The pumpkin would not exist if the megafauna (mastadons, mammoths, giant sloth) of the pleistocene era hadn’t gone extinct and if humans hadn’t intervened.

The cucurbits family consists of gourds and squashes and 12,000 years ago were bitter and toxic to humans. However the megafauna ate them and dispersed the seeds, so the plants were abundant. After the megafauna died off, they should have gone extinct as well.

Humans started to use cucurbits for containers and tools. The plants were further domesticated and became less bitter and toxic. It has been suggested that cucurbits had been domesticated at least six different times in six different areas. This led to modern day pumpkins and squashes.