Why do agricultural hearths have geographical similarities

When looking at the spread of new ideas, we start with the place where that idea emerged. We call this a hearth, so an agricultural hearth would be the place where farming was first developed. This was easier than roaming around hunting and gathering, and so this part of the world became the first agricultural hearth.

20: 5

explanation:

about 20% of the world's population lives in   southwest asia, but on less than 5% of the world's   land area.