I don't know if there are options to choose from, but in my opinion, the sentences that express the main argument are: <span>These early drifts we conjecture and know must have occurred, just as we know that the first upright-walking brutes were descended from some kin of the quadrumana through having developed "a pair of great toes out of two opposable thumbs." In London's view, these "drifts" or migrations must have happened just like a natural evolution must have happened. Whatever evolves, must migrate, in search of food.
</span><span>From Central Europe the Aryans have drifted into Asia, and from Central Asia the Turanians have drifted across Europe. There is the proof for his thesis: Aryans and Turanians drifted not because they were fond of wandering about, but because they had a clear goal in front of them: to find more food and resources, just like any other animal.</span>
Synonym clue, because a Synonym is a word that is exactly like or nearly like another word, if the word trying to be explained is explained by comparing it to another word is is exactly or nearly like it it is a Synonym Clue.
