instruction:
In this task, we ask you to rewrite a sentence in simple English without changing its general meaning. Essentially, you want to make the sentence easier to read by using simpler words, utilizing more straightforward sentence structures, and omitting non-essential information etc.
question:
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 .
answer:
The Swedish botanist and cytogeneticist Gunnar O ̈ stergren in 1945 noted how chromosomes may spread in a population because of their own ” parasitic ” nature .


question:
O ̈ rebro Sportklubb , more commonly known as O ̈ rebro SK , O ̈ rebro or ( especially locally ) O ̈ SK , are a Swedish professional football club based in O ̈ rebro .
answer:
O ̈ rebro SK is an association football club in the town of O ̈ rebro in Sweden .


question:
It was named after the Yazoo River , which , in turn was named by the French explorer Robert La Salle in 1682 as " Rivie ̀ re des Yazous " in reference to the Yazoo tribe living near the river 's mouth .
answer:

Yazoo city was named after the Yazoo River , which was named by the French explorer Robert La Salle in 1682 .