KYOTO, Japan, Jan. 13 (UPI) -- Scientists in Japan say 30 years of studying macaques monkeys has given them insight in the cultural evolution of humans.
Scientists at the Primate Research Center in Kyoto have watched generations of macaques pass stone-handling techniques from mother to child, said Michael A. Huffman, a primatologist at the center.
In their study, stone-handling included rubbing and clacking stones together, hitting them onto hard surfaces, picking them up, and cuddling, carrying, pushing, rolling and tossing stones.
The scientists found the stone-handling behavior changed with each generation as individual monkeys contributed their own patterns of stone-handling.
"Research on such transformation may shed light on the evolution of stone-tool use in early hominids," Huffman said.