Really, you do. While our cultures may divide us, our DNA demonstrates the fact that we are all descended from a small group of humans who lived in Africa.
Analysis of human genetic material shows that the most common recent ancestor of all men is a man who lived 50-60,000 years ago. The most common recent ancestor of all women is a woman who lived about 150,000 years ago.
Modern humans originated in eastern Africa, and migrated from Africa to Asia, then on to Australia. Meanwhile a band moved into Europe and rapidly displaced Neanderthals. America was probably the last continent to be occupied by Homo sapiens sapiens.
The common genetic ancestor of Neanderthal and modern humans lived about 706,000 years ago. The ancestors of all humans and Neanderthals split into two separate species some 330,000 years later. Recent DNA research indicates that while Neanderthals were in fact a different species from our own, we still share 99.5% of their genome. We share 98% of our genome with chimpanzees.
It's a small world after all, at least as far as our DNA is concerned.