Q: In this task, we ask you to elaborate the sentence without changing its general meaning. You can do so by explaining further the input sentence, using more precise wording, adding qualifiers and auxiliary information etc.
The Swedish botanist and cytogeneticist Gunnar O ̈ stergren in 1945 noted how chromosomes may spread in a population because of their own ” parasitic ” nature .
A:
The earliest clear statement of how chromosomes may spread in a population not because of their positive fitness effects on the individual organism , but because of their own " parasitic " nature came from the Swedish botanist and cytogeneticist Gunnar O ̈ stergren in 1945 .