It suggested that people in Central and South America first

It suggested that people in Central and South America first gathered the cacao plant much earlier and for a different use than experts once thought.
The researchers believe it was the interest in cacao as an alcoholic drink that led to the use of its bitter seeds to make what is now known as chocolate.
第一句and是和谁并列的？
第二句to make前面有个led to,怎么还会有to make，