Why the Fava Bean's Genome is 4 Times Larger Than Humans!

Video by KNOW (KnowNow).

Fava beans are the dried beans of the Vicia faba species of the legume family. They're the same species as the fresh or frozen green broad beans more familiar in British cooking but fava beans are the fully mature dried fruit of smaller seeded varieties.
But here’s a fun fact: the genome of the humble fava bean is four times larger than that of humans!
Surprising, right?
So, why is this the case?
This video explains!