How did europe use social darwinism to justify empire building

Which of the following acts or treaties tried to american indians?

When gandhi reached the arabian sea at the end of the salt march, he picked up raw salt from the water and made a declaration: “with this, i am shaking the foundations of the british empire.” how do you think this quotation is symbolic of gandhi’s works and philosophy?

How did the geography of the arabian peninsula affect its religious and cultural diversity?