Years ago in high school my sister decided to do a harvest decoration during Halloween (gourds and pumpkins on display). Once they started to rot we threw them in a leaf pile and burned them in the back yard. The next year we had gourds and pumpkins growing there that wound up crossing. Green pumpkins, orange gourds....we took the results to the school and the biology teacher used them for a genetics lesson.

Not squash obviously but another easy starting point for someone getting into this field.