Simplify the following text for a Grade 9 native English-speaking person.
Original: The demarcation between hunter-gatherers and other societies which rely more upon domestication ( see agriculture and pastoralism and neolithic revolution ) is not clear-cut , as many contemporary societies combine both strategies to sustain their population .
Simplified: The line between hunter-gatherers and other societies like those who have agriculture as their basis is not a clear-cut one .