Final answer:
The term "mother culture" used to describe the Olmec refers to the idea that the Olmec civilization was the foundation for later Mesoamerican cultures such as the Maya and Aztec. Evidence for this includes shared cultural aspects like religious symbols, games, and artifacts found throughout the region. Yet, the actual extent of Olmec influence remains debatable due to gaps in the archaeological record.
Step-by-step explanation:
When researchers refer to the Olmec civilization as a "mother culture," they mean that it served as a foundational civilization from which other Mesoamerican cultures are believed to have evolved. The term implies the Olmecs were the first to develop the cultural practices, religious concepts, and social structures later seen among the Maya, the Aztec, and other Mesoamerican civilizations. The evidence in support of the Olmec as a mother culture includes their development of religious motifs, ball games, and distinct monuments such as colossal stone heads, all of which can be found in later cultures. Notably, Olmec artifacts and influence have been identified as far afield as western Mexico and El Salvador. However, some scholars challenge the extent of the Olmecs' influence, given the diversity of Mesoamerica's geography and the sparse archaeological record from the time of Olmec decline around 400 BCE.