Mitochondrial Eve

I was surfing the internet a couple weeks back and i came across a video of an atheist scientist talking about mitochondrial Eve. For those who don't know, your DNA is made up of around a 50/50 split between your mom and dad's DNA. Apparently tho the mitochondria (the cell's power plant as i was taught in biology class) DNA is 100% from your mother. So this allows scientists to trace back every human's mother and their mother's mother and their mother's mother's mother and so on with 100% certainty. Scientists then came to the conclusion that all human being on this planet have a common ancestor and they called her mitochondrial Eve. This is not only possible proof of the existence of Eve, but also a point that proves how illogical racism is. With all our distinctions we are all, literally all 7.4 billion of us, related.