became globally important

Tryptophan

Lysine

Maize has the amino acid that beans dont

Beans lack one essential amino acid

Beans have one of the amino acids that maize doesnt

Maize lacks two essential amino acids - lysine and trptophan

Can be grown in the same place, save space so can produce more. Complementary nutritionally

It is softened by soaking in lime

They add protein as there as no animals in the triad

tuber, fruit, nut

No protein or fat, so must hunt or collect turtles

the whole root can be eaten

99% carbohydrate

can be stored underground for 2 years

Difficult to prepare - contains cyanide

Difficult to prepare - contains cyanide

Can be stored underground for up to years

Whole root can be eaten

No protein or fat, so must hunt or collect turtles

99% carbohydrate

cannot carry people/ pull wheeled vehicles/ plough

Olmec wheeled childrens toys from 1,500 BP, found at Tres Zapotes, Mexico