Simplify the following text for a Grade 6 native English-speaking person.
Original: Wright had a long standing and sometimes bitter debate about this with R.A. Fisher , who felt that most populations in nature were too large for the effects of genetic drift to be important .
Simplified: Wright had a long standing and bitter debate about this with R. A. Fisher , who felt that most populations in nature were too large for these effects of genetic drift to be important .