He can look at a footprint in the forest and tell instantly whether it belongs to a forest Indian or a Brazilian settler by the gap between the first two toes: Indians always walk barefoot, so the big and middle toes splay from repeatedly gripping the earth. Over the years, his own foot has come to resemble those of the Indians."

The Last Tribal Battle

Thanks to JZ.