Simplify the following text for a Grade 10 native English-speaking person.
Original: When populations within a species become isolated by geography , feeding strategy , mate selection , or other means , they may start to differ from other populations through genetic drift and natural selection , and over time may evolve into new species .
Simplified: When populations of organisms get isolated , the sub-populations will start to differ by genetic drift and natural selection over a period of time . This way , they will evolve into new species .