How do we notice the improvement in the technique for making tools for hunting wild animals? When did such change occur?

How do we notice the improvement in the technique for making tools for

1.	How do we notice the improvement in the technique for making tools for hunting wild animals? When did such change occur?
Answer» Solution :With the use of STONE TOOLS LIKE spear throwers, bow and ARROW, we notice the IMPROVEMENT in technique fro making tools. Such changes occurred around 35,000 years ago.